feat: implement typed events (#10889)

docs/api/index.md

@@ -46,12 +46,12 @@ sidebar_label: API
 ## Enumerations
 
 | Enumeration                                                           | Description                                                           |
-| ------------------------------------------------------------------------- | --------------------------------------------------------------------- |
+| --------------------------------------------------------------------- | --------------------------------------------------------------------- |
-| [BrowserContextEmittedEvents](./puppeteer.browsercontextemittedevents.md) |                                                                       |
+| [BrowserContextEvent](./puppeteer.browsercontextevent.md)             |                                                                       |
-| [BrowserEmittedEvents](./puppeteer.browseremittedevents.md)               | All the events a [browser instance](./puppeteer.browser.md) may emit. |
+| [BrowserEvent](./puppeteer.browserevent.md)                           | All the events a [browser instance](./puppeteer.browser.md) may emit. |
 | [InterceptResolutionAction](./puppeteer.interceptresolutionaction.md) |                                                                       |
-| [LocatorEmittedEvents](./puppeteer.locatoremittedevents.md)               | All the events that a locator instance may emit.                      |
+| [LocatorEvent](./puppeteer.locatorevent.md)                           | All the events that a locator instance may emit.                      |
-| [PageEmittedEvents](./puppeteer.pageemittedevents.md)                     | All the events that a page instance may emit.                         |
+| [PageEvent](./puppeteer.pageevent.md)                                 | All the events that a page instance may emit.                         |
 | [TargetType](./puppeteer.targettype.md)                               |                                                                       |
 
 ## Functions
@@ -66,14 +66,17 @@ sidebar_label: API
 ## Interfaces
 
 | Interface                                                                   | Description                                                                                                                                                                         |
-| --------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| --------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | [ActionOptions](./puppeteer.actionoptions.md)                               |                                                                                                                                                                                     |
 | [AutofillData](./puppeteer.autofilldata.md)                                 |                                                                                                                                                                                     |
 | [BoundingBox](./puppeteer.boundingbox.md)                                   |                                                                                                                                                                                     |
 | [BoxModel](./puppeteer.boxmodel.md)                                         |                                                                                                                                                                                     |
 | [BrowserConnectOptions](./puppeteer.browserconnectoptions.md)               | Generic browser options that can be passed when launching any browser or when connecting to an existing browser instance.                                                           |
+| [BrowserContextEvents](./puppeteer.browsercontextevents.md)                 |                                                                                                                                                                                     |
 | [BrowserContextOptions](./puppeteer.browsercontextoptions.md)               | BrowserContext options.                                                                                                                                                             |
+| [BrowserEvents](./puppeteer.browserevents.md)                               |                                                                                                                                                                                     |
 | [BrowserLaunchArgumentOptions](./puppeteer.browserlaunchargumentoptions.md) | Launcher options that only apply to Chrome.                                                                                                                                         |
+| [CDPSessionEvents](./puppeteer.cdpsessionevents.md)                         |                                                                                                                                                                                     |
 | [ClickOptions](./puppeteer.clickoptions.md)                                 |                                                                                                                                                                                     |
 | [CommonEventEmitter](./puppeteer.commoneventemitter.md)                     |                                                                                                                                                                                     |
 | [Configuration](./puppeteer.configuration.md)                               | <p>Defines options to configure Puppeteer's behavior during installation and runtime.</p><p>See individual properties for more information.</p>                                     |
@@ -88,6 +91,7 @@ sidebar_label: API
 | [Device](./puppeteer.device.md)                                             |                                                                                                                                                                                     |
 | [FrameAddScriptTagOptions](./puppeteer.frameaddscripttagoptions.md)         |                                                                                                                                                                                     |
 | [FrameAddStyleTagOptions](./puppeteer.frameaddstyletagoptions.md)           |                                                                                                                                                                                     |
+| [FrameEvents](./puppeteer.frameevents.md)                                   |                                                                                                                                                                                     |
 | [FrameWaitForFunctionOptions](./puppeteer.framewaitforfunctionoptions.md)   |                                                                                                                                                                                     |
 | [GeolocationOptions](./puppeteer.geolocationoptions.md)                     |                                                                                                                                                                                     |
 | [InterceptResolutionState](./puppeteer.interceptresolutionstate.md)         |                                                                                                                                                                                     |
@@ -97,7 +101,7 @@ sidebar_label: API
 | [KeyboardTypeOptions](./puppeteer.keyboardtypeoptions.md)                   |                                                                                                                                                                                     |
 | [KeyDownOptions](./puppeteer.keydownoptions.md)                             |                                                                                                                                                                                     |
 | [LaunchOptions](./puppeteer.launchoptions.md)                               | Generic launch options that can be passed when launching any browser.                                                                                                               |
-| [LocatorEventObject](./puppeteer.locatoreventobject.md)                     |                                                                                                                                                                                                     |
+| [LocatorEvents](./puppeteer.locatorevents.md)                               |                                                                                                                                                                                     |
 | [LocatorOptions](./puppeteer.locatoroptions.md)                             |                                                                                                                                                                                     |
 | [LocatorScrollOptions](./puppeteer.locatorscrolloptions.md)                 |                                                                                                                                                                                     |
 | [MediaFeature](./puppeteer.mediafeature.md)                                 |                                                                                                                                                                                     |
@@ -110,7 +114,7 @@ sidebar_label: API
 | [NetworkConditions](./puppeteer.networkconditions.md)                       |                                                                                                                                                                                     |
 | [NewDocumentScriptEvaluation](./puppeteer.newdocumentscriptevaluation.md)   |                                                                                                                                                                                     |
 | [Offset](./puppeteer.offset.md)                                             |                                                                                                                                                                                     |
-| [PageEventObject](./puppeteer.pageeventobject.md)                           | <p>Denotes the objects received by callback functions for page events.</p><p>See [PageEmittedEvents](./puppeteer.pageemittedevents.md) for more detail on the events and when they are emitted.</p> |
+| [PageEvents](./puppeteer.pageevents.md)                                     | <p>Denotes the objects received by callback functions for page events.</p><p>See [PageEvent](./puppeteer.pageevent.md) for more detail on the events and when they are emitted.</p> |
 | [PDFMargin](./puppeteer.pdfmargin.md)                                       |                                                                                                                                                                                     |
 | [PDFOptions](./puppeteer.pdfoptions.md)                                     | Valid options to configure PDF generation via [Page.pdf()](./puppeteer.page.pdf.md).                                                                                                |
 | [Point](./puppeteer.point.md)                                               |                                                                                                                                                                                     |
@@ -155,13 +159,14 @@ sidebar_label: API
 | [Awaitable](./puppeteer.awaitable.md)                                     |                                                                                                                                                         |
 | [AwaitableIterable](./puppeteer.awaitableiterable.md)                     |                                                                                                                                                         |
 | [AwaitedLocator](./puppeteer.awaitedlocator.md)                           |                                                                                                                                                         |
+| [CDPEvents](./puppeteer.cdpevents.md)                                     |                                                                                                                                                         |
 | [ChromeReleaseChannel](./puppeteer.chromereleasechannel.md)               |                                                                                                                                                         |
 | [ConsoleMessageType](./puppeteer.consolemessagetype.md)                   | The supported types for console messages.                                                                                                               |
 | [ElementFor](./puppeteer.elementfor.md)                                   |                                                                                                                                                         |
 | [ErrorCode](./puppeteer.errorcode.md)                                     |                                                                                                                                                         |
 | [EvaluateFunc](./puppeteer.evaluatefunc.md)                               |                                                                                                                                                         |
 | [EvaluateFuncWith](./puppeteer.evaluatefuncwith.md)                       |                                                                                                                                                         |
-| [EventType](./puppeteer.eventtype.md)                                     |                                                                                                                                                         |
+| [EventsWithWildcard](./puppeteer.eventswithwildcard.md)                   |                                                                                                                                                         |
 | [ExperimentsConfiguration](./puppeteer.experimentsconfiguration.md)       | <p>Defines experiment options for Puppeteer.</p><p>See individual properties for more information.</p>                                                  |
 | [FlattenHandle](./puppeteer.flattenhandle.md)                             |                                                                                                                                                         |
 | [HandleFor](./puppeteer.handlefor.md)                                     |                                                                                                                                                         |

docs/api/puppeteer.browser.md

@@ -9,16 +9,16 @@ A Browser is created when Puppeteer connects to a browser instance, either throu
 #### Signature:
 
 ```typescript
-export declare class Browser extends EventEmitter implements AsyncDisposable, Disposable
+export declare class Browser extends EventEmitter<BrowserEvents> implements AsyncDisposable, Disposable
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[BrowserEvents](./puppeteer.browserevents.md)&gt;
 
 **Implements:** AsyncDisposable, Disposable
 
 ## Remarks
 
-The Browser class extends from Puppeteer's [EventEmitter](./puppeteer.eventemitter.md) class and will emit various events which are documented in the [BrowserEmittedEvents](./puppeteer.browseremittedevents.md) enum.
+The Browser class extends from Puppeteer's [EventEmitter](./puppeteer.eventemitter.md) class and will emit various events which are documented in the [BrowserEvent](./puppeteer.browserevent.md) enum.
 
 The constructor for this class is marked as internal. Third-party code should not call the constructor directly or create subclasses that extend the `Browser` class.
 

docs/api/puppeteer.browsercontext.md

@@ -9,14 +9,14 @@ BrowserContexts provide a way to operate multiple independent browser sessions.
 #### Signature:
 
 ```typescript
-export declare class BrowserContext extends EventEmitter
+export declare class BrowserContext extends EventEmitter<BrowserContextEvents>
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[BrowserContextEvents](./puppeteer.browsercontextevents.md)&gt;
 
 ## Remarks
 
-The Browser class extends from Puppeteer's [EventEmitter](./puppeteer.eventemitter.md) class and will emit various events which are documented in the [BrowserContextEmittedEvents](./puppeteer.browsercontextemittedevents.md) enum.
+The Browser class extends from Puppeteer's [EventEmitter](./puppeteer.eventemitter.md) class and will emit various events which are documented in the [BrowserContextEvents](./puppeteer.browsercontextevents.md) enum.
 
 If a page opens another page, e.g. with a `window.open` call, the popup will belong to the parent page's browser context.
 

docs/api/puppeteer.browsercontextevent.md

@@ -1,13 +1,13 @@
 ---
-sidebar_label: BrowserContextEmittedEvents
+sidebar_label: BrowserContextEvent
 ---
 
-# BrowserContextEmittedEvents enum
+# BrowserContextEvent enum
 
 #### Signature:
 
 ```typescript
-export declare const enum BrowserContextEmittedEvents
+export declare const enum BrowserContextEvent
 ```
 
 ## Enumeration Members

docs/api/puppeteer.browsercontextevents.md

@@ -0,0 +1,21 @@
+---
+sidebar_label: BrowserContextEvents
+---
+
+# BrowserContextEvents interface
+
+#### Signature:
+
+```typescript
+export interface BrowserContextEvents extends Record<EventType, unknown>
+```
+
+**Extends:** Record&lt;EventType, unknown&gt;
+
+## Properties
+
+| Property        | Modifiers | Type                            | Description | Default |
+| --------------- | --------- | ------------------------------- | ----------- | ------- |
+| targetchanged   |           | [Target](./puppeteer.target.md) |             |         |
+| targetcreated   |           | [Target](./puppeteer.target.md) |             |         |
+| targetdestroyed |           | [Target](./puppeteer.target.md) |             |         |

docs/api/puppeteer.browserevent.md

@@ -1,15 +1,15 @@
 ---
-sidebar_label: BrowserEmittedEvents
+sidebar_label: BrowserEvent
 ---
 
-# BrowserEmittedEvents enum
+# BrowserEvent enum
 
 All the events a [browser instance](./puppeteer.browser.md) may emit.
 
 #### Signature:
 
 ```typescript
-export declare const enum BrowserEmittedEvents
+export declare const enum BrowserEvent
 ```
 
 ## Enumeration Members

docs/api/puppeteer.browserevents.md

@@ -0,0 +1,22 @@
+---
+sidebar_label: BrowserEvents
+---
+
+# BrowserEvents interface
+
+#### Signature:
+
+```typescript
+export interface BrowserEvents extends Record<EventType, unknown>
+```
+
+**Extends:** Record&lt;EventType, unknown&gt;
+
+## Properties
+
+| Property        | Modifiers | Type                            | Description | Default |
+| --------------- | --------- | ------------------------------- | ----------- | ------- |
+| disconnected    |           | undefined                       |             |         |
+| targetchanged   |           | [Target](./puppeteer.target.md) |             |         |
+| targetcreated   |           | [Target](./puppeteer.target.md) |             |         |
+| targetdestroyed |           | [Target](./puppeteer.target.md) |             |         |

docs/api/puppeteer.cdpevents.md

@@ -0,0 +1,13 @@
+---
+sidebar_label: CDPEvents
+---
+
+# CDPEvents type
+
+#### Signature:
+
+```typescript
+export type CDPEvents = {
+  [Property in keyof ProtocolMapping.Events]: ProtocolMapping.Events[Property][0];
+};
+```

docs/api/puppeteer.cdpsession.md

@@ -9,10 +9,10 @@ The `CDPSession` instances are used to talk raw Chrome Devtools Protocol.
 #### Signature:
 
 ```typescript
-export declare class CDPSession extends EventEmitter
+export declare abstract class CDPSession extends EventEmitter<CDPSessionEvents>
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[CDPSessionEvents](./puppeteer.cdpsessionevents.md)&gt;
 
 ## Remarks
 

docs/api/puppeteer.cdpsessionevents.md

@@ -0,0 +1,13 @@
+---
+sidebar_label: CDPSessionEvents
+---
+
+# CDPSessionEvents interface
+
+#### Signature:
+
+```typescript
+export interface CDPSessionEvents extends CDPEvents, Record<EventType, unknown>
+```
+
+**Extends:** [CDPEvents](./puppeteer.cdpevents.md), Record&lt;EventType, unknown&gt;

docs/api/puppeteer.commoneventemitter.addlistener.md

@@ -8,16 +8,19 @@ sidebar_label: CommonEventEmitter.addListener
 
 ```typescript
 interface CommonEventEmitter {
-  addListener(event: EventType, handler: Handler): this;
+  addListener<Key extends keyof Events>(
+    type: Key,
+    handler: Handler<Events[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                   | Description |
-| --------- | ------------------------------------- | ----------- |
+| --------- | ------------------------------------------------------ | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md) |             |
+| type      | Key                                                    |             |
-| handler   | [Handler](./puppeteer.handler.md)     |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;Events\[Key\]&gt; |             |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.emit.md

@@ -8,16 +8,16 @@ sidebar_label: CommonEventEmitter.emit
 
 ```typescript
 interface CommonEventEmitter {
-  emit(event: EventType, eventData?: unknown): boolean;
+  emit<Key extends keyof Events>(type: Key, event: Events[Key]): boolean;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type          | Description |
-| --------- | ------------------------------------- | ------------ |
+| --------- | ------------- | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md) |              |
+| type      | Key           |             |
-| eventData | unknown                               | _(Optional)_ |
+| event     | Events\[Key\] |             |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.listenercount.md

@@ -8,15 +8,15 @@ sidebar_label: CommonEventEmitter.listenerCount
 
 ```typescript
 interface CommonEventEmitter {
-  listenerCount(event: string): number;
+  listenerCount(event: keyof Events): number;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type         | Description |
-| --------- | ------ | ----------- |
+| --------- | ------------ | ----------- |
-| event     | string |             |
+| event     | keyof Events |             |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.md

@@ -7,18 +7,18 @@ sidebar_label: CommonEventEmitter
 #### Signature:
 
 ```typescript
-export interface CommonEventEmitter
+export interface CommonEventEmitter<Events extends Record<EventType, unknown>>
 ```
 
 ## Methods
 
 | Method                                                                            | Description |
-| ---------------------------------------------------------------------------------- | ----------- |
+| --------------------------------------------------------------------------------- | ----------- |
-| [addListener(event, handler)](./puppeteer.commoneventemitter.addlistener.md)       |             |
+| [addListener(type, handler)](./puppeteer.commoneventemitter.addlistener.md)       |             |
-| [emit(event, eventData)](./puppeteer.commoneventemitter.emit.md)                   |             |
+| [emit(type, event)](./puppeteer.commoneventemitter.emit.md)                       |             |
 | [listenerCount(event)](./puppeteer.commoneventemitter.listenercount.md)           |             |
-| [off(event, handler)](./puppeteer.commoneventemitter.off.md)                       |             |
+| [off(type, handler)](./puppeteer.commoneventemitter.off.md)                       |             |
-| [on(event, handler)](./puppeteer.commoneventemitter.on.md)                         |             |
+| [on(type, handler)](./puppeteer.commoneventemitter.on.md)                         |             |
-| [once(event, handler)](./puppeteer.commoneventemitter.once.md)                     |             |
+| [once(type, handler)](./puppeteer.commoneventemitter.once.md)                     |             |
 | [removeAllListeners(event)](./puppeteer.commoneventemitter.removealllisteners.md) |             |
-| [removeListener(event, handler)](./puppeteer.commoneventemitter.removelistener.md) |             |
+| [removeListener(type, handler)](./puppeteer.commoneventemitter.removelistener.md) |             |

docs/api/puppeteer.commoneventemitter.off.md

@@ -8,16 +8,19 @@ sidebar_label: CommonEventEmitter.off
 
 ```typescript
 interface CommonEventEmitter {
-  off(event: EventType, handler: Handler): this;
+  off<Key extends keyof Events>(
+    type: Key,
+    handler?: Handler<Events[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                   | Description  |
-| --------- | ------------------------------------- | ----------- |
+| --------- | ------------------------------------------------------ | ------------ |
-| event     | [EventType](./puppeteer.eventtype.md) |             |
+| type      | Key                                                    |              |
-| handler   | [Handler](./puppeteer.handler.md)     |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;Events\[Key\]&gt; | _(Optional)_ |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.on.md

@@ -8,16 +8,16 @@ sidebar_label: CommonEventEmitter.on
 
 ```typescript
 interface CommonEventEmitter {
-  on(event: EventType, handler: Handler): this;
+  on<Key extends keyof Events>(type: Key, handler: Handler<Events[Key]>): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                   | Description |
-| --------- | ------------------------------------- | ----------- |
+| --------- | ------------------------------------------------------ | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md) |             |
+| type      | Key                                                    |             |
-| handler   | [Handler](./puppeteer.handler.md)     |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;Events\[Key\]&gt; |             |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.once.md

@@ -8,16 +8,19 @@ sidebar_label: CommonEventEmitter.once
 
 ```typescript
 interface CommonEventEmitter {
-  once(event: EventType, handler: Handler): this;
+  once<Key extends keyof Events>(
+    type: Key,
+    handler: Handler<Events[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                   | Description |
-| --------- | ------------------------------------- | ----------- |
+| --------- | ------------------------------------------------------ | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md) |             |
+| type      | Key                                                    |             |
-| handler   | [Handler](./puppeteer.handler.md)     |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;Events\[Key\]&gt; |             |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.removealllisteners.md

@@ -8,15 +8,15 @@ sidebar_label: CommonEventEmitter.removeAllListeners
 
 ```typescript
 interface CommonEventEmitter {
-  removeAllListeners(event?: EventType): this;
+  removeAllListeners(event?: keyof Events): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type         | Description  |
-| --------- | ------------------------------------- | ------------ |
+| --------- | ------------ | ------------ |
-| event     | [EventType](./puppeteer.eventtype.md) | _(Optional)_ |
+| event     | keyof Events | _(Optional)_ |
 
 **Returns:**
 

docs/api/puppeteer.commoneventemitter.removelistener.md

@@ -8,16 +8,19 @@ sidebar_label: CommonEventEmitter.removeListener
 
 ```typescript
 interface CommonEventEmitter {
-  removeListener(event: EventType, handler: Handler): this;
+  removeListener<Key extends keyof Events>(
+    type: Key,
+    handler: Handler<Events[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                   | Description |
-| --------- | ------------------------------------- | ----------- |
+| --------- | ------------------------------------------------------ | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md) |             |
+| type      | Key                                                    |             |
-| handler   | [Handler](./puppeteer.handler.md)     |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;Events\[Key\]&gt; |             |
 
 **Returns:**
 

docs/api/puppeteer.connection.md

@@ -7,10 +7,10 @@ sidebar_label: Connection
 #### Signature:
 
 ```typescript
-export declare class Connection extends EventEmitter
+export declare class Connection extends EventEmitter<CDPSessionEvents>
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[CDPSessionEvents](./puppeteer.cdpsessionevents.md)&gt;
 
 ## Constructors
 

docs/api/puppeteer.eventemitter.addlistener.md

@@ -14,16 +14,19 @@ Add an event listener.
 
 ```typescript
 class EventEmitter {
-  addListener(event: EventType, handler: Handler<any>): this;
+  addListener<Key extends keyof EventsWithWildcard<Events>>(
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                                                                  | Description |
-| --------- | -------------------------------------------- | ----------- |
+| --------- | --------------------------------------------------------------------------------------------------------------------- | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md)        |             |
+| type      | Key                                                                                                                   |             |
-| handler   | [Handler](./puppeteer.handler.md)&lt;any&gt; |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;[EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;\[Key\]&gt; |             |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.emit.md

@@ -10,16 +10,19 @@ Emit an event and call any associated listeners.
 
 ```typescript
 class EventEmitter {
-  emit(event: EventType, eventData?: unknown): boolean;
+  emit<Key extends keyof EventsWithWildcard<Events>>(
+    type: Key,
+    event: EventsWithWildcard<Events>[Key]
+  ): boolean;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                         | Description                  |
-| --------- | ------------------------------------- | ------------------------------------------------------- |
+| --------- | ---------------------------------------------------------------------------- | ---------------------------- |
-| event     | [EventType](./puppeteer.eventtype.md) | the event you'd like to emit                            |
+| type      | Key                                                                          | the event you'd like to emit |
-| eventData | unknown                               | _(Optional)_ any data you'd like to emit with the event |
+| event     | [EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;\[Key\] |                              |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.listenercount.md

@@ -10,15 +10,15 @@ Gets the number of listeners for a given event.
 
 ```typescript
 class EventEmitter {
-  listenerCount(event: EventType): number;
+  listenerCount(type: keyof EventsWithWildcard<Events>): number;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                        | Description                             |
-| --------- | ------------------------------------- | --------------------------------------- |
+| --------- | --------------------------------------------------------------------------- | --------------------------------------- |
-| event     | [EventType](./puppeteer.eventtype.md) | the event to get the listener count for |
+| type      | keyof [EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt; | the event to get the listener count for |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.md

@@ -9,10 +9,10 @@ The EventEmitter class that many Puppeteer classes extend.
 #### Signature:
 
 ```typescript
-export declare class EventEmitter implements CommonEventEmitter
+export declare class EventEmitter<Events extends Record<EventType, unknown>> implements CommonEventEmitter<EventsWithWildcard<Events>>
 ```
 
-**Implements:** [CommonEventEmitter](./puppeteer.commoneventemitter.md)
+**Implements:** [CommonEventEmitter](./puppeteer.commoneventemitter.md)&lt;[EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;&gt;
 
 ## Remarks
 
@@ -23,12 +23,12 @@ The constructor for this class is marked as internal. Third-party code should no
 ## Methods
 
 | Method                                                                      | Modifiers | Description                                                                                      |
-| ---------------------------------------------------------------------------- | --------- | ------------------------------------------------------------------------------------------------ |
+| --------------------------------------------------------------------------- | --------- | ------------------------------------------------------------------------------------------------ |
-| [addListener(event, handler)](./puppeteer.eventemitter.addlistener.md)       |           | Add an event listener.                                                                           |
+| [addListener(type, handler)](./puppeteer.eventemitter.addlistener.md)       |           | Add an event listener.                                                                           |
-| [emit(event, eventData)](./puppeteer.eventemitter.emit.md)                   |           | Emit an event and call any associated listeners.                                                 |
+| [emit(type, event)](./puppeteer.eventemitter.emit.md)                       |           | Emit an event and call any associated listeners.                                                 |
-| [listenerCount(event)](./puppeteer.eventemitter.listenercount.md)            |           | Gets the number of listeners for a given event.                                                  |
+| [listenerCount(type)](./puppeteer.eventemitter.listenercount.md)            |           | Gets the number of listeners for a given event.                                                  |
-| [off(event, handler)](./puppeteer.eventemitter.off.md)                       |           | Remove an event listener from firing.                                                            |
+| [off(type, handler)](./puppeteer.eventemitter.off.md)                       |           | Remove an event listener from firing.                                                            |
-| [on(event, handler)](./puppeteer.eventemitter.on.md)                         |           | Bind an event listener to fire when an event occurs.                                             |
+| [on(type, handler)](./puppeteer.eventemitter.on.md)                         |           | Bind an event listener to fire when an event occurs.                                             |
-| [once(event, handler)](./puppeteer.eventemitter.once.md)                     |           | Like <code>on</code> but the listener will only be fired once and then it will be removed.       |
+| [once(type, handler)](./puppeteer.eventemitter.once.md)                     |           | Like <code>on</code> but the listener will only be fired once and then it will be removed.       |
-| [removeAllListeners(event)](./puppeteer.eventemitter.removealllisteners.md)  |           | Removes all listeners. If given an event argument, it will remove only listeners for that event. |
+| [removeAllListeners(type)](./puppeteer.eventemitter.removealllisteners.md)  |           | Removes all listeners. If given an event argument, it will remove only listeners for that event. |
-| [removeListener(event, handler)](./puppeteer.eventemitter.removelistener.md) |           | Remove an event listener.                                                                        |
+| [removeListener(type, handler)](./puppeteer.eventemitter.removelistener.md) |           | Remove an event listener.                                                                        |

docs/api/puppeteer.eventemitter.off.md

@@ -10,16 +10,19 @@ Remove an event listener from firing.
 
 ```typescript
 class EventEmitter {
-  off(event: EventType, handler: Handler<any>): this;
+  off<Key extends keyof EventsWithWildcard<Events>>(
+    type: Key,
+    handler?: Handler<EventsWithWildcard<Events>[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                                                                  | Description                                       |
-| --------- | -------------------------------------------- | ----------------------------------------------- |
+| --------- | --------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- |
-| event     | [EventType](./puppeteer.eventtype.md)        | the event type you'd like to stop listening to. |
+| type      | Key                                                                                                                   | the event type you'd like to stop listening to.   |
-| handler   | [Handler](./puppeteer.handler.md)&lt;any&gt; | the function that should be removed.            |
+| handler   | [Handler](./puppeteer.handler.md)&lt;[EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;\[Key\]&gt; | _(Optional)_ the function that should be removed. |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.on.md

@@ -10,16 +10,19 @@ Bind an event listener to fire when an event occurs.
 
 ```typescript
 class EventEmitter {
-  on(event: EventType, handler: Handler<any>): this;
+  on<Key extends keyof EventsWithWildcard<Events>>(
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                                                                  | Description                                                        |
-| --------- | -------------------------------------------- | ------------------------------------------------------------------ |
+| --------- | --------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------ |
-| event     | [EventType](./puppeteer.eventtype.md)        | the event type you'd like to listen to. Can be a string or symbol. |
+| type      | Key                                                                                                                   | the event type you'd like to listen to. Can be a string or symbol. |
-| handler   | [Handler](./puppeteer.handler.md)&lt;any&gt; | the function to be called when the event occurs.                   |
+| handler   | [Handler](./puppeteer.handler.md)&lt;[EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;\[Key\]&gt; | the function to be called when the event occurs.                   |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.once.md

@@ -10,16 +10,19 @@ Like `on` but the listener will only be fired once and then it will be removed.
 
 ```typescript
 class EventEmitter {
-  once(event: EventType, handler: Handler<any>): this;
+  once<Key extends keyof EventsWithWildcard<Events>>(
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                                                                  | Description                                       |
-| --------- | -------------------------------------------- | ------------------------------------------------- |
+| --------- | --------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- |
-| event     | [EventType](./puppeteer.eventtype.md)        | the event you'd like to listen to                 |
+| type      | Key                                                                                                                   | the event you'd like to listen to                 |
-| handler   | [Handler](./puppeteer.handler.md)&lt;any&gt; | the handler function to run when the event occurs |
+| handler   | [Handler](./puppeteer.handler.md)&lt;[EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;\[Key\]&gt; | the handler function to run when the event occurs |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.removealllisteners.md

@@ -10,15 +10,15 @@ Removes all listeners. If given an event argument, it will remove only listeners
 
 ```typescript
 class EventEmitter {
-  removeAllListeners(event?: EventType): this;
+  removeAllListeners(type?: keyof EventsWithWildcard<Events>): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                        | Description                                     |
-| --------- | ------------------------------------- | ----------------------------------------------- |
+| --------- | --------------------------------------------------------------------------- | ----------------------------------------------- |
-| event     | [EventType](./puppeteer.eventtype.md) | _(Optional)_ the event to remove listeners for. |
+| type      | keyof [EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt; | _(Optional)_ the event to remove listeners for. |
 
 **Returns:**
 

docs/api/puppeteer.eventemitter.removelistener.md

@@ -14,16 +14,19 @@ Remove an event listener.
 
 ```typescript
 class EventEmitter {
-  removeListener(event: EventType, handler: Handler<any>): this;
+  removeListener<Key extends keyof EventsWithWildcard<Events>>(
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this;
 }
 ```
 
 ## Parameters
 
 | Parameter | Type                                                                                                                  | Description |
-| --------- | -------------------------------------------- | ----------- |
+| --------- | --------------------------------------------------------------------------------------------------------------------- | ----------- |
-| event     | [EventType](./puppeteer.eventtype.md)        |             |
+| type      | Key                                                                                                                   |             |
-| handler   | [Handler](./puppeteer.handler.md)&lt;any&gt; |             |
+| handler   | [Handler](./puppeteer.handler.md)&lt;[EventsWithWildcard](./puppeteer.eventswithwildcard.md)&lt;Events&gt;\[Key\]&gt; |             |
 
 **Returns:**
 

docs/api/puppeteer.eventswithwildcard.md

@@ -0,0 +1,14 @@
+---
+sidebar_label: EventsWithWildcard
+---
+
+# EventsWithWildcard type
+
+#### Signature:
+
+```typescript
+export type EventsWithWildcard<Events extends Record<EventType, unknown>> =
+  Events & {
+    '*': Events[keyof Events];
+  };
+```

docs/api/puppeteer.eventtype.md

@@ -1,11 +0,0 @@
----
-sidebar_label: EventType
----
-
-# EventType type
-
-#### Signature:
-
-```typescript
-export type EventType = string | symbol;
-```

docs/api/puppeteer.frame.md

@@ -11,16 +11,16 @@ To understand frames, you can think of frames as `<iframe>` elements. Just like
 #### Signature:
 
 ```typescript
-export declare abstract class Frame extends EventEmitter
+export declare abstract class Frame extends EventEmitter<FrameEvents>
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[FrameEvents](./puppeteer.frameevents.md)&gt;
 
 ## Remarks
 
 Frame lifecycles are controlled by three events that are all dispatched on the parent [page](./puppeteer.frame.page.md):
 
-- [PageEmittedEvents.FrameAttached](./puppeteer.pageemittedevents.md) - [PageEmittedEvents.FrameNavigated](./puppeteer.pageemittedevents.md) - [PageEmittedEvents.FrameDetached](./puppeteer.pageemittedevents.md)
+- [PageEvent.FrameAttached](./puppeteer.pageevent.md) - [PageEvent.FrameNavigated](./puppeteer.pageevent.md) - [PageEvent.FrameDetached](./puppeteer.pageevent.md)
 
 The constructor for this class is marked as internal. Third-party code should not call the constructor directly or create subclasses that extend the `Frame` class.
 

docs/api/puppeteer.frameevents.md

@@ -0,0 +1,13 @@
+---
+sidebar_label: FrameEvents
+---
+
+# FrameEvents interface
+
+#### Signature:
+
+```typescript
+export interface FrameEvents extends Record<EventType, unknown>
+```
+
+**Extends:** Record&lt;EventType, unknown&gt;

docs/api/puppeteer.locator.md

@@ -9,10 +9,10 @@ Locators describe a strategy of locating objects and performing an action on the
 #### Signature:
 
 ```typescript
-export declare abstract class Locator<T> extends EventEmitter
+export declare abstract class Locator<T> extends EventEmitter<LocatorEvents>
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[LocatorEvents](./puppeteer.locatorevents.md)&gt;
 
 ## Properties
 
@@ -31,9 +31,6 @@ export declare abstract class Locator<T> extends EventEmitter
 | [filter(predicate)](./puppeteer.locator.filter.md)                                                     |                     | <p>Creates an expectation that is evaluated against located values.</p><p>If the expectations do not match, then the locator will retry.</p>                                                                                             |
 | [hover(this, options)](./puppeteer.locator.hover.md)                                                   |                     |                                                                                                                                                                                                                                          |
 | [map(mapper)](./puppeteer.locator.map.md)                                                              |                     | Maps the locator using the provided mapper.                                                                                                                                                                                              |
-| [off(eventName, handler)](./puppeteer.locator.off.md)                                                  |                     |                                                                                                                                                                                                                                          |
-| [on(eventName, handler)](./puppeteer.locator.on.md)                                                    |                     |                                                                                                                                                                                                                                          |
-| [once(eventName, handler)](./puppeteer.locator.once.md)                                                |                     |                                                                                                                                                                                                                                          |
 | [race(locators)](./puppeteer.locator.race.md)                                                          | <code>static</code> | Creates a race between multiple locators but ensures that only a single one acts.                                                                                                                                                        |
 | [scroll(this, options)](./puppeteer.locator.scroll.md)                                                 |                     |                                                                                                                                                                                                                                          |
 | [setEnsureElementIsInTheViewport(this, value)](./puppeteer.locator.setensureelementisintheviewport.md) |                     |                                                                                                                                                                                                                                          |

docs/api/puppeteer.locator.off.md

@@ -1,27 +0,0 @@
----
-sidebar_label: Locator.off
----
-
-# Locator.off() method
-
-#### Signature:
-
-```typescript
-class Locator {
-  off<K extends keyof LocatorEventObject>(
-    eventName: K,
-    handler: (event: LocatorEventObject[K]) => void
-  ): this;
-}
-```
-
-## Parameters
-
-| Parameter | Type                                                                             | Description |
-| --------- | -------------------------------------------------------------------------------- | ----------- |
-| eventName | K                                                                                |             |
-| handler   | (event: [LocatorEventObject](./puppeteer.locatoreventobject.md)\[K\]) =&gt; void |             |
-
-**Returns:**
-
-this

docs/api/puppeteer.locator.on.md

@@ -1,27 +0,0 @@
----
-sidebar_label: Locator.on
----
-
-# Locator.on() method
-
-#### Signature:
-
-```typescript
-class Locator {
-  on<K extends keyof LocatorEventObject>(
-    eventName: K,
-    handler: (event: LocatorEventObject[K]) => void
-  ): this;
-}
-```
-
-## Parameters
-
-| Parameter | Type                                                                             | Description |
-| --------- | -------------------------------------------------------------------------------- | ----------- |
-| eventName | K                                                                                |             |
-| handler   | (event: [LocatorEventObject](./puppeteer.locatoreventobject.md)\[K\]) =&gt; void |             |
-
-**Returns:**
-
-this

docs/api/puppeteer.locator.once.md

@@ -1,27 +0,0 @@
----
-sidebar_label: Locator.once
----
-
-# Locator.once() method
-
-#### Signature:
-
-```typescript
-class Locator {
-  once<K extends keyof LocatorEventObject>(
-    eventName: K,
-    handler: (event: LocatorEventObject[K]) => void
-  ): this;
-}
-```
-
-## Parameters
-
-| Parameter | Type                                                                             | Description |
-| --------- | -------------------------------------------------------------------------------- | ----------- |
-| eventName | K                                                                                |             |
-| handler   | (event: [LocatorEventObject](./puppeteer.locatoreventobject.md)\[K\]) =&gt; void |             |
-
-**Returns:**
-
-this

docs/api/puppeteer.locatorevent.md

@@ -1,15 +1,15 @@
 ---
-sidebar_label: LocatorEmittedEvents
+sidebar_label: LocatorEvent
 ---
 
-# LocatorEmittedEvents enum
+# LocatorEvent enum
 
 All the events that a locator instance may emit.
 
 #### Signature:
 
 ```typescript
-export declare enum LocatorEmittedEvents
+export declare enum LocatorEvent
 ```
 
 ## Enumeration Members

docs/api/puppeteer.locatoreventobject.md

@@ -1,17 +0,0 @@
----
-sidebar_label: LocatorEventObject
----
-
-# LocatorEventObject interface
-
-#### Signature:
-
-```typescript
-export interface LocatorEventObject
-```
-
-## Properties
-
-| Property | Modifiers | Type  | Description | Default |
-| -------- | --------- | ----- | ----------- | ------- |
-| action   |           | never |             |         |

docs/api/puppeteer.locatorevents.md

@@ -0,0 +1,19 @@
+---
+sidebar_label: LocatorEvents
+---
+
+# LocatorEvents interface
+
+#### Signature:
+
+```typescript
+export interface LocatorEvents extends Record<EventType, unknown>
+```
+
+**Extends:** Record&lt;EventType, unknown&gt;
+
+## Properties
+
+| Property | Modifiers | Type      | Description | Default |
+| -------- | --------- | --------- | ----------- | ------- |
+| action   |           | undefined |             |         |

docs/api/puppeteer.page.md

@@ -15,10 +15,10 @@ One Browser instance might have multiple Page instances.
 #### Signature:
 
 ```typescript
-export declare abstract class Page extends EventEmitter implements AsyncDisposable, Disposable
+export declare abstract class Page extends EventEmitter<PageEvents> implements AsyncDisposable, Disposable
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;[PageEvents](./puppeteer.pageevents.md)&gt;
 
 **Implements:** AsyncDisposable, Disposable
 
@@ -42,7 +42,7 @@ import puppeteer from 'puppeteer';
 })();
 ```
 
-The Page class extends from Puppeteer's [EventEmitter](./puppeteer.eventemitter.md) class and will emit various events which are documented in the [PageEmittedEvents](./puppeteer.pageemittedevents.md) enum.
+The Page class extends from Puppeteer's [EventEmitter](./puppeteer.eventemitter.md) class and will emit various events which are documented in the [PageEvent](./puppeteer.pageevent.md) enum.
 
 ## Example 2
 
@@ -52,7 +52,7 @@ This example logs a message for a single page `load` event:
 page.once('load', () => console.log('Page loaded!'));
 ```
 
-To unsubscribe from events use the [Page.off()](./puppeteer.page.off.md) method:
+To unsubscribe from events use the [EventEmitter.off()](./puppeteer.eventemitter.off.md) method:
 
 ```ts
 function logRequest(interceptedRequest) {
@@ -126,9 +126,6 @@ page.off('request', logRequest);
 | [locator(func)](./puppeteer.page.locator_1.md)                                                             |           | Creates a locator for the provided function. See [Locator](./puppeteer.locator.md) for details and supported actions.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
 | [mainFrame()](./puppeteer.page.mainframe.md)                                                               |           | The page's main frame.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
 | [metrics()](./puppeteer.page.metrics.md)                                                                   |           | Object containing metrics as key/value pairs.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
-| [off(eventName, handler)](./puppeteer.page.off.md)                                                         |           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
-| [on(eventName, handler)](./puppeteer.page.on.md)                                                           |           | <p>Listen to page events.</p><p>:::note</p><p>This method exists to define event typings and handle proper wireup of cooperative request interception. Actual event listening and dispatching is delegated to [EventEmitter](./puppeteer.eventemitter.md).</p><p>:::</p>                                                                                                                                                                                                                                                                                                                                |
-| [once(eventName, handler)](./puppeteer.page.once.md)                                                       |           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
 | [pdf(options)](./puppeteer.page.pdf.md)                                                                    |           | Generates a PDF of the page with the <code>print</code> CSS media type.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
 | [queryObjects(prototypeHandle)](./puppeteer.page.queryobjects.md)                                          |           | This method iterates the JavaScript heap and finds all objects with the given prototype.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
 | [reload(options)](./puppeteer.page.reload.md)                                                              |           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |

docs/api/puppeteer.page.off.md

@@ -1,27 +0,0 @@
----
-sidebar_label: Page.off
----
-
-# Page.off() method
-
-#### Signature:
-
-```typescript
-class Page {
-  off<K extends keyof PageEventObject>(
-    eventName: K,
-    handler: (event: PageEventObject[K]) => void
-  ): this;
-}
-```
-
-## Parameters
-
-| Parameter | Type                                                                       | Description |
-| --------- | -------------------------------------------------------------------------- | ----------- |
-| eventName | K                                                                          |             |
-| handler   | (event: [PageEventObject](./puppeteer.pageeventobject.md)\[K\]) =&gt; void |             |
-
-**Returns:**
-
-this

docs/api/puppeteer.page.on.md

@@ -1,35 +0,0 @@
----
-sidebar_label: Page.on
----
-
-# Page.on() method
-
-Listen to page events.
-
-:::note
-
-This method exists to define event typings and handle proper wireup of cooperative request interception. Actual event listening and dispatching is delegated to [EventEmitter](./puppeteer.eventemitter.md).
-
-:::
-
-#### Signature:
-
-```typescript
-class Page {
-  on<K extends keyof PageEventObject>(
-    eventName: K,
-    handler: (event: PageEventObject[K]) => void
-  ): this;
-}
-```
-
-## Parameters
-
-| Parameter | Type                                                                       | Description |
-| --------- | -------------------------------------------------------------------------- | ----------- |
-| eventName | K                                                                          |             |
-| handler   | (event: [PageEventObject](./puppeteer.pageeventobject.md)\[K\]) =&gt; void |             |
-
-**Returns:**
-
-this

docs/api/puppeteer.page.once.md

@@ -1,27 +0,0 @@
----
-sidebar_label: Page.once
----
-
-# Page.once() method
-
-#### Signature:
-
-```typescript
-class Page {
-  once<K extends keyof PageEventObject>(
-    eventName: K,
-    handler: (event: PageEventObject[K]) => void
-  ): this;
-}
-```
-
-## Parameters
-
-| Parameter | Type                                                                       | Description |
-| --------- | -------------------------------------------------------------------------- | ----------- |
-| eventName | K                                                                          |             |
-| handler   | (event: [PageEventObject](./puppeteer.pageeventobject.md)\[K\]) =&gt; void |             |
-
-**Returns:**
-
-this

docs/api/puppeteer.pageevent.md

@@ -1,15 +1,15 @@
 ---
-sidebar_label: PageEmittedEvents
+sidebar_label: PageEvent
 ---
 
-# PageEmittedEvents enum
+# PageEvent enum
 
 All the events that a page instance may emit.
 
 #### Signature:
 
 ```typescript
-export declare const enum PageEmittedEvents
+export declare const enum PageEvent
 ```
 
 ## Enumeration Members

docs/api/puppeteer.pageevents.md

@@ -1,35 +1,37 @@
 ---
-sidebar_label: PageEventObject
+sidebar_label: PageEvents
 ---
 
-# PageEventObject interface
+# PageEvents interface
 
 Denotes the objects received by callback functions for page events.
 
-See [PageEmittedEvents](./puppeteer.pageemittedevents.md) for more detail on the events and when they are emitted.
+See [PageEvent](./puppeteer.pageevent.md) for more detail on the events and when they are emitted.
 
 #### Signature:
 
 ```typescript
-export interface PageEventObject
+export interface PageEvents extends Record<EventType, unknown>
 ```
 
+**Extends:** Record&lt;EventType, unknown&gt;
+
 ## Properties
 
 | Property               | Modifiers | Type                                                           | Description | Default |
 | ---------------------- | --------- | -------------------------------------------------------------- | ----------- | ------- |
-| close                  |           | never                                                          |             |         |
+| close                  |           | undefined                                                      |             |         |
 | console                |           | [ConsoleMessage](./puppeteer.consolemessage.md)                |             |         |
 | dialog                 |           | [Dialog](./puppeteer.dialog.md)                                |             |         |
-| domcontentloaded       |           | never                                                          |             |         |
+| domcontentloaded       |           | undefined                                                      |             |         |
 | error                  |           | Error                                                          |             |         |
 | frameattached          |           | [Frame](./puppeteer.frame.md)                                  |             |         |
 | framedetached          |           | [Frame](./puppeteer.frame.md)                                  |             |         |
 | framenavigated         |           | [Frame](./puppeteer.frame.md)                                  |             |         |
-| load                   |           | never                                                          |             |         |
+| load                   |           | undefined                                                      |             |         |
 | metrics                |           | { title: string; metrics: [Metrics](./puppeteer.metrics.md); } |             |         |
 | pageerror              |           | Error                                                          |             |         |
-| popup                  |           | [Page](./puppeteer.page.md)                                    |             |         |
+| popup                  |           | [Page](./puppeteer.page.md) \| null                            |             |         |
 | request                |           | [HTTPRequest](./puppeteer.httprequest.md)                      |             |         |
 | requestfailed          |           | [HTTPRequest](./puppeteer.httprequest.md)                      |             |         |
 | requestfinished        |           | [HTTPRequest](./puppeteer.httprequest.md)                      |             |         |

docs/api/puppeteer.webworker.md

@@ -9,10 +9,10 @@ This class represents a [WebWorker](https://developer.mozilla.org/en-US/docs/Web
 #### Signature:
 
 ```typescript
-export declare class WebWorker extends EventEmitter
+export declare class WebWorker extends EventEmitter<Record<EventType, unknown>>
 ```
 
-**Extends:** [EventEmitter](./puppeteer.eventemitter.md)
+**Extends:** [EventEmitter](./puppeteer.eventemitter.md)&lt;Record&lt;EventType, unknown&gt;&gt;
 
 ## Remarks
 

package-lock.json

@@ -3434,11 +3434,12 @@
       }
     },
     "node_modules/chromium-bidi": {
-      "version": "0.4.26",
+      "version": "0.4.27",
-      "resolved": "https://registry.npmjs.org/chromium-bidi/-/chromium-bidi-0.4.26.tgz",
+      "resolved": "https://registry.npmjs.org/chromium-bidi/-/chromium-bidi-0.4.27.tgz",
-      "integrity": "sha512-lukBGfogAI4T0y3acc86RaacqgKQve47/8pV2c+Hr1PjcICj2K4OkL3qfX3qrqxxnd4ddurFC0WBA3VCQqYeUQ==",
+      "integrity": "sha512-8Irq0FbKYN8Xmj8M62kta6wk5MyDKeYIFtNavxQ2M3xf2v5MCC4ntf+FxitQu1iHaQvGU6t5O+Nrep0RNNS0EQ==",
       "dependencies": {
-        "mitt": "3.0.1"
+        "mitt": "3.0.1",
+        "urlpattern-polyfill": "9.0.0"
       },
       "peerDependencies": {
         "devtools-protocol": "*"
@@ -10668,6 +10669,11 @@
         "punycode": "^2.1.0"
       }
     },
+    "node_modules/urlpattern-polyfill": {
+      "version": "9.0.0",
+      "resolved": "https://registry.npmjs.org/urlpattern-polyfill/-/urlpattern-polyfill-9.0.0.tgz",
+      "integrity": "sha512-WHN8KDQblxd32odxeIgo83rdVDE2bvdkb86it7bMhYZwWKJz0+O0RK/eZiHYnM+zgt/U7hAHOlCQGfjjvSkw2g=="
+    },
     "node_modules/util-deprecate": {
       "version": "1.0.2",
       "license": "MIT"
@@ -11108,7 +11114,7 @@
       "license": "Apache-2.0",
       "dependencies": {
         "@puppeteer/browsers": "1.7.1",
-        "chromium-bidi": "0.4.26",
+        "chromium-bidi": "0.4.27",
         "cross-fetch": "4.0.0",
         "debug": "4.3.4",
         "devtools-protocol": "0.0.1159816",
@@ -13450,11 +13456,12 @@
       "dev": true
     },
     "chromium-bidi": {
-      "version": "0.4.26",
+      "version": "0.4.27",
-      "resolved": "https://registry.npmjs.org/chromium-bidi/-/chromium-bidi-0.4.26.tgz",
+      "resolved": "https://registry.npmjs.org/chromium-bidi/-/chromium-bidi-0.4.27.tgz",
-      "integrity": "sha512-lukBGfogAI4T0y3acc86RaacqgKQve47/8pV2c+Hr1PjcICj2K4OkL3qfX3qrqxxnd4ddurFC0WBA3VCQqYeUQ==",
+      "integrity": "sha512-8Irq0FbKYN8Xmj8M62kta6wk5MyDKeYIFtNavxQ2M3xf2v5MCC4ntf+FxitQu1iHaQvGU6t5O+Nrep0RNNS0EQ==",
       "requires": {
-        "mitt": "3.0.1"
+        "mitt": "3.0.1",
+        "urlpattern-polyfill": "9.0.0"
       }
     },
     "ci-info": {
@@ -17241,7 +17248,7 @@
       "version": "file:packages/puppeteer-core",
       "requires": {
         "@puppeteer/browsers": "1.7.1",
-        "chromium-bidi": "0.4.26",
+        "chromium-bidi": "0.4.27",
         "cross-fetch": "4.0.0",
         "debug": "4.3.4",
         "devtools-protocol": "0.0.1159816",
@@ -18455,6 +18462,11 @@
         "punycode": "^2.1.0"
       }
     },
+    "urlpattern-polyfill": {
+      "version": "9.0.0",
+      "resolved": "https://registry.npmjs.org/urlpattern-polyfill/-/urlpattern-polyfill-9.0.0.tgz",
+      "integrity": "sha512-WHN8KDQblxd32odxeIgo83rdVDE2bvdkb86it7bMhYZwWKJz0+O0RK/eZiHYnM+zgt/U7hAHOlCQGfjjvSkw2g=="
+    },
     "util-deprecate": {
       "version": "1.0.2"
     },

packages/puppeteer-core/package.json

@@ -141,7 +141,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@puppeteer/browsers": "1.7.1",
-    "chromium-bidi": "0.4.26",
+    "chromium-bidi": "0.4.27",
     "cross-fetch": "4.0.0",
     "debug": "4.3.4",
     "devtools-protocol": "0.0.1159816",

packages/puppeteer-core/src/api/Browser.ts

@@ -21,7 +21,7 @@ import {ChildProcess} from 'child_process';
 import {Protocol} from 'devtools-protocol';
 
 import {Symbol} from '../../third_party/disposablestack/disposablestack.js';
-import {EventEmitter} from '../common/EventEmitter.js';
+import {EventEmitter, EventType} from '../common/EventEmitter.js';
 import {debugError, waitWithTimeout} from '../common/util.js';
 import {Deferred} from '../util/Deferred.js';
 
@@ -130,7 +130,7 @@ export interface WaitForTargetOptions {
  *
  * @public
  */
-export const enum BrowserEmittedEvents {
+export const enum BrowserEvent {
   /**
    * Emitted when Puppeteer gets disconnected from the browser instance. This
    * might happen because of one of the following:
@@ -140,7 +140,6 @@ export const enum BrowserEmittedEvents {
    * - The {@link Browser.disconnect | browser.disconnect } method was called.
    */
   Disconnected = 'disconnected',
-
   /**
    * Emitted when the url of a target changes. Contains a {@link Target} instance.
    *
@@ -149,7 +148,6 @@ export const enum BrowserEmittedEvents {
    * Note that this includes target changes in incognito browser contexts.
    */
   TargetChanged = 'targetchanged',
-
   /**
    * Emitted when a target is created, for example when a new page is opened by
    * {@link https://developer.mozilla.org/en-US/docs/Web/API/Window/open | window.open}
@@ -171,6 +169,31 @@ export const enum BrowserEmittedEvents {
    * Note that this includes target destructions in incognito browser contexts.
    */
   TargetDestroyed = 'targetdestroyed',
+  /**
+   * @internal
+   */
+  TargetDiscovered = 'targetdiscovered',
+}
+
+export {
+  /**
+   * @deprecated Use {@link BrowserEvent}.
+   */
+  BrowserEvent as BrowserEmittedEvents,
+};
+
+/**
+ * @public
+ */
+export interface BrowserEvents extends Record<EventType, unknown> {
+  [BrowserEvent.Disconnected]: undefined;
+  [BrowserEvent.TargetCreated]: Target;
+  [BrowserEvent.TargetDestroyed]: Target;
+  [BrowserEvent.TargetChanged]: Target;
+  /**
+   * @internal
+   */
+  [BrowserEvent.TargetDiscovered]: Protocol.Target.TargetInfo;
 }
 
 /**
@@ -180,7 +203,7 @@ export const enum BrowserEmittedEvents {
  * @remarks
  *
  * The Browser class extends from Puppeteer's {@link EventEmitter} class and will
- * emit various events which are documented in the {@link BrowserEmittedEvents} enum.
+ * emit various events which are documented in the {@link BrowserEvent} enum.
  *
  * @example
  * An example of using a {@link Browser} to create a {@link Page}:
@@ -219,7 +242,7 @@ export const enum BrowserEmittedEvents {
  * @public
  */
 export class Browser
-  extends EventEmitter
+  extends EventEmitter<BrowserEvents>
   implements AsyncDisposable, Disposable
 {
   /**
@@ -389,8 +412,8 @@ export class Browser
     const {timeout = 30000} = options;
     const targetDeferred = Deferred.create<Target | PromiseLike<Target>>();
 
-    this.on(BrowserEmittedEvents.TargetCreated, check);
+    this.on(BrowserEvent.TargetCreated, check);
-    this.on(BrowserEmittedEvents.TargetChanged, check);
+    this.on(BrowserEvent.TargetChanged, check);
     try {
       this.targets().forEach(check);
       if (!timeout) {
@@ -402,8 +425,8 @@ export class Browser
         timeout
       );
     } finally {
-      this.off(BrowserEmittedEvents.TargetCreated, check);
+      this.off(BrowserEvent.TargetCreated, check);
-      this.off(BrowserEmittedEvents.TargetChanged, check);
+      this.off(BrowserEvent.TargetChanged, check);
     }
 
     async function check(target: Target): Promise<void> {
@@ -491,28 +514,3 @@ export class Browser
     return this.close();
   }
 }
-/**
- * @public
- */
-export const enum BrowserContextEmittedEvents {
-  /**
-   * Emitted when the url of a target inside the browser context changes.
-   * Contains a {@link Target} instance.
-   */
-  TargetChanged = 'targetchanged',
-
-  /**
-   * Emitted when a target is created within the browser context, for example
-   * when a new page is opened by
-   * {@link https://developer.mozilla.org/en-US/docs/Web/API/Window/open | window.open}
-   * or by {@link BrowserContext.newPage | browserContext.newPage}
-   *
-   * Contains a {@link Target} instance.
-   */
-  TargetCreated = 'targetcreated',
-  /**
-   * Emitted when a target is destroyed within the browser context, for example
-   * when a page is closed. Contains a {@link Target} instance.
-   */
-  TargetDestroyed = 'targetdestroyed',
-}

packages/puppeteer-core/src/api/BrowserContext.ts

@@ -14,12 +14,54 @@
  * limitations under the License.
  */
 
-import {EventEmitter} from '../common/EventEmitter.js';
+import {EventEmitter, EventType} from '../common/EventEmitter.js';
 
-import type {Permission, Browser} from './Browser.js';
+import type {Browser, Permission} from './Browser.js';
 import {Page} from './Page.js';
 import type {Target} from './Target.js';
 
+/**
+ * @public
+ */
+export const enum BrowserContextEvent {
+  /**
+   * Emitted when the url of a target inside the browser context changes.
+   * Contains a {@link Target} instance.
+   */
+  TargetChanged = 'targetchanged',
+
+  /**
+   * Emitted when a target is created within the browser context, for example
+   * when a new page is opened by
+   * {@link https://developer.mozilla.org/en-US/docs/Web/API/Window/open | window.open}
+   * or by {@link BrowserContext.newPage | browserContext.newPage}
+   *
+   * Contains a {@link Target} instance.
+   */
+  TargetCreated = 'targetcreated',
+  /**
+   * Emitted when a target is destroyed within the browser context, for example
+   * when a page is closed. Contains a {@link Target} instance.
+   */
+  TargetDestroyed = 'targetdestroyed',
+}
+
+export {
+  /**
+   * @deprecated Use {@link BrowserContextEvent}
+   */
+  BrowserContextEvent as BrowserContextEmittedEvents,
+};
+
+/**
+ * @public
+ */
+export interface BrowserContextEvents extends Record<EventType, unknown> {
+  [BrowserContextEvent.TargetChanged]: Target;
+  [BrowserContextEvent.TargetCreated]: Target;
+  [BrowserContextEvent.TargetDestroyed]: Target;
+}
+
 /**
  * BrowserContexts provide a way to operate multiple independent browser
  * sessions. When a browser is launched, it has a single BrowserContext used by
@@ -30,7 +72,7 @@ import type {Target} from './Target.js';
  *
  * The Browser class extends from Puppeteer's {@link EventEmitter} class and
  * will emit various events which are documented in the
- * {@link BrowserContextEmittedEvents} enum.
+ * {@link BrowserContextEvents} enum.
  *
  * If a page opens another page, e.g. with a `window.open` call, the popup will
  * belong to the parent page's browser context.
@@ -55,7 +97,7 @@ import type {Target} from './Target.js';
  * @public
  */
 
-export class BrowserContext extends EventEmitter {
+export class BrowserContext extends EventEmitter<BrowserContextEvents> {
   /**
    * @internal
    */

packages/puppeteer-core/src/api/CDPSession.ts

@@ -0,0 +1,122 @@
+import type {ProtocolMapping} from 'devtools-protocol/types/protocol-mapping.js';
+
+import type {Connection} from '../common/Connection.js';
+import {EventEmitter, EventType} from '../common/EventEmitter.js';
+
+/**
+ * @public
+ */
+export type CDPEvents = {
+  [Property in keyof ProtocolMapping.Events]: ProtocolMapping.Events[Property][0];
+};
+
+/**
+ * Internal events that the CDPSession class emits.
+ *
+ * @internal
+ */
+// eslint-disable-next-line @typescript-eslint/no-namespace
+export namespace CDPSessionEvent {
+  export const Disconnected = Symbol('CDPSession.Disconnected');
+  export const Swapped = Symbol('CDPSession.Swapped');
+  /**
+   * Emitted when the session is ready to be configured during the auto-attach
+   * process. Right after the event is handled, the session will be resumed.
+   */
+  export const Ready = Symbol('CDPSession.Ready');
+  export const SessionAttached = Symbol('CDPSession.SessionAttached');
+  export const SessionDetached = Symbol('CDPSession.SessionDetached');
+}
+
+/**
+ * @public
+ */
+export interface CDPSessionEvents
+  extends CDPEvents,
+    Record<EventType, unknown> {
+  /** @internal */
+  [CDPSessionEvent.Disconnected]: undefined;
+  /** @internal */
+  [CDPSessionEvent.Swapped]: CDPSession;
+  /** @internal */
+  [CDPSessionEvent.Ready]: CDPSession;
+  /** @internal */
+  [CDPSessionEvent.SessionAttached]: CDPSession;
+  /** @internal */
+  [CDPSessionEvent.SessionDetached]: CDPSession;
+}
+
+/**
+ * The `CDPSession` instances are used to talk raw Chrome Devtools Protocol.
+ *
+ * @remarks
+ *
+ * Protocol methods can be called with {@link CDPSession.send} method and protocol
+ * events can be subscribed to with `CDPSession.on` method.
+ *
+ * Useful links: {@link https://chromedevtools.github.io/devtools-protocol/ | DevTools Protocol Viewer}
+ * and {@link https://github.com/aslushnikov/getting-started-with-cdp/blob/HEAD/README.md | Getting Started with DevTools Protocol}.
+ *
+ * @example
+ *
+ * ```ts
+ * const client = await page.target().createCDPSession();
+ * await client.send('Animation.enable');
+ * client.on('Animation.animationCreated', () =>
+ *   console.log('Animation created!')
+ * );
+ * const response = await client.send('Animation.getPlaybackRate');
+ * console.log('playback rate is ' + response.playbackRate);
+ * await client.send('Animation.setPlaybackRate', {
+ *   playbackRate: response.playbackRate / 2,
+ * });
+ * ```
+ *
+ * @public
+ */
+export abstract class CDPSession extends EventEmitter<CDPSessionEvents> {
+  /**
+   * @internal
+   */
+  constructor() {
+    super();
+  }
+
+  connection(): Connection | undefined {
+    throw new Error('Not implemented');
+  }
+
+  /**
+   * Parent session in terms of CDP's auto-attach mechanism.
+   *
+   * @internal
+   */
+  parentSession(): CDPSession | undefined {
+    return undefined;
+  }
+
+  send<T extends keyof ProtocolMapping.Commands>(
+    method: T,
+    ...paramArgs: ProtocolMapping.Commands[T]['paramsType']
+  ): Promise<ProtocolMapping.Commands[T]['returnType']>;
+  send<T extends keyof ProtocolMapping.Commands>(): Promise<
+    ProtocolMapping.Commands[T]['returnType']
+  > {
+    throw new Error('Not implemented');
+  }
+
+  /**
+   * Detaches the cdpSession from the target. Once detached, the cdpSession object
+   * won't emit any events and can't be used to send messages.
+   */
+  async detach(): Promise<void> {
+    throw new Error('Not implemented');
+  }
+
+  /**
+   * Returns the session's id.
+   */
+  id(): string {
+    throw new Error('Not implemented');
+  }
+}

packages/puppeteer-core/src/api/Environment.ts

@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-import {CDPSession} from '../common/Connection.js';
+import {CDPSession} from './CDPSession.js';
-
 import {Realm} from './Realm.js';
 
 /**

packages/puppeteer-core/src/api/Frame.ts

@@ -14,12 +14,13 @@
  * limitations under the License.
  */
 
+import Protocol from 'devtools-protocol';
+
 import {ClickOptions, ElementHandle} from '../api/ElementHandle.js';
 import {HTTPResponse} from '../api/HTTPResponse.js';
 import {Page, WaitTimeoutOptions} from '../api/Page.js';
-import {CDPSession} from '../common/Connection.js';
 import {DeviceRequestPrompt} from '../common/DeviceRequestPrompt.js';
-import {EventEmitter} from '../common/EventEmitter.js';
+import {EventEmitter, EventType} from '../common/EventEmitter.js';
 import {getQueryHandlerAndSelector} from '../common/GetQueryHandler.js';
 import {transposeIterableHandle} from '../common/HandleIterator.js';
 import {
@@ -43,6 +44,7 @@ import {
 import {assert} from '../util/assert.js';
 import {throwIfDisposed} from '../util/decorators.js';
 
+import {CDPSession} from './CDPSession.js';
 import {KeyboardTypeOptions} from './Input.js';
 import {FunctionLocator, Locator, NodeLocator} from './locators/locators.js';
 import {Realm} from './Realm.js';
@@ -127,6 +129,44 @@ export interface FrameAddStyleTagOptions {
   content?: string;
 }
 
+/**
+ * @public
+ */
+export interface FrameEvents extends Record<EventType, unknown> {
+  /** @internal */
+  [FrameEvent.FrameNavigated]: Protocol.Page.NavigationType;
+  /** @internal */
+  [FrameEvent.FrameSwapped]: undefined;
+  /** @internal */
+  [FrameEvent.LifecycleEvent]: undefined;
+  /** @internal */
+  [FrameEvent.FrameNavigatedWithinDocument]: undefined;
+  /** @internal */
+  [FrameEvent.FrameDetached]: Frame;
+  /** @internal */
+  [FrameEvent.FrameSwappedByActivation]: undefined;
+}
+
+/**
+ * We use symbols to prevent external parties listening to these events.
+ * They are internal to Puppeteer.
+ *
+ * @internal
+ */
+// eslint-disable-next-line @typescript-eslint/no-namespace
+export namespace FrameEvent {
+  export const FrameNavigated = Symbol('Frame.FrameNavigated');
+  export const FrameSwapped = Symbol('Frame.FrameSwapped');
+  export const LifecycleEvent = Symbol('Frame.LifecycleEvent');
+  export const FrameNavigatedWithinDocument = Symbol(
+    'Frame.FrameNavigatedWithinDocument'
+  );
+  export const FrameDetached = Symbol('Frame.FrameDetached');
+  export const FrameSwappedByActivation = Symbol(
+    'Frame.FrameSwappedByActivation'
+  );
+}
+
 /**
  * @internal
  */
@@ -181,13 +221,13 @@ export const throwIfDetached = throwIfDisposed<Frame>(frame => {
  * Frame lifecycles are controlled by three events that are all dispatched on
  * the parent {@link Frame.page | page}:
  *
- * - {@link PageEmittedEvents.FrameAttached}
+ * - {@link PageEvent.FrameAttached}
- * - {@link PageEmittedEvents.FrameNavigated}
+ * - {@link PageEvent.FrameNavigated}
- * - {@link PageEmittedEvents.FrameDetached}
+ * - {@link PageEvent.FrameDetached}
  *
  * @public
  */
-export abstract class Frame extends EventEmitter {
+export abstract class Frame extends EventEmitter<FrameEvents> {
   /**
    * @internal
    */

packages/puppeteer-core/src/api/HTTPRequest.ts

@@ -15,8 +15,7 @@
  */
 import {Protocol} from 'devtools-protocol';
 
-import {CDPSession} from '../common/Connection.js';
+import {CDPSession} from './CDPSession.js';
-
 import {Frame} from './Frame.js';
 import {HTTPResponse} from './HTTPResponse.js';
 

packages/puppeteer-core/src/api/Page.ts

@@ -19,6 +19,8 @@ import type {Readable} from 'stream';
 import {Protocol} from 'devtools-protocol';
 
 import {
+  delay,
+  filter,
   filterAsync,
   first,
   firstValueFrom,
@@ -27,30 +29,34 @@ import {
   map,
   merge,
   Observable,
-  raceWith,
-  delay,
-  filter,
   of,
-  switchMap,
+  raceWith,
   startWith,
+  switchMap,
 } from '../../third_party/rxjs/rxjs.js';
 import type {HTTPRequest} from '../api/HTTPRequest.js';
 import type {HTTPResponse} from '../api/HTTPResponse.js';
 import type {Accessibility} from '../common/Accessibility.js';
-import type {CDPSession} from '../common/Connection.js';
+import type {BidiNetworkManager} from '../common/bidi/NetworkManager.js';
 import type {ConsoleMessage} from '../common/ConsoleMessage.js';
 import type {Coverage} from '../common/Coverage.js';
 import {Device} from '../common/Device.js';
 import {DeviceRequestPrompt} from '../common/DeviceRequestPrompt.js';
 import {TargetCloseError} from '../common/Errors.js';
-import {EventEmitter, Handler} from '../common/EventEmitter.js';
+import {
+  EventEmitter,
+  EventsWithWildcard,
+  EventType,
+  Handler,
+} from '../common/EventEmitter.js';
 import type {FileChooser} from '../common/FileChooser.js';
 import type {WaitForSelectorOptions} from '../common/IsolatedWorld.js';
 import type {PuppeteerLifeCycleEvent} from '../common/LifecycleWatcher.js';
 import {
+  NetworkManager as CdpNetworkManager,
   Credentials,
   NetworkConditions,
-  NetworkManagerEmittedEvents,
+  NetworkManagerEvent,
 } from '../common/NetworkManager.js';
 import {
   LowerCasePaperFormat,
@@ -81,6 +87,7 @@ import {Deferred} from '../util/Deferred.js';
 
 import type {Browser} from './Browser.js';
 import type {BrowserContext} from './BrowserContext.js';
+import type {CDPSession} from './CDPSession.js';
 import type {Dialog} from './Dialog.js';
 import type {ClickOptions, ElementHandle} from './ElementHandle.js';
 import type {
@@ -249,7 +256,7 @@ export interface ScreenshotOptions {
  *
  * @public
  */
-export const enum PageEmittedEvents {
+export const enum PageEvent {
   /**
    * Emitted when the page closes.
    */
@@ -396,36 +403,52 @@ export const enum PageEmittedEvents {
   WorkerDestroyed = 'workerdestroyed',
 }
 
+export {
+  /**
+   * All the events that a page instance may emit.
+   *
+   * @deprecated Use {@link PageEvent}.
+   */
+  PageEvent as PageEmittedEvents,
+};
+
 /**
  * Denotes the objects received by callback functions for page events.
  *
- * See {@link PageEmittedEvents} for more detail on the events and when they are
+ * See {@link PageEvent} for more detail on the events and when they are
  * emitted.
  *
  * @public
  */
-export interface PageEventObject {
+export interface PageEvents extends Record<EventType, unknown> {
-  close: never;
+  [PageEvent.Close]: undefined;
-  console: ConsoleMessage;
+  [PageEvent.Console]: ConsoleMessage;
-  dialog: Dialog;
+  [PageEvent.Dialog]: Dialog;
-  domcontentloaded: never;
+  [PageEvent.DOMContentLoaded]: undefined;
-  error: Error;
+  [PageEvent.Error]: Error;
-  frameattached: Frame;
+  [PageEvent.FrameAttached]: Frame;
-  framedetached: Frame;
+  [PageEvent.FrameDetached]: Frame;
-  framenavigated: Frame;
+  [PageEvent.FrameNavigated]: Frame;
-  load: never;
+  [PageEvent.Load]: undefined;
-  metrics: {title: string; metrics: Metrics};
+  [PageEvent.Metrics]: {title: string; metrics: Metrics};
-  pageerror: Error;
+  [PageEvent.PageError]: Error;
-  popup: Page;
+  [PageEvent.Popup]: Page | null;
-  request: HTTPRequest;
+  [PageEvent.Request]: HTTPRequest;
-  response: HTTPResponse;
+  [PageEvent.Response]: HTTPResponse;
-  requestfailed: HTTPRequest;
+  [PageEvent.RequestFailed]: HTTPRequest;
-  requestfinished: HTTPRequest;
+  [PageEvent.RequestFinished]: HTTPRequest;
-  requestservedfromcache: HTTPRequest;
+  [PageEvent.RequestServedFromCache]: HTTPRequest;
-  workercreated: WebWorker;
+  [PageEvent.WorkerCreated]: WebWorker;
-  workerdestroyed: WebWorker;
+  [PageEvent.WorkerDestroyed]: WebWorker;
 }
 
+export {
+  /**
+   * @deprecated Use {@link PageEvents}.
+   */
+  PageEvents as PageEventObject,
+};
+
 /**
  * @public
  */
@@ -460,7 +483,7 @@ export interface NewDocumentScriptEvaluation {
  * ```
  *
  * The Page class extends from Puppeteer's {@link EventEmitter} class and will
- * emit various events which are documented in the {@link PageEmittedEvents} enum.
+ * emit various events which are documented in the {@link PageEvent} enum.
  *
  * @example
  * This example logs a message for a single page `load` event:
@@ -469,7 +492,7 @@ export interface NewDocumentScriptEvaluation {
  * page.once('load', () => console.log('Page loaded!'));
  * ```
  *
- * To unsubscribe from events use the {@link Page.off} method:
+ * To unsubscribe from events use the {@link EventEmitter.off} method:
  *
  * ```ts
  * function logRequest(interceptedRequest) {
@@ -483,10 +506,10 @@ export interface NewDocumentScriptEvaluation {
  * @public
  */
 export abstract class Page
-  extends EventEmitter
+  extends EventEmitter<PageEvents>
   implements AsyncDisposable, Disposable
 {
-  #handlerMap = new WeakMap<Handler<any>, Handler<any>>();
+  #requestHandlers = new WeakMap<Handler<HTTPRequest>, Handler<HTTPRequest>>();
 
   /**
    * @internal
@@ -519,52 +542,56 @@ export abstract class Page
   /**
    * Listen to page events.
    *
-   * :::note
+   * @remarks
-   *
    * This method exists to define event typings and handle proper wireup of
    * cooperative request interception. Actual event listening and dispatching is
    * delegated to {@link EventEmitter}.
    *
-   * :::
+   * @internal
    */
-  override on<K extends keyof PageEventObject>(
+  override on<K extends keyof EventsWithWildcard<PageEvents>>(
-    eventName: K,
+    type: K,
-    handler: (event: PageEventObject[K]) => void
+    handler: (event: EventsWithWildcard<PageEvents>[K]) => void
   ): this {
-    if (eventName === 'request') {
+    if (type !== PageEvent.Request) {
-      const wrap =
+      return super.on(type, handler);
-        this.#handlerMap.get(handler) ||
+    }
-        ((event: HTTPRequest) => {
+    let wrapper = this.#requestHandlers.get(
+      handler as (event: PageEvents[PageEvent.Request]) => void
+    );
+    if (wrapper === undefined) {
+      wrapper = (event: HTTPRequest) => {
         event.enqueueInterceptAction(() => {
-            return handler(event as PageEventObject[K]);
+          return handler(event as EventsWithWildcard<PageEvents>[K]);
         });
-        });
+      };
-
+      this.#requestHandlers.set(
-      this.#handlerMap.set(handler, wrap);
+        handler as (event: PageEvents[PageEvent.Request]) => void,
-
+        wrapper
-      return super.on(eventName, wrap);
+      );
     }
-    return super.on(eventName, handler);
+    return super.on(
+      type,
+      wrapper as (event: EventsWithWildcard<PageEvents>[K]) => void
+    );
   }
 
-  override once<K extends keyof PageEventObject>(
+  /**
-    eventName: K,
+   * @internal
-    handler: (event: PageEventObject[K]) => void
+   */
+  override off<K extends keyof EventsWithWildcard<PageEvents>>(
+    type: K,
+    handler: (event: EventsWithWildcard<PageEvents>[K]) => void
   ): this {
-    // Note: this method only exists to define the types; we delegate the impl
+    if (type === PageEvent.Request) {
-    // to EventEmitter.
+      handler =
-    return super.once(eventName, handler);
+        (this.#requestHandlers.get(
+          handler as (
+            event: EventsWithWildcard<PageEvents>[PageEvent.Request]
+          ) => void
+        ) as (event: EventsWithWildcard<PageEvents>[K]) => void) || handler;
     }
-
+    return super.off(type, handler);
-  override off<K extends keyof PageEventObject>(
-    eventName: K,
-    handler: (event: PageEventObject[K]) => void
-  ): this {
-    if (eventName === 'request') {
-      handler = this.#handlerMap.get(handler) || handler;
-    }
-
-    return super.off(eventName, handler);
   }
 
   /**
@@ -1696,9 +1723,7 @@ export abstract class Page
    * @internal
    */
   protected async _waitForNetworkIdle(
-    networkManager: EventEmitter & {
+    networkManager: BidiNetworkManager | CdpNetworkManager,
-      inFlightRequestsCount: () => number;
-    },
     idleTime: number,
     ms: number,
     closedDeferred: Deferred<TargetCloseError>
@@ -1707,15 +1732,15 @@ export abstract class Page
       merge(
         fromEvent(
           networkManager,
-          NetworkManagerEmittedEvents.Request as unknown as string
+          NetworkManagerEvent.Request as unknown as string
         ),
         fromEvent(
           networkManager,
-          NetworkManagerEmittedEvents.Response as unknown as string
+          NetworkManagerEvent.Response as unknown as string
         ),
         fromEvent(
           networkManager,
-          NetworkManagerEmittedEvents.RequestFailed as unknown as string
+          NetworkManagerEvent.RequestFailed as unknown as string
         )
       ).pipe(
         startWith(null),
@@ -1755,15 +1780,15 @@ export abstract class Page
 
     return await firstValueFrom(
       merge(
-        fromEvent(this, PageEmittedEvents.FrameAttached) as Observable<Frame>,
+        fromEvent(this, PageEvent.FrameAttached) as Observable<Frame>,
-        fromEvent(this, PageEmittedEvents.FrameNavigated) as Observable<Frame>,
+        fromEvent(this, PageEvent.FrameNavigated) as Observable<Frame>,
         from(this.frames())
       ).pipe(
         filterAsync(urlOrPredicate),
         first(),
         raceWith(
           timeout(ms),
-          fromEvent(this, PageEmittedEvents.Close).pipe(
+          fromEvent(this, PageEvent.Close).pipe(
             map(() => {
               throw new TargetCloseError('Page closed.');
             })

packages/puppeteer-core/src/api/Target.ts

@@ -17,9 +17,10 @@
 import type {Browser} from '../api/Browser.js';
 import type {BrowserContext} from '../api/BrowserContext.js';
 import {Page} from '../api/Page.js';
-import {CDPSession} from '../common/Connection.js';
 import {WebWorker} from '../common/WebWorker.js';
 
+import {CDPSession} from './CDPSession.js';
+
 /**
  * @public
  */

packages/puppeteer-core/src/api/api.ts

@@ -28,3 +28,4 @@ export * from './locators/locators.js';
 export * from './Page.js';
 export * from './Realm.js';
 export * from './Target.js';
+export * from './CDPSession.js';

packages/puppeteer-core/src/api/locators/Locator.ts

@@ -37,7 +37,7 @@ import {
   retry,
   tap,
 } from '../../../third_party/rxjs/rxjs.js';
-import {EventEmitter} from '../../common/EventEmitter.js';
+import {EventEmitter, EventType} from '../../common/EventEmitter.js';
 import {HandleFor} from '../../common/types.js';
 import {debugError, timeout} from '../../common/util.js';
 import {BoundingBox, ClickOptions, ElementHandle} from '../ElementHandle.js';
@@ -130,20 +130,34 @@ export interface LocatorScrollOptions extends ActionOptions {
  *
  * @public
  */
-export enum LocatorEmittedEvents {
+export enum LocatorEvent {
   /**
    * Emitted every time before the locator performs an action on the located element(s).
    */
   Action = 'action',
 }
 
+export {
+  /**
+   * @deprecated Use {@link LocatorEvent}.
+   */
+  LocatorEvent as LocatorEmittedEvents,
+};
+
 /**
  * @public
  */
-export interface LocatorEventObject {
+export interface LocatorEvents extends Record<EventType, unknown> {
-  [LocatorEmittedEvents.Action]: never;
+  [LocatorEvent.Action]: undefined;
 }
 
+export {
+  /**
+   * @deprecated Use {@link LocatorEvents}.
+   */
+  LocatorEvents as LocatorEventObject,
+};
+
 /**
  * Locators describe a strategy of locating objects and performing an action on
  * them. If the action fails because the object is not ready for the action, the
@@ -152,7 +166,7 @@ export interface LocatorEventObject {
  *
  * @public
  */
-export abstract class Locator<T> extends EventEmitter {
+export abstract class Locator<T> extends EventEmitter<LocatorEvents> {
   /**
    * Creates a race between multiple locators but ensures that only a single one
    * acts.
@@ -224,27 +238,6 @@ export abstract class Locator<T> extends EventEmitter {
     return this._timeout;
   }
 
-  override on<K extends keyof LocatorEventObject>(
-    eventName: K,
-    handler: (event: LocatorEventObject[K]) => void
-  ): this {
-    return super.on(eventName, handler);
-  }
-
-  override once<K extends keyof LocatorEventObject>(
-    eventName: K,
-    handler: (event: LocatorEventObject[K]) => void
-  ): this {
-    return super.once(eventName, handler);
-  }
-
-  override off<K extends keyof LocatorEventObject>(
-    eventName: K,
-    handler: (event: LocatorEventObject[K]) => void
-  ): this {
-    return super.off(eventName, handler);
-  }
-
   setTimeout(timeout: number): Locator<T> {
     const locator = this._clone();
     locator._timeout = timeout;
@@ -426,7 +419,7 @@ export abstract class Locator<T> extends EventEmitter {
         signal
       ),
       tap(() => {
-        return this.emit(LocatorEmittedEvents.Action);
+        return this.emit(LocatorEvent.Action, undefined);
       }),
       mergeMap(handle => {
         return from(handle.click(options)).pipe(
@@ -456,7 +449,7 @@ export abstract class Locator<T> extends EventEmitter {
         signal
       ),
       tap(() => {
-        return this.emit(LocatorEmittedEvents.Action);
+        return this.emit(LocatorEvent.Action, undefined);
       }),
       mergeMap(handle => {
         return from(
@@ -587,7 +580,7 @@ export abstract class Locator<T> extends EventEmitter {
         signal
       ),
       tap(() => {
-        return this.emit(LocatorEmittedEvents.Action);
+        return this.emit(LocatorEvent.Action, undefined);
       }),
       mergeMap(handle => {
         return from(handle.hover()).pipe(
@@ -615,7 +608,7 @@ export abstract class Locator<T> extends EventEmitter {
         signal
       ),
       tap(() => {
-        return this.emit(LocatorEmittedEvents.Action);
+        return this.emit(LocatorEvent.Action, undefined);
       }),
       mergeMap(handle => {
         return from(

packages/puppeteer-core/src/common/Accessibility.ts

@@ -16,10 +16,9 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {ElementHandle} from '../api/ElementHandle.js';
 
-import {CDPSession} from './Connection.js';
-
 /**
  * Represents a Node and the properties of it that are relevant to Accessibility.
  * @public

packages/puppeteer-core/src/common/AriaQueryHandler.ts

@@ -16,11 +16,11 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {ElementHandle} from '../api/ElementHandle.js';
 import {assert} from '../util/assert.js';
 import {AsyncIterableUtil} from '../util/AsyncIterableUtil.js';
 
-import {CDPSession} from './Connection.js';
 import {IsolatedWorld} from './IsolatedWorld.js';
 import {QueryHandler, QuerySelector} from './QueryHandler.js';
 import {AwaitableIterable} from './types.js';

packages/puppeteer-core/src/common/Browser.ts

@@ -21,33 +21,33 @@ import {Protocol} from 'devtools-protocol';
 import {
   Browser as BrowserBase,
   BrowserCloseCallback,
-  TargetFilterCallback,
-  IsPageTargetCallback,
-  BrowserEmittedEvents,
-  BrowserContextEmittedEvents,
   BrowserContextOptions,
-  WEB_PERMISSION_TO_PROTOCOL_PERMISSION,
+  BrowserEvent,
+  IsPageTargetCallback,
   Permission,
+  TargetFilterCallback,
+  WEB_PERMISSION_TO_PROTOCOL_PERMISSION,
 } from '../api/Browser.js';
-import {BrowserContext} from '../api/BrowserContext.js';
+import {BrowserContext, BrowserContextEvent} from '../api/BrowserContext.js';
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
 import {Page} from '../api/Page.js';
 import {Target} from '../api/Target.js';
 import {USE_TAB_TARGET} from '../environment.js';
 import {assert} from '../util/assert.js';
 
 import {ChromeTargetManager} from './ChromeTargetManager.js';
-import {CDPSession, Connection, ConnectionEmittedEvents} from './Connection.js';
+import {Connection} from './Connection.js';
 import {FirefoxTargetManager} from './FirefoxTargetManager.js';
 import {Viewport} from './PuppeteerViewport.js';
 import {
+  CDPTarget,
+  DevToolsTarget,
   InitializationStatus,
   OtherTarget,
   PageTarget,
-  CDPTarget,
   WorkerTarget,
-  DevToolsTarget,
 } from './Target.js';
-import {TargetManager, TargetManagerEmittedEvents} from './TargetManager.js';
+import {TargetManager, TargetManagerEvent} from './TargetManager.js';
 import {TaskQueue} from './TaskQueue.js';
 
 /**
@@ -151,52 +151,46 @@ export class CDPBrowser extends BrowserBase {
   }
 
   #emitDisconnected = () => {
-    this.emit(BrowserEmittedEvents.Disconnected);
+    this.emit(BrowserEvent.Disconnected, undefined);
   };
 
   override async _attach(): Promise<void> {
-    this.#connection.on(
+    this.#connection.on(CDPSessionEvent.Disconnected, this.#emitDisconnected);
-      ConnectionEmittedEvents.Disconnected,
-      this.#emitDisconnected
-    );
     this.#targetManager.on(
-      TargetManagerEmittedEvents.TargetAvailable,
+      TargetManagerEvent.TargetAvailable,
       this.#onAttachedToTarget
     );
     this.#targetManager.on(
-      TargetManagerEmittedEvents.TargetGone,
+      TargetManagerEvent.TargetGone,
       this.#onDetachedFromTarget
     );
     this.#targetManager.on(
-      TargetManagerEmittedEvents.TargetChanged,
+      TargetManagerEvent.TargetChanged,
       this.#onTargetChanged
     );
     this.#targetManager.on(
-      TargetManagerEmittedEvents.TargetDiscovered,
+      TargetManagerEvent.TargetDiscovered,
       this.#onTargetDiscovered
     );
     await this.#targetManager.initialize();
   }
 
   override _detach(): void {
-    this.#connection.off(
+    this.#connection.off(CDPSessionEvent.Disconnected, this.#emitDisconnected);
-      ConnectionEmittedEvents.Disconnected,
-      this.#emitDisconnected
-    );
     this.#targetManager.off(
-      TargetManagerEmittedEvents.TargetAvailable,
+      TargetManagerEvent.TargetAvailable,
       this.#onAttachedToTarget
     );
     this.#targetManager.off(
-      TargetManagerEmittedEvents.TargetGone,
+      TargetManagerEvent.TargetGone,
       this.#onDetachedFromTarget
     );
     this.#targetManager.off(
-      TargetManagerEmittedEvents.TargetChanged,
+      TargetManagerEvent.TargetChanged,
       this.#onTargetChanged
     );
     this.#targetManager.off(
-      TargetManagerEmittedEvents.TargetDiscovered,
+      TargetManagerEvent.TargetDiscovered,
       this.#onTargetDiscovered
     );
   }
@@ -367,10 +361,8 @@ export class CDPBrowser extends BrowserBase {
       (await target._initializedDeferred.valueOrThrow()) ===
       InitializationStatus.SUCCESS
     ) {
-      this.emit(BrowserEmittedEvents.TargetCreated, target);
+      this.emit(BrowserEvent.TargetCreated, target);
-      target
+      target.browserContext().emit(BrowserContextEvent.TargetCreated, target);
-        .browserContext()
-        .emit(BrowserContextEmittedEvents.TargetCreated, target);
     }
   };
 
@@ -381,22 +373,18 @@ export class CDPBrowser extends BrowserBase {
       (await target._initializedDeferred.valueOrThrow()) ===
       InitializationStatus.SUCCESS
     ) {
-      this.emit(BrowserEmittedEvents.TargetDestroyed, target);
+      this.emit(BrowserEvent.TargetDestroyed, target);
-      target
+      target.browserContext().emit(BrowserContextEvent.TargetDestroyed, target);
-        .browserContext()
-        .emit(BrowserContextEmittedEvents.TargetDestroyed, target);
     }
   };
 
   #onTargetChanged = ({target}: {target: CDPTarget}): void => {
-    this.emit(BrowserEmittedEvents.TargetChanged, target);
+    this.emit(BrowserEvent.TargetChanged, target);
-    target
+    target.browserContext().emit(BrowserContextEvent.TargetChanged, target);
-      .browserContext()
-      .emit(BrowserContextEmittedEvents.TargetChanged, target);
   };
 
   #onTargetDiscovered = (targetInfo: Protocol.Target.TargetInfo): void => {
-    this.emit('targetdiscovered', targetInfo);
+    this.emit(BrowserEvent.TargetDiscovered, targetInfo);
   };
 
   /**

packages/puppeteer-core/src/common/CDPSession.ts

@@ -0,0 +1,154 @@
+import {ProtocolMapping} from 'devtools-protocol/types/protocol-mapping.js';
+
+import {CDPEvents, CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
+import {assert} from '../util/assert.js';
+
+import {
+  CallbackRegistry,
+  Connection,
+  createProtocolErrorMessage,
+} from './Connection.js';
+import {TargetCloseError} from './Errors.js';
+import {CDPTarget} from './Target.js';
+
+/**
+ * @internal
+ */
+
+export class CDPCDPSession extends CDPSession {
+  #sessionId: string;
+  #targetType: string;
+  #callbacks = new CallbackRegistry();
+  #connection?: Connection;
+  #parentSessionId?: string;
+  #target?: CDPTarget;
+
+  /**
+   * @internal
+   */
+  constructor(
+    connection: Connection,
+    targetType: string,
+    sessionId: string,
+    parentSessionId: string | undefined
+  ) {
+    super();
+    this.#connection = connection;
+    this.#targetType = targetType;
+    this.#sessionId = sessionId;
+    this.#parentSessionId = parentSessionId;
+  }
+
+  /**
+   * Sets the CDPTarget associated with the session instance.
+   *
+   * @internal
+   */
+  _setTarget(target: CDPTarget): void {
+    this.#target = target;
+  }
+
+  /**
+   * Gets the CDPTarget associated with the session instance.
+   *
+   * @internal
+   */
+  _target(): CDPTarget {
+    assert(this.#target, 'Target must exist');
+    return this.#target;
+  }
+
+  override connection(): Connection | undefined {
+    return this.#connection;
+  }
+
+  override parentSession(): CDPSession | undefined {
+    if (!this.#parentSessionId) {
+      return;
+    }
+    const parent = this.#connection?.session(this.#parentSessionId);
+    return parent ?? undefined;
+  }
+
+  override send<T extends keyof ProtocolMapping.Commands>(
+    method: T,
+    ...paramArgs: ProtocolMapping.Commands[T]['paramsType']
+  ): Promise<ProtocolMapping.Commands[T]['returnType']> {
+    if (!this.#connection) {
+      return Promise.reject(
+        new TargetCloseError(
+          `Protocol error (${method}): Session closed. Most likely the ${
+            this.#targetType
+          } has been closed.`
+        )
+      );
+    }
+    // See the comment in Connection#send explaining why we do this.
+    const params = paramArgs.length ? paramArgs[0] : undefined;
+    return this.#connection._rawSend(
+      this.#callbacks,
+      method,
+      params,
+      this.#sessionId
+    );
+  }
+
+  /**
+   * @internal
+   */
+  _onMessage(object: {
+    id?: number;
+    method: keyof CDPEvents;
+    params: CDPEvents[keyof CDPEvents];
+    error: {message: string; data: any; code: number};
+    result?: any;
+  }): void {
+    if (object.id) {
+      if (object.error) {
+        this.#callbacks.reject(
+          object.id,
+          createProtocolErrorMessage(object),
+          object.error.message
+        );
+      } else {
+        this.#callbacks.resolve(object.id, object.result);
+      }
+    } else {
+      assert(!object.id);
+      this.emit(object.method, object.params);
+    }
+  }
+
+  /**
+   * Detaches the cdpSession from the target. Once detached, the cdpSession object
+   * won't emit any events and can't be used to send messages.
+   */
+  override async detach(): Promise<void> {
+    if (!this.#connection) {
+      throw new Error(
+        `Session already detached. Most likely the ${
+          this.#targetType
+        } has been closed.`
+      );
+    }
+    await this.#connection.send('Target.detachFromTarget', {
+      sessionId: this.#sessionId,
+    });
+  }
+
+  /**
+   * @internal
+   */
+  _onClosed(): void {
+    this.#callbacks.clear();
+    this.#connection = undefined;
+    this.emit(CDPSessionEvent.Disconnected, undefined);
+  }
+
+  /**
+   * Returns the session's id.
+   */
+  override id(): string {
+    return this.#sessionId;
+  }
+}

packages/puppeteer-core/src/common/ChromeTargetManager.ts

@@ -17,17 +17,19 @@
 import {Protocol} from 'devtools-protocol';
 
 import {TargetFilterCallback} from '../api/Browser.js';
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
 import {TargetType} from '../api/Target.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 
-import {CDPSession, CDPSessionEmittedEvents, Connection} from './Connection.js';
+import {Connection} from './Connection.js';
 import {EventEmitter} from './EventEmitter.js';
-import {InitializationStatus, CDPTarget} from './Target.js';
+import {CDPTarget, InitializationStatus} from './Target.js';
 import {
   TargetFactory,
   TargetManager,
-  TargetManagerEmittedEvents,
+  TargetManagerEvent,
+  TargetManagerEvents,
 } from './TargetManager.js';
 import {debugError} from './util.js';
 
@@ -49,7 +51,10 @@ function isPageTargetBecomingPrimary(
  *
  * @internal
  */
-export class ChromeTargetManager extends EventEmitter implements TargetManager {
+export class ChromeTargetManager
+  extends EventEmitter<TargetManagerEvents>
+  implements TargetManager
+{
   #connection: Connection;
   /**
    * Keeps track of the following events: 'Target.targetCreated',
@@ -81,7 +86,7 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
 
   #attachedToTargetListenersBySession = new WeakMap<
     CDPSession | Connection,
-    (event: Protocol.Target.AttachedToTargetEvent) => Promise<void>
+    (event: Protocol.Target.AttachedToTargetEvent) => void
   >();
   #detachedFromTargetListenersBySession = new WeakMap<
     CDPSession | Connection,
@@ -116,7 +121,10 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
     this.#connection.on('Target.targetCreated', this.#onTargetCreated);
     this.#connection.on('Target.targetDestroyed', this.#onTargetDestroyed);
     this.#connection.on('Target.targetInfoChanged', this.#onTargetInfoChanged);
-    this.#connection.on('sessiondetached', this.#onSessionDetached);
+    this.#connection.on(
+      CDPSessionEvent.SessionDetached,
+      this.#onSessionDetached
+    );
     this.#setupAttachmentListeners(this.#connection);
 
     this.#connection
@@ -176,7 +184,10 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
     this.#connection.off('Target.targetCreated', this.#onTargetCreated);
     this.#connection.off('Target.targetDestroyed', this.#onTargetDestroyed);
     this.#connection.off('Target.targetInfoChanged', this.#onTargetInfoChanged);
-    this.#connection.off('sessiondetached', this.#onSessionDetached);
+    this.#connection.off(
+      CDPSessionEvent.SessionDetached,
+      this.#onSessionDetached
+    );
 
     this.#removeAttachmentListeners(this.#connection);
   }
@@ -193,7 +204,7 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
 
   #setupAttachmentListeners(session: CDPSession | Connection): void {
     const listener = (event: Protocol.Target.AttachedToTargetEvent) => {
-      return this.#onAttachedToTarget(session, event);
+      void this.#onAttachedToTarget(session, event);
     };
     assert(!this.#attachedToTargetListenersBySession.has(session));
     this.#attachedToTargetListenersBySession.set(session, listener);
@@ -210,11 +221,9 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
   }
 
   #removeAttachmentListeners(session: CDPSession | Connection): void {
-    if (this.#attachedToTargetListenersBySession.has(session)) {
+    const listener = this.#attachedToTargetListenersBySession.get(session);
-      session.off(
+    if (listener) {
-        'Target.attachedToTarget',
+      session.off('Target.attachedToTarget', listener);
-        this.#attachedToTargetListenersBySession.get(session)!
-      );
       this.#attachedToTargetListenersBySession.delete(session);
     }
 
@@ -237,7 +246,7 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
       event.targetInfo
     );
 
-    this.emit(TargetManagerEmittedEvents.TargetDiscovered, event.targetInfo);
+    this.emit(TargetManagerEvent.TargetDiscovered, event.targetInfo);
 
     // The connection is already attached to the browser target implicitly,
     // therefore, no new CDPSession is created and we have special handling
@@ -263,9 +272,11 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
       // Special case for service workers: report TargetGone event when
       // the worker is destroyed.
       const target = this.#attachedTargetsByTargetId.get(event.targetId);
-      this.emit(TargetManagerEmittedEvents.TargetGone, target);
+      if (target) {
+        this.emit(TargetManagerEvent.TargetGone, target);
         this.#attachedTargetsByTargetId.delete(event.targetId);
       }
+    }
   };
 
   #onTargetInfoChanged = (event: Protocol.Target.TargetInfoChangedEvent) => {
@@ -301,14 +312,14 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
         session,
         'Target that is being activated is missing a CDPSession.'
       );
-      session.parentSession()?.emit(CDPSessionEmittedEvents.Swapped, session);
+      session.parentSession()?.emit(CDPSessionEvent.Swapped, session);
     }
 
     target._targetInfoChanged(event.targetInfo);
 
     if (wasInitialized && previousURL !== target.url()) {
-      this.emit(TargetManagerEmittedEvents.TargetChanged, {
+      this.emit(TargetManagerEvent.TargetChanged, {
-        target: target,
+        target,
         wasInitialized,
         previousURL,
       });
@@ -359,7 +370,7 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
       const target = this.#targetFactory(targetInfo);
       target._initialize();
       this.#attachedTargetsByTargetId.set(targetInfo.targetId, target);
-      this.emit(TargetManagerEmittedEvents.TargetAvailable, target);
+      this.emit(TargetManagerEvent.TargetAvailable, target);
       return;
     }
 
@@ -398,11 +409,15 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
       this.#attachedTargetsBySessionId.set(session.id(), target);
     }
 
-    parentSession.emit(CDPSessionEmittedEvents.Ready, session);
+    if (parentSession instanceof CDPSession) {
+      parentSession.emit(CDPSessionEvent.Ready, session);
+    } else {
+      parentSession.emit(CDPSessionEvent.Ready, session);
+    }
 
     this.#targetsIdsForInit.delete(target._targetId);
     if (!isExistingTarget && isTargetExposed(target)) {
-      this.emit(TargetManagerEmittedEvents.TargetAvailable, target);
+      this.emit(TargetManagerEvent.TargetAvailable, target);
     }
     this.#finishInitializationIfReady();
 
@@ -440,7 +455,7 @@ export class ChromeTargetManager extends EventEmitter implements TargetManager {
 
     this.#attachedTargetsByTargetId.delete(target._targetId);
     if (isTargetExposed(target)) {
-      this.emit(TargetManagerEmittedEvents.TargetGone, target);
+      this.emit(TargetManagerEvent.TargetGone, target);
     }
   };
 }

packages/puppeteer-core/src/common/Connection.ts

@@ -17,14 +17,18 @@
 import {Protocol} from 'devtools-protocol';
 import {ProtocolMapping} from 'devtools-protocol/types/protocol-mapping.js';
 
-import {assert} from '../util/assert.js';
+import {
+  CDPSession,
+  CDPSessionEvent,
+  CDPSessionEvents,
+} from '../api/CDPSession.js';
 import {Deferred} from '../util/Deferred.js';
 
+import {CDPCDPSession} from './CDPSession.js';
 import {ConnectionTransport} from './ConnectionTransport.js';
 import {debug} from './Debug.js';
-import {TargetCloseError, ProtocolError} from './Errors.js';
+import {ProtocolError, TargetCloseError} from './Errors.js';
 import {EventEmitter} from './EventEmitter.js';
-import {CDPTarget} from './Target.js';
 import {debugError} from './util.js';
 
 const debugProtocolSend = debug('puppeteer:protocol:SEND ►');
@@ -35,15 +39,6 @@ const debugProtocolReceive = debug('puppeteer:protocol:RECV ◀');
  */
 export {ConnectionTransport, ProtocolMapping};
 
-/**
- * Internal events that the Connection class emits.
- *
- * @internal
- */
-export const ConnectionEmittedEvents = {
-  Disconnected: Symbol('Connection.Disconnected'),
-} as const;
-
 /**
  * @internal
  */
@@ -200,12 +195,12 @@ export class CallbackRegistry {
 /**
  * @public
  */
-export class Connection extends EventEmitter {
+export class Connection extends EventEmitter<CDPSessionEvents> {
   #url: string;
   #transport: ConnectionTransport;
   #delay: number;
   #timeout: number;
-  #sessions = new Map<string, CDPSessionImpl>();
+  #sessions = new Map<string, CDPCDPSession>();
   #closed = false;
   #manuallyAttached = new Set<string>();
   #callbacks = new CallbackRegistry();
@@ -315,27 +310,27 @@ export class Connection extends EventEmitter {
     const object = JSON.parse(message);
     if (object.method === 'Target.attachedToTarget') {
       const sessionId = object.params.sessionId;
-      const session = new CDPSessionImpl(
+      const session = new CDPCDPSession(
         this,
         object.params.targetInfo.type,
         sessionId,
         object.sessionId
       );
       this.#sessions.set(sessionId, session);
-      this.emit('sessionattached', session);
+      this.emit(CDPSessionEvent.SessionAttached, session);
       const parentSession = this.#sessions.get(object.sessionId);
       if (parentSession) {
-        parentSession.emit('sessionattached', session);
+        parentSession.emit(CDPSessionEvent.SessionAttached, session);
       }
     } else if (object.method === 'Target.detachedFromTarget') {
       const session = this.#sessions.get(object.params.sessionId);
       if (session) {
         session._onClosed();
         this.#sessions.delete(object.params.sessionId);
-        this.emit('sessiondetached', session);
+        this.emit(CDPSessionEvent.SessionDetached, session);
         const parentSession = this.#sessions.get(object.sessionId);
         if (parentSession) {
-          parentSession.emit('sessiondetached', session);
+          parentSession.emit(CDPSessionEvent.SessionDetached, session);
         }
       }
     }
@@ -371,7 +366,7 @@ export class Connection extends EventEmitter {
       session._onClosed();
     }
     this.#sessions.clear();
-    this.emit(ConnectionEmittedEvents.Disconnected);
+    this.emit(CDPSessionEvent.Disconnected, undefined);
   }
 
   dispose(): void {
@@ -422,240 +417,7 @@ export class Connection extends EventEmitter {
 /**
  * @internal
  */
-export interface CDPSessionOnMessageObject {
+export function createProtocolErrorMessage(object: {
-  id?: number;
-  method: string;
-  params: Record<string, unknown>;
-  error: {message: string; data: any; code: number};
-  result?: any;
-}
-
-/**
- * Internal events that the CDPSession class emits.
- *
- * @internal
- */
-export const CDPSessionEmittedEvents = {
-  Disconnected: Symbol('CDPSession.Disconnected'),
-  Swapped: Symbol('CDPSession.Swapped'),
-  /**
-   * Emitted when the session is ready to be configured during the auto-attach
-   * process. Right after the event is handled, the session will be resumed.
-   */
-  Ready: Symbol('CDPSession.Ready'),
-} as const;
-
-/**
- * The `CDPSession` instances are used to talk raw Chrome Devtools Protocol.
- *
- * @remarks
- *
- * Protocol methods can be called with {@link CDPSession.send} method and protocol
- * events can be subscribed to with `CDPSession.on` method.
- *
- * Useful links: {@link https://chromedevtools.github.io/devtools-protocol/ | DevTools Protocol Viewer}
- * and {@link https://github.com/aslushnikov/getting-started-with-cdp/blob/HEAD/README.md | Getting Started with DevTools Protocol}.
- *
- * @example
- *
- * ```ts
- * const client = await page.target().createCDPSession();
- * await client.send('Animation.enable');
- * client.on('Animation.animationCreated', () =>
- *   console.log('Animation created!')
- * );
- * const response = await client.send('Animation.getPlaybackRate');
- * console.log('playback rate is ' + response.playbackRate);
- * await client.send('Animation.setPlaybackRate', {
- *   playbackRate: response.playbackRate / 2,
- * });
- * ```
- *
- * @public
- */
-export class CDPSession extends EventEmitter {
-  /**
-   * @internal
-   */
-  constructor() {
-    super();
-  }
-
-  connection(): Connection | undefined {
-    throw new Error('Not implemented');
-  }
-
-  /**
-   * Parent session in terms of CDP's auto-attach mechanism.
-   *
-   * @internal
-   */
-  parentSession(): CDPSession | undefined {
-    return undefined;
-  }
-
-  send<T extends keyof ProtocolMapping.Commands>(
-    method: T,
-    ...paramArgs: ProtocolMapping.Commands[T]['paramsType']
-  ): Promise<ProtocolMapping.Commands[T]['returnType']>;
-  send<T extends keyof ProtocolMapping.Commands>(): Promise<
-    ProtocolMapping.Commands[T]['returnType']
-  > {
-    throw new Error('Not implemented');
-  }
-
-  /**
-   * Detaches the cdpSession from the target. Once detached, the cdpSession object
-   * won't emit any events and can't be used to send messages.
-   */
-  async detach(): Promise<void> {
-    throw new Error('Not implemented');
-  }
-
-  /**
-   * Returns the session's id.
-   */
-  id(): string {
-    throw new Error('Not implemented');
-  }
-}
-
-/**
- * @internal
- */
-export class CDPSessionImpl extends CDPSession {
-  #sessionId: string;
-  #targetType: string;
-  #callbacks = new CallbackRegistry();
-  #connection?: Connection;
-  #parentSessionId?: string;
-  #target?: CDPTarget;
-
-  /**
-   * @internal
-   */
-  constructor(
-    connection: Connection,
-    targetType: string,
-    sessionId: string,
-    parentSessionId: string | undefined
-  ) {
-    super();
-    this.#connection = connection;
-    this.#targetType = targetType;
-    this.#sessionId = sessionId;
-    this.#parentSessionId = parentSessionId;
-  }
-
-  /**
-   * Sets the CDPTarget associated with the session instance.
-   *
-   * @internal
-   */
-  _setTarget(target: CDPTarget): void {
-    this.#target = target;
-  }
-
-  /**
-   * Gets the CDPTarget associated with the session instance.
-   *
-   * @internal
-   */
-  _target(): CDPTarget {
-    assert(this.#target, 'Target must exist');
-    return this.#target;
-  }
-
-  override connection(): Connection | undefined {
-    return this.#connection;
-  }
-
-  override parentSession(): CDPSession | undefined {
-    if (!this.#parentSessionId) {
-      return;
-    }
-    const parent = this.#connection?.session(this.#parentSessionId);
-    return parent ?? undefined;
-  }
-
-  override send<T extends keyof ProtocolMapping.Commands>(
-    method: T,
-    ...paramArgs: ProtocolMapping.Commands[T]['paramsType']
-  ): Promise<ProtocolMapping.Commands[T]['returnType']> {
-    if (!this.#connection) {
-      return Promise.reject(
-        new TargetCloseError(
-          `Protocol error (${method}): Session closed. Most likely the ${
-            this.#targetType
-          } has been closed.`
-        )
-      );
-    }
-    // See the comment in Connection#send explaining why we do this.
-    const params = paramArgs.length ? paramArgs[0] : undefined;
-    return this.#connection._rawSend(
-      this.#callbacks,
-      method,
-      params,
-      this.#sessionId
-    );
-  }
-
-  /**
-   * @internal
-   */
-  _onMessage(object: CDPSessionOnMessageObject): void {
-    if (object.id) {
-      if (object.error) {
-        this.#callbacks.reject(
-          object.id,
-          createProtocolErrorMessage(object),
-          object.error.message
-        );
-      } else {
-        this.#callbacks.resolve(object.id, object.result);
-      }
-    } else {
-      assert(!object.id);
-      this.emit(object.method, object.params);
-    }
-  }
-
-  /**
-   * Detaches the cdpSession from the target. Once detached, the cdpSession object
-   * won't emit any events and can't be used to send messages.
-   */
-  override async detach(): Promise<void> {
-    if (!this.#connection) {
-      throw new Error(
-        `Session already detached. Most likely the ${
-          this.#targetType
-        } has been closed.`
-      );
-    }
-    await this.#connection.send('Target.detachFromTarget', {
-      sessionId: this.#sessionId,
-    });
-  }
-
-  /**
-   * @internal
-   */
-  _onClosed(): void {
-    this.#callbacks.clear();
-    this.#connection = undefined;
-    this.emit(CDPSessionEmittedEvents.Disconnected);
-  }
-
-  /**
-   * Returns the session's id.
-   */
-  override id(): string {
-    return this.#sessionId;
-  }
-}
-
-function createProtocolErrorMessage(object: {
   error: {message: string; data: any; code: number};
 }): string {
   let message = `${object.error.message}`;

packages/puppeteer-core/src/common/Coverage.ts

@@ -16,21 +16,11 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {assert} from '../util/assert.js';
 
-import {CDPSession} from './Connection.js';
+import {EventSubscription} from './EventEmitter.js';
-import {
+import {debugError, PuppeteerURL} from './util.js';
-  addEventListener,
-  debugError,
-  PuppeteerEventListener,
-  PuppeteerURL,
-  removeEventListeners,
-} from './util.js';
-
-/**
- * @internal
- */
-export {PuppeteerEventListener};
 
 /**
  * The CoverageEntry class represents one entry of the coverage report.
@@ -211,7 +201,7 @@ export class JSCoverage {
   #enabled = false;
   #scriptURLs = new Map<string, string>();
   #scriptSources = new Map<string, string>();
-  #eventListeners: PuppeteerEventListener[] = [];
+  #subscriptions?: DisposableStack;
   #resetOnNavigation = false;
   #reportAnonymousScripts = false;
   #includeRawScriptCoverage = false;
@@ -248,18 +238,21 @@ export class JSCoverage {
     this.#enabled = true;
     this.#scriptURLs.clear();
     this.#scriptSources.clear();
-    this.#eventListeners = [
+    this.#subscriptions = new DisposableStack();
-      addEventListener(
+    this.#subscriptions.use(
+      new EventSubscription(
         this.#client,
         'Debugger.scriptParsed',
         this.#onScriptParsed.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         this.#client,
         'Runtime.executionContextsCleared',
         this.#onExecutionContextsCleared.bind(this)
-      ),
+      )
-    ];
+    );
     await Promise.all([
       this.#client.send('Profiler.enable'),
       this.#client.send('Profiler.startPreciseCoverage', {
@@ -313,7 +306,7 @@ export class JSCoverage {
       this.#client.send('Debugger.disable'),
     ]);
 
-    removeEventListeners(this.#eventListeners);
+    this.#subscriptions?.dispose();
 
     const coverage = [];
     const profileResponse = result[0];
@@ -350,7 +343,7 @@ export class CSSCoverage {
   #enabled = false;
   #stylesheetURLs = new Map<string, string>();
   #stylesheetSources = new Map<string, string>();
-  #eventListeners: PuppeteerEventListener[] = [];
+  #eventListeners?: DisposableStack;
   #resetOnNavigation = false;
 
   constructor(client: CDPSession) {
@@ -371,18 +364,21 @@ export class CSSCoverage {
     this.#enabled = true;
     this.#stylesheetURLs.clear();
     this.#stylesheetSources.clear();
-    this.#eventListeners = [
+    this.#eventListeners = new DisposableStack();
-      addEventListener(
+    this.#eventListeners.use(
+      new EventSubscription(
         this.#client,
         'CSS.styleSheetAdded',
         this.#onStyleSheet.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#eventListeners.use(
+      new EventSubscription(
         this.#client,
         'Runtime.executionContextsCleared',
         this.#onExecutionContextsCleared.bind(this)
-      ),
+      )
-    ];
+    );
     await Promise.all([
       this.#client.send('DOM.enable'),
       this.#client.send('CSS.enable'),
@@ -426,7 +422,7 @@ export class CSSCoverage {
       this.#client.send('CSS.disable'),
       this.#client.send('DOM.disable'),
     ]);
-    removeEventListeners(this.#eventListeners);
+    this.#eventListeners?.dispose();
 
     // aggregate by styleSheetId
     const styleSheetIdToCoverage = new Map();

packages/puppeteer-core/src/common/DeviceRequestPrompt.test.ts

@@ -18,6 +18,8 @@ import {describe, it} from 'node:test';
 
 import expect from 'expect';
 
+import {CDPSessionEvents} from '../api/CDPSession.js';
+
 import {
   DeviceRequestPrompt,
   DeviceRequestPromptDevice,
@@ -27,7 +29,7 @@ import {TimeoutError} from './Errors.js';
 import {EventEmitter} from './EventEmitter.js';
 import {TimeoutSettings} from './TimeoutSettings.js';
 
-class MockCDPSession extends EventEmitter {
+class MockCDPSession extends EventEmitter<CDPSessionEvents> {
   async send(): Promise<any> {}
   connection() {
     return undefined;

packages/puppeteer-core/src/common/DeviceRequestPrompt.ts

@@ -16,11 +16,11 @@
 
 import Protocol from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {WaitTimeoutOptions} from '../api/Page.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 
-import {CDPSession} from './Connection.js';
 import {TimeoutSettings} from './TimeoutSettings.js';
 
 /**

packages/puppeteer-core/src/common/Dialog.ts

@@ -16,10 +16,9 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {Dialog} from '../api/Dialog.js';
 
-import {CDPSession} from './Connection.js';
-
 /**
  * @internal
  */

packages/puppeteer-core/src/common/ElementHandle.ts

@@ -16,12 +16,12 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {AutofillData, ElementHandle, Point} from '../api/ElementHandle.js';
 import {Page, ScreenshotOptions} from '../api/Page.js';
 import {assert} from '../util/assert.js';
 import {throwIfDisposed} from '../util/decorators.js';
 
-import {CDPSession} from './Connection.js';
 import {CDPFrame} from './Frame.js';
 import {FrameManager} from './FrameManager.js';
 import {IsolatedWorld} from './IsolatedWorld.js';

packages/puppeteer-core/src/common/EmulationManager.ts

@@ -15,12 +15,12 @@
  */
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
 import {GeolocationOptions, MediaFeature} from '../api/Page.js';
 import {assert} from '../util/assert.js';
 import {invokeAtMostOnceForArguments} from '../util/decorators.js';
 import {isErrorLike} from '../util/ErrorLike.js';
 
-import {CDPSession, CDPSessionEmittedEvents} from './Connection.js';
 import {Viewport} from './PuppeteerViewport.js';
 import {debugError} from './util.js';
 
@@ -168,8 +168,8 @@ export class EmulationManager {
 
   async registerSpeculativeSession(client: CDPSession): Promise<void> {
     this.#secondaryClients.add(client);
-    client.once(CDPSessionEmittedEvents.Disconnected, () => {
+    client.once(CDPSessionEvent.Disconnected, () => {
-      return this.#secondaryClients.delete(client);
+      this.#secondaryClients.delete(client);
     });
     // We don't await here because we want to register all state changes before
     // the target is unpaused.

packages/puppeteer-core/src/common/EventEmitter.test.ts

@@ -22,7 +22,7 @@ import sinon from 'sinon';
 import {EventEmitter} from './EventEmitter.js';
 
 describe('EventEmitter', () => {
-  let emitter: EventEmitter;
+  let emitter: EventEmitter<Record<string, unknown>>;
 
   beforeEach(() => {
     emitter = new EventEmitter();
@@ -33,7 +33,7 @@ describe('EventEmitter', () => {
       it(`${methodName}: adds an event listener that is fired when the event is emitted`, () => {
         const listener = sinon.spy();
         emitter[methodName]('foo', listener);
-        emitter.emit('foo');
+        emitter.emit('foo', undefined);
         expect(listener.callCount).toEqual(1);
       });
 
@@ -62,10 +62,10 @@ describe('EventEmitter', () => {
       it(`${methodName}: removes the listener so it is no longer called`, () => {
         const listener = sinon.spy();
         emitter.on('foo', listener);
-        emitter.emit('foo');
+        emitter.emit('foo', undefined);
         expect(listener.callCount).toEqual(1);
         emitter.off('foo', listener);
-        emitter.emit('foo');
+        emitter.emit('foo', undefined);
         expect(listener.callCount).toEqual(1);
       });
 
@@ -85,9 +85,9 @@ describe('EventEmitter', () => {
     it('only calls the listener once and then removes it', () => {
       const listener = sinon.spy();
       emitter.once('foo', listener);
-      emitter.emit('foo');
+      emitter.emit('foo', undefined);
       expect(listener.callCount).toEqual(1);
-      emitter.emit('foo');
+      emitter.emit('foo', undefined);
       expect(listener.callCount).toEqual(1);
     });
 
@@ -105,7 +105,7 @@ describe('EventEmitter', () => {
       const listener3 = sinon.spy();
       emitter.on('foo', listener1).on('foo', listener2).on('bar', listener3);
 
-      emitter.emit('foo');
+      emitter.emit('foo', undefined);
 
       expect(listener1.callCount).toEqual(1);
       expect(listener2.callCount).toEqual(1);
@@ -125,13 +125,13 @@ describe('EventEmitter', () => {
     it('returns true if the event has listeners', () => {
       const listener = sinon.spy();
       emitter.on('foo', listener);
-      expect(emitter.emit('foo')).toBe(true);
+      expect(emitter.emit('foo', undefined)).toBe(true);
     });
 
     it('returns false if the event has listeners', () => {
       const listener = sinon.spy();
       emitter.on('foo', listener);
-      expect(emitter.emit('notFoo')).toBe(false);
+      expect(emitter.emit('notFoo', undefined)).toBe(false);
     });
   });
 
@@ -151,8 +151,8 @@ describe('EventEmitter', () => {
       emitter.on('foo', () => {}).on('bar', () => {});
 
       emitter.removeAllListeners();
-      expect(emitter.emit('foo')).toBe(false);
+      expect(emitter.emit('foo', undefined)).toBe(false);
-      expect(emitter.emit('bar')).toBe(false);
+      expect(emitter.emit('bar', undefined)).toBe(false);
     });
 
     it('returns the emitter for chaining', () => {
@@ -166,8 +166,8 @@ describe('EventEmitter', () => {
         .on('bar', () => {});
 
       emitter.removeAllListeners('bar');
-      expect(emitter.emit('foo')).toBe(true);
+      expect(emitter.emit('foo', undefined)).toBe(true);
-      expect(emitter.emit('bar')).toBe(false);
+      expect(emitter.emit('bar', undefined)).toBe(false);
     });
   });
 });

packages/puppeteer-core/src/common/EventEmitter.ts

@@ -14,12 +14,20 @@
  * limitations under the License.
  */
 
-import mitt, {Emitter, EventHandlerMap} from '../../third_party/mitt/index.js';
+import {Symbol} from '../../third_party/disposablestack/disposablestack.js';
+import mitt, {
+  Emitter,
+  EventHandlerMap,
+  EventType,
+} from '../../third_party/mitt/index.js';
 
+export {
   /**
    * @public
    */
-export type EventType = string | symbol;
+  EventType,
+} from '../../third_party/mitt/index.js';
+
 /**
  * @public
  */
@@ -28,22 +36,42 @@ export type Handler<T = unknown> = (event: T) => void;
 /**
  * @public
  */
-export interface CommonEventEmitter {
+export interface CommonEventEmitter<Events extends Record<EventType, unknown>> {
-  on(event: EventType, handler: Handler): this;
+  on<Key extends keyof Events>(type: Key, handler: Handler<Events[Key]>): this;
-  off(event: EventType, handler: Handler): this;
+  off<Key extends keyof Events>(
+    type: Key,
+    handler?: Handler<Events[Key]>
+  ): this;
+  emit<Key extends keyof Events>(type: Key, event: Events[Key]): boolean;
   /* To maintain parity with the built in NodeJS event emitter which uses removeListener
    * rather than `off`.
    * If you're implementing new code you should use `off`.
    */
-  addListener(event: EventType, handler: Handler): this;
+  addListener<Key extends keyof Events>(
-  removeListener(event: EventType, handler: Handler): this;
+    type: Key,
-  emit(event: EventType, eventData?: unknown): boolean;
+    handler: Handler<Events[Key]>
-  once(event: EventType, handler: Handler): this;
+  ): this;
-  listenerCount(event: string): number;
+  removeListener<Key extends keyof Events>(
+    type: Key,
+    handler: Handler<Events[Key]>
+  ): this;
+  once<Key extends keyof Events>(
+    type: Key,
+    handler: Handler<Events[Key]>
+  ): this;
+  listenerCount(event: keyof Events): number;
 
-  removeAllListeners(event?: EventType): this;
+  removeAllListeners(event?: keyof Events): this;
 }
 
+/**
+ * @public
+ */
+export type EventsWithWildcard<Events extends Record<EventType, unknown>> =
+  Events & {
+    '*': Events[keyof Events];
+  };
+
 /**
  * The EventEmitter class that many Puppeteer classes extend.
  *
@@ -56,110 +84,153 @@ export interface CommonEventEmitter {
  *
  * @public
  */
-export class EventEmitter implements CommonEventEmitter {
+export class EventEmitter<Events extends Record<EventType, unknown>>
-  private emitter: Emitter<Record<string | symbol, any>>;
+  implements CommonEventEmitter<EventsWithWildcard<Events>>
-  private eventsMap: EventHandlerMap<Record<string | symbol, any>> = new Map();
+{
+  #emitter: Emitter<Events & {'*': Events[keyof Events]}>;
+  #handlers: EventHandlerMap<Events & {'*': Events[keyof Events]}> = new Map();
 
   /**
    * @internal
    */
   constructor() {
-    this.emitter = mitt(this.eventsMap);
+    this.#emitter = mitt(this.#handlers);
   }
 
   /**
    * Bind an event listener to fire when an event occurs.
-   * @param event - the event type you'd like to listen to. Can be a string or symbol.
+   * @param type - the event type you'd like to listen to. Can be a string or symbol.
    * @param handler - the function to be called when the event occurs.
    * @returns `this` to enable you to chain method calls.
    */
-  on(event: EventType, handler: Handler<any>): this {
+  on<Key extends keyof EventsWithWildcard<Events>>(
-    this.emitter.on(event, handler);
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this {
+    this.#emitter.on(type, handler);
     return this;
   }
 
   /**
    * Remove an event listener from firing.
-   * @param event - the event type you'd like to stop listening to.
+   * @param type - the event type you'd like to stop listening to.
    * @param handler - the function that should be removed.
    * @returns `this` to enable you to chain method calls.
    */
-  off(event: EventType, handler: Handler<any>): this {
+  off<Key extends keyof EventsWithWildcard<Events>>(
-    this.emitter.off(event, handler);
+    type: Key,
+    handler?: Handler<EventsWithWildcard<Events>[Key]>
+  ): this {
+    this.#emitter.off(type, handler);
     return this;
   }
 
   /**
    * Remove an event listener.
+   *
    * @deprecated please use {@link EventEmitter.off} instead.
    */
-  removeListener(event: EventType, handler: Handler<any>): this {
+  removeListener<Key extends keyof EventsWithWildcard<Events>>(
-    this.off(event, handler);
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this {
+    this.off(type, handler);
     return this;
   }
 
   /**
    * Add an event listener.
+   *
    * @deprecated please use {@link EventEmitter.on} instead.
    */
-  addListener(event: EventType, handler: Handler<any>): this {
+  addListener<Key extends keyof EventsWithWildcard<Events>>(
-    this.on(event, handler);
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this {
+    this.on(type, handler);
     return this;
   }
 
   /**
    * Emit an event and call any associated listeners.
    *
-   * @param event - the event you'd like to emit
+   * @param type - the event you'd like to emit
    * @param eventData - any data you'd like to emit with the event
    * @returns `true` if there are any listeners, `false` if there are not.
    */
-  emit(event: EventType, eventData?: unknown): boolean {
+  emit<Key extends keyof EventsWithWildcard<Events>>(
-    this.emitter.emit(event, eventData);
+    type: Key,
-    return this.eventListenersCount(event) > 0;
+    event: EventsWithWildcard<Events>[Key]
+  ): boolean {
+    this.#emitter.emit(type, event);
+    return this.listenerCount(type) > 0;
   }
 
   /**
    * Like `on` but the listener will only be fired once and then it will be removed.
-   * @param event - the event you'd like to listen to
+   * @param type - the event you'd like to listen to
    * @param handler - the handler function to run when the event occurs
    * @returns `this` to enable you to chain method calls.
    */
-  once(event: EventType, handler: Handler<any>): this {
+  once<Key extends keyof EventsWithWildcard<Events>>(
-    const onceHandler: Handler<any> = eventData => {
+    type: Key,
+    handler: Handler<EventsWithWildcard<Events>[Key]>
+  ): this {
+    const onceHandler: Handler<EventsWithWildcard<Events>[Key]> = eventData => {
       handler(eventData);
-      this.off(event, onceHandler);
+      this.off(type, onceHandler);
     };
 
-    return this.on(event, onceHandler);
+    return this.on(type, onceHandler);
   }
 
   /**
    * Gets the number of listeners for a given event.
    *
-   * @param event - the event to get the listener count for
+   * @param type - the event to get the listener count for
    * @returns the number of listeners bound to the given event
    */
-  listenerCount(event: EventType): number {
+  listenerCount(type: keyof EventsWithWildcard<Events>): number {
-    return this.eventListenersCount(event);
+    return this.#handlers.get(type)?.length || 0;
   }
 
   /**
    * Removes all listeners. If given an event argument, it will remove only
    * listeners for that event.
-   * @param event - the event to remove listeners for.
+   *
+   * @param type - the event to remove listeners for.
    * @returns `this` to enable you to chain method calls.
    */
-  removeAllListeners(event?: EventType): this {
+  removeAllListeners(type?: keyof EventsWithWildcard<Events>): this {
-    if (event) {
+    if (type === undefined || type === '*') {
-      this.eventsMap.delete(event);
+      this.#handlers.clear();
     } else {
-      this.eventsMap.clear();
+      this.#handlers.delete(type);
     }
     return this;
   }
+}
 
-  private eventListenersCount(event: EventType): number {
+/**
-    return this.eventsMap.get(event)?.length || 0;
+ * @internal
+ */
+export class EventSubscription<
+  Target extends CommonEventEmitter<Record<Type, Event>>,
+  Type extends EventType = EventType,
+  Event = unknown,
+> {
+  #target: Target;
+  #type: Type;
+  #handler: Handler<Event>;
+
+  constructor(target: Target, type: Type, handler: Handler<Event>) {
+    this.#target = target;
+    this.#type = type;
+    this.#handler = handler;
+    this.#target.on(this.#type, this.#handler);
+  }
+
+  [Symbol.dispose](): void {
+    this.#target.off(this.#type, this.#handler);
   }
 }

packages/puppeteer-core/src/common/ExecutionContext.ts

@@ -16,6 +16,7 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import type {ElementHandle} from '../api/ElementHandle.js';
 import {JSHandle} from '../api/JSHandle.js';
 import type PuppeteerUtil from '../injected/injected.js';
@@ -24,7 +25,6 @@ import {stringifyFunction} from '../util/Function.js';
 
 import {ARIAQueryHandler} from './AriaQueryHandler.js';
 import {Binding} from './Binding.js';
-import {CDPSession} from './Connection.js';
 import {CDPElementHandle} from './ElementHandle.js';
 import {IsolatedWorld} from './IsolatedWorld.js';
 import {CDPJSHandle} from './JSHandle.js';
@@ -47,25 +47,6 @@ const getSourceUrlComment = (url: string) => {
 };
 
 /**
- * Represents a context for JavaScript execution.
- *
- * @example
- * A {@link Page} can have several execution contexts:
- *
- * - Each {@link Frame} of a {@link Page | page} has a "default" execution
- *   context that is always created after frame is attached to DOM. This context
- *   is returned by the {@link Frame.realm} method.
- * - Each {@link https://developer.chrome.com/extensions | Chrome extensions}
- *   creates additional execution contexts to isolate their code.
- *
- * @remarks
- * By definition, each context is isolated from one another, however they are
- * all able to manipulate non-JavaScript resources (such as DOM).
- *
- * @remarks
- * Besides pages, execution contexts can be found in
- * {@link WebWorker | workers}.
- *
  * @internal
  */
 export class ExecutionContext {

packages/puppeteer-core/src/common/FirefoxTargetManager.ts

@@ -17,16 +17,18 @@
 import {Protocol} from 'devtools-protocol';
 
 import {TargetFilterCallback} from '../api/Browser.js';
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 
-import {CDPSession, CDPSessionEmittedEvents, Connection} from './Connection.js';
+import {Connection} from './Connection.js';
 import {EventEmitter} from './EventEmitter.js';
 import {CDPTarget} from './Target.js';
 import {
   TargetFactory,
-  TargetManagerEmittedEvents,
+  TargetManagerEvent,
   TargetManager,
+  TargetManagerEvents,
 } from './TargetManager.js';
 
 /**
@@ -44,7 +46,7 @@ import {
  *   @internal
  */
 export class FirefoxTargetManager
-  extends EventEmitter
+  extends EventEmitter<TargetManagerEvents>
   implements TargetManager
 {
   #connection: Connection;
@@ -98,7 +100,10 @@ export class FirefoxTargetManager
 
     this.#connection.on('Target.targetCreated', this.#onTargetCreated);
     this.#connection.on('Target.targetDestroyed', this.#onTargetDestroyed);
-    this.#connection.on('sessiondetached', this.#onSessionDetached);
+    this.#connection.on(
+      CDPSessionEvent.SessionDetached,
+      this.#onSessionDetached
+    );
     this.setupAttachmentListeners(this.#connection);
   }
 
@@ -172,7 +177,7 @@ export class FirefoxTargetManager
     }
     target._initialize();
     this.#availableTargetsByTargetId.set(event.targetInfo.targetId, target);
-    this.emit(TargetManagerEmittedEvents.TargetAvailable, target);
+    this.emit(TargetManagerEvent.TargetAvailable, target);
     this.#finishInitializationIfReady(target._targetId);
   };
 
@@ -181,7 +186,7 @@ export class FirefoxTargetManager
     this.#finishInitializationIfReady(event.targetId);
     const target = this.#availableTargetsByTargetId.get(event.targetId);
     if (target) {
-      this.emit(TargetManagerEmittedEvents.TargetGone, target);
+      this.emit(TargetManagerEvent.TargetGone, target);
       this.#availableTargetsByTargetId.delete(event.targetId);
     }
   };
@@ -207,7 +212,7 @@ export class FirefoxTargetManager
       this.#availableTargetsByTargetId.get(targetInfo.targetId)!
     );
 
-    parentSession.emit(CDPSessionEmittedEvents.Ready, session);
+    parentSession.emit(CDPSessionEvent.Ready, session);
   };
 
   #finishInitializationIfReady(targetId: string): void {

packages/puppeteer-core/src/common/Frame.ts

@@ -16,14 +16,14 @@
 
 import {Protocol} from 'devtools-protocol';
 
-import {Frame, throwIfDetached} from '../api/Frame.js';
+import {CDPSession} from '../api/CDPSession.js';
+import {Frame, FrameEvent, throwIfDetached} from '../api/Frame.js';
 import {HTTPResponse} from '../api/HTTPResponse.js';
 import {Page, WaitTimeoutOptions} from '../api/Page.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 import {isErrorLike} from '../util/ErrorLike.js';
 
-import {CDPSession} from './Connection.js';
 import {
   DeviceRequestPrompt,
   DeviceRequestPromptManager,
@@ -34,21 +34,6 @@ import {MAIN_WORLD, PUPPETEER_WORLD} from './IsolatedWorlds.js';
 import {LifecycleWatcher, PuppeteerLifeCycleEvent} from './LifecycleWatcher.js';
 import {setPageContent} from './util.js';
 
-/**
- * We use symbols to prevent external parties listening to these events.
- * They are internal to Puppeteer.
- *
- * @internal
- */
-export const FrameEmittedEvents = {
-  FrameNavigated: Symbol('Frame.FrameNavigated'),
-  FrameSwapped: Symbol('Frame.FrameSwapped'),
-  LifecycleEvent: Symbol('Frame.LifecycleEvent'),
-  FrameNavigatedWithinDocument: Symbol('Frame.FrameNavigatedWithinDocument'),
-  FrameDetached: Symbol('Frame.FrameDetached'),
-  FrameSwappedByActivation: Symbol('Frame.FrameSwappedByActivation'),
-};
-
 /**
  * @internal
  */
@@ -80,7 +65,7 @@ export class CDPFrame extends Frame {
 
     this.updateClient(client);
 
-    this.on(FrameEmittedEvents.FrameSwappedByActivation, () => {
+    this.on(FrameEvent.FrameSwappedByActivation, () => {
       // Emulate loading process for swapped frames.
       this._onLoadingStarted();
       this._onLoadingStopped();

packages/puppeteer-core/src/common/FrameManager.ts

@@ -16,21 +16,19 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
+import {FrameEvent} from '../api/Frame.js';
 import {Page} from '../api/Page.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 import {isErrorLike} from '../util/ErrorLike.js';
 
-import {
+import {CDPCDPSession} from './CDPSession.js';
-  CDPSession,
+import {isTargetClosedError} from './Connection.js';
-  CDPSessionEmittedEvents,
-  CDPSessionImpl,
-  isTargetClosedError,
-} from './Connection.js';
 import {DeviceRequestPromptManager} from './DeviceRequestPrompt.js';
-import {EventEmitter} from './EventEmitter.js';
+import {EventEmitter, EventType} from './EventEmitter.js';
 import {ExecutionContext} from './ExecutionContext.js';
-import {CDPFrame, FrameEmittedEvents} from './Frame.js';
+import {CDPFrame} from './Frame.js';
 import {FrameTree} from './FrameTree.js';
 import {IsolatedWorld} from './IsolatedWorld.js';
 import {MAIN_WORLD, PUPPETEER_WORLD} from './IsolatedWorlds.js';
@@ -50,16 +48,30 @@ export const UTILITY_WORLD_NAME = '__puppeteer_utility_world__';
  *
  * @internal
  */
-export const FrameManagerEmittedEvents = {
+// eslint-disable-next-line @typescript-eslint/no-namespace
-  FrameAttached: Symbol('FrameManager.FrameAttached'),
+export namespace FrameManagerEvent {
-  FrameNavigated: Symbol('FrameManager.FrameNavigated'),
+  export const FrameAttached = Symbol('FrameManager.FrameAttached');
-  FrameDetached: Symbol('FrameManager.FrameDetached'),
+  export const FrameNavigated = Symbol('FrameManager.FrameNavigated');
-  FrameSwapped: Symbol('FrameManager.FrameSwapped'),
+  export const FrameDetached = Symbol('FrameManager.FrameDetached');
-  LifecycleEvent: Symbol('FrameManager.LifecycleEvent'),
+  export const FrameSwapped = Symbol('FrameManager.FrameSwapped');
-  FrameNavigatedWithinDocument: Symbol(
+  export const LifecycleEvent = Symbol('FrameManager.LifecycleEvent');
+  export const FrameNavigatedWithinDocument = Symbol(
     'FrameManager.FrameNavigatedWithinDocument'
-  ),
+  );
-};
+}
+
+/**
+ * @internal
+ */
+
+export interface FrameManagerEvents extends Record<EventType, unknown> {
+  [FrameManagerEvent.FrameAttached]: CDPFrame;
+  [FrameManagerEvent.FrameNavigated]: CDPFrame;
+  [FrameManagerEvent.FrameDetached]: CDPFrame;
+  [FrameManagerEvent.FrameSwapped]: CDPFrame;
+  [FrameManagerEvent.LifecycleEvent]: CDPFrame;
+  [FrameManagerEvent.FrameNavigatedWithinDocument]: CDPFrame;
+}
 
 const TIME_FOR_WAITING_FOR_SWAP = 100; // ms.
 
@@ -68,7 +80,7 @@ const TIME_FOR_WAITING_FOR_SWAP = 100; // ms.
  *
  * @internal
  */
-export class FrameManager extends EventEmitter {
+export class FrameManager extends EventEmitter<FrameManagerEvents> {
   #page: Page;
   #networkManager: NetworkManager;
   #timeoutSettings: TimeoutSettings;
@@ -114,7 +126,7 @@ export class FrameManager extends EventEmitter {
     this.#networkManager = new NetworkManager(ignoreHTTPSErrors, this);
     this.#timeoutSettings = timeoutSettings;
     this.setupEventListeners(this.#client);
-    client.once(CDPSessionEmittedEvents.Disconnected, () => {
+    client.once(CDPSessionEvent.Disconnected, () => {
       this.#onClientDisconnect().catch(debugError);
     });
   }
@@ -136,7 +148,7 @@ export class FrameManager extends EventEmitter {
       timeout: TIME_FOR_WAITING_FOR_SWAP,
       message: 'Frame was not swapped',
     });
-    mainFrame.once(FrameEmittedEvents.FrameSwappedByActivation, () => {
+    mainFrame.once(FrameEvent.FrameSwappedByActivation, () => {
       swapped.resolve();
     });
     try {
@@ -156,7 +168,7 @@ export class FrameManager extends EventEmitter {
 
     this.#client = client;
     assert(
-      this.#client instanceof CDPSessionImpl,
+      this.#client instanceof CDPCDPSession,
       'CDPSession is not an instance of CDPSessionImpl.'
     );
     const frame = this._frameTree.getMainFrame();
@@ -170,17 +182,17 @@ export class FrameManager extends EventEmitter {
       frame.updateClient(client, true);
     }
     this.setupEventListeners(client);
-    client.once(CDPSessionEmittedEvents.Disconnected, () => {
+    client.once(CDPSessionEvent.Disconnected, () => {
       this.#onClientDisconnect().catch(debugError);
     });
     await this.initialize(client);
     await this.#networkManager.addClient(client);
     if (frame) {
-      frame.emit(FrameEmittedEvents.FrameSwappedByActivation);
+      frame.emit(FrameEvent.FrameSwappedByActivation, undefined);
     }
   }
 
-  async registerSpeculativeSession(client: CDPSessionImpl): Promise<void> {
+  async registerSpeculativeSession(client: CDPCDPSession): Promise<void> {
     await this.#networkManager.addClient(client);
   }
 
@@ -312,8 +324,8 @@ export class FrameManager extends EventEmitter {
       return;
     }
     frame._onLifecycleEvent(event.loaderId, event.name);
-    this.emit(FrameManagerEmittedEvents.LifecycleEvent, frame);
+    this.emit(FrameManagerEvent.LifecycleEvent, frame);
-    frame.emit(FrameEmittedEvents.LifecycleEvent);
+    frame.emit(FrameEvent.LifecycleEvent, undefined);
   }
 
   #onFrameStartedLoading(frameId: string): void {
@@ -330,8 +342,8 @@ export class FrameManager extends EventEmitter {
       return;
     }
     frame._onLoadingStopped();
-    this.emit(FrameManagerEmittedEvents.LifecycleEvent, frame);
+    this.emit(FrameManagerEvent.LifecycleEvent, frame);
-    frame.emit(FrameEmittedEvents.LifecycleEvent);
+    frame.emit(FrameEvent.LifecycleEvent, undefined);
   }
 
   #handleFrameTree(
@@ -378,7 +390,7 @@ export class FrameManager extends EventEmitter {
 
     frame = new CDPFrame(this, frameId, parentFrameId, session);
     this._frameTree.addFrame(frame);
-    this.emit(FrameManagerEmittedEvents.FrameAttached, frame);
+    this.emit(FrameManagerEvent.FrameAttached, frame);
   }
 
   async #onFrameNavigated(
@@ -412,8 +424,8 @@ export class FrameManager extends EventEmitter {
 
     frame = await this._frameTree.waitForFrame(frameId);
     frame._navigated(framePayload);
-    this.emit(FrameManagerEmittedEvents.FrameNavigated, frame);
+    this.emit(FrameManagerEvent.FrameNavigated, frame);
-    frame.emit(FrameEmittedEvents.FrameNavigated, navigationType);
+    frame.emit(FrameEvent.FrameNavigated, navigationType);
   }
 
   async #createIsolatedWorld(session: CDPSession, name: string): Promise<void> {
@@ -455,10 +467,10 @@ export class FrameManager extends EventEmitter {
       return;
     }
     frame._navigatedWithinDocument(url);
-    this.emit(FrameManagerEmittedEvents.FrameNavigatedWithinDocument, frame);
+    this.emit(FrameManagerEvent.FrameNavigatedWithinDocument, frame);
-    frame.emit(FrameEmittedEvents.FrameNavigatedWithinDocument);
+    frame.emit(FrameEvent.FrameNavigatedWithinDocument, undefined);
-    this.emit(FrameManagerEmittedEvents.FrameNavigated, frame);
+    this.emit(FrameManagerEvent.FrameNavigated, frame);
-    frame.emit(FrameEmittedEvents.FrameNavigated);
+    frame.emit(FrameEvent.FrameNavigated, 'Navigation');
   }
 
   #onFrameDetached(
@@ -466,16 +478,20 @@ export class FrameManager extends EventEmitter {
     reason: Protocol.Page.FrameDetachedEventReason
   ): void {
     const frame = this.frame(frameId);
-    if (reason === 'remove') {
+    if (!frame) {
+      return;
+    }
+    switch (reason) {
+      case 'remove':
         // Only remove the frame if the reason for the detached event is
         // an actual removement of the frame.
         // For frames that become OOP iframes, the reason would be 'swap'.
-      if (frame) {
         this.#removeFramesRecursively(frame);
-      }
+        break;
-    } else if (reason === 'swap') {
+      case 'swap':
-      this.emit(FrameManagerEmittedEvents.FrameSwapped, frame);
+        this.emit(FrameManagerEvent.FrameSwapped, frame);
-      frame?.emit(FrameEmittedEvents.FrameSwapped);
+        frame.emit(FrameEvent.FrameSwapped, undefined);
+        break;
     }
   }
 
@@ -555,7 +571,7 @@ export class FrameManager extends EventEmitter {
     }
     frame[Symbol.dispose]();
     this._frameTree.removeFrame(frame);
-    this.emit(FrameManagerEmittedEvents.FrameDetached, frame);
+    this.emit(FrameManagerEvent.FrameDetached, frame);
-    frame.emit(FrameEmittedEvents.FrameDetached, frame);
+    frame.emit(FrameEvent.FrameDetached, frame);
   }
 }

packages/puppeteer-core/src/common/HTTPRequest.ts

@@ -15,12 +15,13 @@
  */
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {Frame} from '../api/Frame.js';
 import {
   ContinueRequestOverrides,
   ErrorCode,
   headersArray,
-  HTTPRequest as BaseHTTPRequest,
+  HTTPRequest,
   InterceptResolutionAction,
   InterceptResolutionState,
   ResourceType,
@@ -30,20 +31,19 @@ import {
 import {HTTPResponse} from '../api/HTTPResponse.js';
 import {assert} from '../util/assert.js';
 
-import {CDPSession} from './Connection.js';
 import {ProtocolError} from './Errors.js';
 import {debugError, isString} from './util.js';
 
 /**
  * @internal
  */
-export class HTTPRequest extends BaseHTTPRequest {
+export class CDPHTTPRequest extends HTTPRequest {
   override _requestId: string;
   override _interceptionId: string | undefined;
   override _failureText: string | null = null;
   override _response: HTTPResponse | null = null;
   override _fromMemoryCache = false;
-  override _redirectChain: HTTPRequest[];
+  override _redirectChain: CDPHTTPRequest[];
 
   #client: CDPSession;
   #isNavigationRequest: boolean;
@@ -100,7 +100,7 @@ export class HTTPRequest extends BaseHTTPRequest {
        */
       type?: Protocol.Network.ResourceType;
     },
-    redirectChain: HTTPRequest[]
+    redirectChain: CDPHTTPRequest[]
   ) {
     super();
     this.#client = client;
@@ -213,7 +213,7 @@ export class HTTPRequest extends BaseHTTPRequest {
     return this.#initiator;
   }
 
-  override redirectChain(): HTTPRequest[] {
+  override redirectChain(): CDPHTTPRequest[] {
     return this._redirectChain.slice();
   }
 

packages/puppeteer-core/src/common/HTTPResponse.ts

@@ -15,24 +15,21 @@
  */
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {Frame} from '../api/Frame.js';
-import {
+import {HTTPResponse, RemoteAddress} from '../api/HTTPResponse.js';
-  HTTPResponse as BaseHTTPResponse,
-  RemoteAddress,
-} from '../api/HTTPResponse.js';
 import {Deferred} from '../util/Deferred.js';
 
-import {CDPSession} from './Connection.js';
 import {ProtocolError} from './Errors.js';
-import {HTTPRequest} from './HTTPRequest.js';
+import {CDPHTTPRequest} from './HTTPRequest.js';
 import {SecurityDetails} from './SecurityDetails.js';
 
 /**
  * @internal
  */
-export class HTTPResponse extends BaseHTTPResponse {
+export class CDPHTTPResponse extends HTTPResponse {
   #client: CDPSession;
-  #request: HTTPRequest;
+  #request: CDPHTTPRequest;
   #contentPromise: Promise<Buffer> | null = null;
   #bodyLoadedDeferred = Deferred.create<Error | void>();
   #remoteAddress: RemoteAddress;
@@ -47,7 +44,7 @@ export class HTTPResponse extends BaseHTTPResponse {
 
   constructor(
     client: CDPSession,
-    request: HTTPRequest,
+    request: CDPHTTPRequest,
     responsePayload: Protocol.Network.Response,
     extraInfo: Protocol.Network.ResponseReceivedExtraInfoEvent | null
   ) {
@@ -171,7 +168,7 @@ export class HTTPResponse extends BaseHTTPResponse {
     return this.#contentPromise;
   }
 
-  override request(): HTTPRequest {
+  override request(): CDPHTTPRequest {
     return this.#request;
   }
 

packages/puppeteer-core/src/common/Input.ts

@@ -16,6 +16,7 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {Point} from '../api/ElementHandle.js';
 import {
   Keyboard,
@@ -32,7 +33,6 @@ import {
 } from '../api/Input.js';
 import {assert} from '../util/assert.js';
 
-import {CDPSession} from './Connection.js';
 import {_keyDefinitions, KeyDefinition, KeyInput} from './USKeyboardLayout.js';
 
 type KeyDescription = Required<

packages/puppeteer-core/src/common/IsolatedWorld.ts

@@ -16,12 +16,12 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {JSHandle} from '../api/JSHandle.js';
 import {Realm} from '../api/Realm.js';
 import {Deferred} from '../util/Deferred.js';
 
 import {Binding} from './Binding.js';
-import {CDPSession} from './Connection.js';
 import {ExecutionContext} from './ExecutionContext.js';
 import {CDPFrame} from './Frame.js';
 import {MAIN_WORLD, PUPPETEER_WORLD} from './IsolatedWorlds.js';

packages/puppeteer-core/src/common/JSHandle.ts

@@ -16,9 +16,9 @@
 
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {JSHandle} from '../api/JSHandle.js';
 
-import {CDPSession} from './Connection.js';
 import type {CDPElementHandle} from './ElementHandle.js';
 import {IsolatedWorld} from './IsolatedWorld.js';
 import {releaseObject, valueFromRemoteObject} from './util.js';

packages/puppeteer-core/src/common/LifecycleWatcher.ts

@@ -16,20 +16,17 @@
 
 import Protocol from 'devtools-protocol';
 
+import {Frame, FrameEvent} from '../api/Frame.js';
 import {HTTPResponse} from '../api/HTTPResponse.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 
 import {TimeoutError} from './Errors.js';
-import {CDPFrame, FrameEmittedEvents} from './Frame.js';
+import {EventSubscription} from './EventEmitter.js';
-import {FrameManagerEmittedEvents} from './FrameManager.js';
+import {CDPFrame} from './Frame.js';
-import {HTTPRequest} from './HTTPRequest.js';
+import {FrameManagerEvent} from './FrameManager.js';
-import {NetworkManager, NetworkManagerEmittedEvents} from './NetworkManager.js';
+import {CDPHTTPRequest} from './HTTPRequest.js';
-import {
+import {NetworkManager, NetworkManagerEvent} from './NetworkManager.js';
-  addEventListener,
-  PuppeteerEventListener,
-  removeEventListeners,
-} from './util.js';
 /**
  * @public
  */
@@ -65,8 +62,8 @@ export class LifecycleWatcher {
   #expectedLifecycle: ProtocolLifeCycleEvent[];
   #frame: CDPFrame;
   #timeout: number;
-  #navigationRequest: HTTPRequest | null = null;
+  #navigationRequest: CDPHTTPRequest | null = null;
-  #eventListeners: PuppeteerEventListener[];
+  #subscriptions = new DisposableStack();
   #initialLoaderId: string;
 
   #terminationDeferred: Deferred<Error>;
@@ -99,55 +96,70 @@ export class LifecycleWatcher {
 
     this.#frame = frame;
     this.#timeout = timeout;
-    this.#eventListeners = [
+    this.#subscriptions.use(
-      addEventListener(
       // Revert if TODO #1 is done
+      new EventSubscription(
         frame._frameManager,
-        FrameManagerEmittedEvents.LifecycleEvent,
+        FrameManagerEvent.LifecycleEvent,
         this.#checkLifecycleComplete.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         frame,
-        FrameEmittedEvents.FrameNavigatedWithinDocument,
+        FrameEvent.FrameNavigatedWithinDocument,
         this.#navigatedWithinDocument.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         frame,
-        FrameEmittedEvents.FrameNavigated,
+        FrameEvent.FrameNavigated,
         this.#navigated.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         frame,
-        FrameEmittedEvents.FrameSwapped,
+        FrameEvent.FrameSwapped,
         this.#frameSwapped.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         frame,
-        FrameEmittedEvents.FrameSwappedByActivation,
+        FrameEvent.FrameSwappedByActivation,
         this.#frameSwapped.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         frame,
-        FrameEmittedEvents.FrameDetached,
+        FrameEvent.FrameDetached,
         this.#onFrameDetached.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         networkManager,
-        NetworkManagerEmittedEvents.Request,
+        NetworkManagerEvent.Request,
         this.#onRequest.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         networkManager,
-        NetworkManagerEmittedEvents.Response,
+        NetworkManagerEvent.Response,
         this.#onResponse.bind(this)
-      ),
+      )
-      addEventListener(
+    );
+    this.#subscriptions.use(
+      new EventSubscription(
         networkManager,
-        NetworkManagerEmittedEvents.RequestFailed,
+        NetworkManagerEvent.RequestFailed,
         this.#onRequestFailed.bind(this)
-      ),
+      )
-    ];
+    );
-
     this.#terminationDeferred = Deferred.create<Error>({
       timeout: this.#timeout,
       message: `Navigation timeout of ${this.#timeout} ms exceeded`,
@@ -156,7 +168,7 @@ export class LifecycleWatcher {
     this.#checkLifecycleComplete();
   }
 
-  #onRequest(request: HTTPRequest): void {
+  #onRequest(request: CDPHTTPRequest): void {
     if (request.frame() !== this.#frame || !request.isNavigationRequest()) {
       return;
     }
@@ -171,7 +183,7 @@ export class LifecycleWatcher {
     }
   }
 
-  #onRequestFailed(request: HTTPRequest): void {
+  #onRequestFailed(request: CDPHTTPRequest): void {
     if (this.#navigationRequest?._requestId !== request._requestId) {
       return;
     }
@@ -185,7 +197,7 @@ export class LifecycleWatcher {
     this.#navigationResponseReceived?.resolve();
   }
 
-  #onFrameDetached(frame: CDPFrame): void {
+  #onFrameDetached(frame: Frame): void {
     if (this.#frame === frame) {
       this.#terminationDeferred.resolve(
         new Error('Navigating frame was detached')
@@ -273,7 +285,7 @@ export class LifecycleWatcher {
   }
 
   dispose(): void {
-    removeEventListeners(this.#eventListeners);
+    this.#subscriptions.dispose();
     this.#terminationDeferred.resolve(new Error('LifecycleWatcher disposed'));
   }
 }

packages/puppeteer-core/src/common/NetworkEventManager.ts

@@ -16,7 +16,7 @@
 
 import {Protocol} from 'devtools-protocol';
 
-import {HTTPRequest} from './HTTPRequest.js';
+import {CDPHTTPRequest} from './HTTPRequest.js';
 
 /**
  * @internal
@@ -92,7 +92,7 @@ export class NetworkEventManager {
     NetworkRequestId,
     Protocol.Fetch.RequestPausedEvent
   >();
-  #httpRequestsMap = new Map<NetworkRequestId, HTTPRequest>();
+  #httpRequestsMap = new Map<NetworkRequestId, CDPHTTPRequest>();
 
   /*
    * The below maps are used to reconcile Network.responseReceivedExtraInfo
@@ -193,11 +193,14 @@ export class NetworkEventManager {
     this.#requestPausedMap.set(networkRequestId, event);
   }
 
-  getRequest(networkRequestId: NetworkRequestId): HTTPRequest | undefined {
+  getRequest(networkRequestId: NetworkRequestId): CDPHTTPRequest | undefined {
     return this.#httpRequestsMap.get(networkRequestId);
   }
 
-  storeRequest(networkRequestId: NetworkRequestId, request: HTTPRequest): void {
+  storeRequest(
+    networkRequestId: NetworkRequestId,
+    request: CDPHTTPRequest
+  ): void {
     this.#httpRequestsMap.set(networkRequestId, request);
   }
 

packages/puppeteer-core/src/common/NetworkManager.test.ts

@@ -18,17 +18,18 @@ import {describe, it} from 'node:test';
 
 import expect from 'expect';
 
+import {CDPSessionEvents} from '../api/CDPSession.js';
 import {HTTPRequest} from '../api/HTTPRequest.js';
 import {HTTPResponse} from '../api/HTTPResponse.js';
 
 import {EventEmitter} from './EventEmitter.js';
 import {CDPFrame} from './Frame.js';
-import {NetworkManager, NetworkManagerEmittedEvents} from './NetworkManager.js';
+import {NetworkManager, NetworkManagerEvent} from './NetworkManager.js';
 
 // TODO: develop a helper to generate fake network events for attributes that
 // are not relevant for the network manager to make tests shorter.
 
-class MockCDPSession extends EventEmitter {
+class MockCDPSession extends EventEmitter<CDPSessionEvents> {
   async send(): Promise<any> {}
   connection() {
     return undefined;
@@ -153,6 +154,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 162,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 2111.557593,
           proxyStart: -1,
           proxyEnd: -1,
@@ -241,6 +243,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 162,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 2111.559346,
           proxyStart: -1,
           proxyEnd: -1,
@@ -344,6 +347,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 178,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 2111.560482,
           proxyStart: -1,
           proxyEnd: -1,
@@ -448,6 +452,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 197,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 2111.561759,
           proxyStart: -1,
           proxyEnd: -1,
@@ -486,13 +491,10 @@ describe('NetworkManager', () => {
     await manager.setRequestInterception(true);
 
     const requests: HTTPRequest[] = [];
-    manager.on(
+    manager.on(NetworkManagerEvent.Request, async (request: HTTPRequest) => {
-      NetworkManagerEmittedEvents.Request,
-      async (request: HTTPRequest) => {
       requests.push(request);
       await request.continue();
-      }
+    });
-    );
 
     /**
      * This sequence was taken from an actual CDP session produced by the following
@@ -519,7 +521,7 @@ describe('NetworkManager', () => {
       request: {
         url: 'https://www.google.com/',
         method: 'GET',
-        headers: [Object],
+        headers: {},
         mixedContentType: 'none',
         initialPriority: 'VeryHigh',
         referrerPolicy: 'strict-origin-when-cross-origin',
@@ -538,7 +540,7 @@ describe('NetworkManager', () => {
       request: {
         url: 'https://www.google.com/',
         method: 'GET',
-        headers: [Object],
+        headers: {},
         initialPriority: 'VeryHigh',
         referrerPolicy: 'strict-origin-when-cross-origin',
       },
@@ -551,7 +553,7 @@ describe('NetworkManager', () => {
       request: {
         url: 'https://www.google.com/',
         method: 'GET',
-        headers: [Object],
+        headers: {},
         initialPriority: 'VeryHigh',
         referrerPolicy: 'strict-origin-when-cross-origin',
       },
@@ -572,12 +574,9 @@ describe('NetworkManager', () => {
     await manager.addClient(mockCDPSession);
 
     const requests: HTTPRequest[] = [];
-    manager.on(
+    manager.on(NetworkManagerEvent.RequestFinished, (request: HTTPRequest) => {
-      NetworkManagerEmittedEvents.RequestFinished,
-      (request: HTTPRequest) => {
       requests.push(request);
-      }
+    });
-    );
 
     mockCDPSession.emit('Network.requestWillBeSent', {
       requestId: '1360.2',
@@ -633,6 +632,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 66,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 10959.023904,
           proxyStart: -1,
           proxyEnd: -1,
@@ -692,14 +692,11 @@ describe('NetworkManager', () => {
 
     const finishedRequests: HTTPRequest[] = [];
     const pendingRequests: HTTPRequest[] = [];
-    manager.on(
+    manager.on(NetworkManagerEvent.RequestFinished, (request: HTTPRequest) => {
-      NetworkManagerEmittedEvents.RequestFinished,
-      (request: HTTPRequest) => {
       finishedRequests.push(request);
-      }
+    });
-    );
 
-    manager.on(NetworkManagerEmittedEvents.Request, (request: HTTPRequest) => {
+    manager.on(NetworkManagerEvent.Request, (request: HTTPRequest) => {
       pendingRequests.push(request);
     });
 
@@ -756,6 +753,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 197,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 671.232585,
           proxyStart: -1,
           proxyEnd: -1,
@@ -845,14 +843,11 @@ describe('NetworkManager', () => {
 
     const responses: HTTPResponse[] = [];
     const requests: HTTPRequest[] = [];
-    manager.on(
+    manager.on(NetworkManagerEvent.Response, (response: HTTPResponse) => {
-      NetworkManagerEmittedEvents.Response,
-      (response: HTTPResponse) => {
       responses.push(response);
-      }
+    });
-    );
 
-    manager.on(NetworkManagerEmittedEvents.Request, (request: HTTPRequest) => {
+    manager.on(NetworkManagerEvent.Request, (request: HTTPRequest) => {
       requests.push(request);
     });
 
@@ -966,6 +961,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 197,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 504904.000422,
           proxyStart: -1,
           proxyEnd: -1,
@@ -1009,14 +1005,11 @@ describe('NetworkManager', () => {
 
     const responses: HTTPResponse[] = [];
     const requests: HTTPRequest[] = [];
-    manager.on(
+    manager.on(NetworkManagerEvent.Response, (response: HTTPResponse) => {
-      NetworkManagerEmittedEvents.Response,
-      (response: HTTPResponse) => {
       responses.push(response);
-      }
+    });
-    );
 
-    manager.on(NetworkManagerEmittedEvents.Request, (request: HTTPRequest) => {
+    manager.on(NetworkManagerEvent.Request, (request: HTTPRequest) => {
       requests.push(request);
     });
 
@@ -1072,6 +1065,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 197,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 510294.106734,
           proxyStart: -1,
           proxyEnd: -1,
@@ -1156,14 +1150,11 @@ describe('NetworkManager', () => {
 
     const responses: HTTPResponse[] = [];
     const requests: HTTPRequest[] = [];
-    manager.on(
+    manager.on(NetworkManagerEvent.Response, (response: HTTPResponse) => {
-      NetworkManagerEmittedEvents.Response,
-      (response: HTTPResponse) => {
       responses.push(response);
-      }
+    });
-    );
 
-    manager.on(NetworkManagerEmittedEvents.Request, (request: HTTPRequest) => {
+    manager.on(NetworkManagerEvent.Request, (request: HTTPRequest) => {
       requests.push(request);
     });
 
@@ -1260,6 +1251,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 197,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 31949.959838,
           proxyStart: -1,
           proxyEnd: -1,
@@ -1432,6 +1424,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 182,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 31949.983605,
           proxyStart: -1,
           proxyEnd: -1,
@@ -1492,6 +1485,7 @@ describe('NetworkManager', () => {
         fromPrefetchCache: false,
         encodedDataLength: 0,
         timing: {
+          receiveHeadersStart: 0,
           requestTime: 31949.988855,
           proxyStart: -1,
           proxyEnd: -1,

packages/puppeteer-core/src/common/NetworkManager.ts

@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-import {Protocol} from 'devtools-protocol';
+import type {Protocol} from 'devtools-protocol';
 
-import {Frame} from '../api/Frame.js';
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
+import type {Frame} from '../api/Frame.js';
 import {assert} from '../util/assert.js';
 
-import {CDPSession, CDPSessionEmittedEvents} from './Connection.js';
+import {EventEmitter, EventSubscription, EventType} from './EventEmitter.js';
-import {EventEmitter, Handler} from './EventEmitter.js';
+import {CDPHTTPRequest} from './HTTPRequest.js';
-import {HTTPRequest} from './HTTPRequest.js';
+import {CDPHTTPResponse} from './HTTPResponse.js';
-import {HTTPResponse} from './HTTPResponse.js';
 import {FetchRequestId, NetworkEventManager} from './NetworkEventManager.js';
 import {debugError, isString} from './util.js';
 
@@ -58,13 +58,27 @@ export interface InternalNetworkConditions extends NetworkConditions {
  *
  * @internal
  */
-export const NetworkManagerEmittedEvents = {
+// eslint-disable-next-line @typescript-eslint/no-namespace
-  Request: Symbol('NetworkManager.Request'),
+export namespace NetworkManagerEvent {
-  RequestServedFromCache: Symbol('NetworkManager.RequestServedFromCache'),
+  export const Request = Symbol('NetworkManager.Request');
-  Response: Symbol('NetworkManager.Response'),
+  export const RequestServedFromCache = Symbol(
-  RequestFailed: Symbol('NetworkManager.RequestFailed'),
+    'NetworkManager.RequestServedFromCache'
-  RequestFinished: Symbol('NetworkManager.RequestFinished'),
+  );
-} as const;
+  export const Response = Symbol('NetworkManager.Response');
+  export const RequestFailed = Symbol('NetworkManager.RequestFailed');
+  export const RequestFinished = Symbol('NetworkManager.RequestFinished');
+}
+
+/**
+ * @internal
+ */
+export interface NetworkManagerEvents extends Record<EventType, unknown> {
+  [NetworkManagerEvent.Request]: CDPHTTPRequest;
+  [NetworkManagerEvent.RequestServedFromCache]: CDPHTTPRequest | undefined;
+  [NetworkManagerEvent.Response]: CDPHTTPResponse;
+  [NetworkManagerEvent.RequestFailed]: CDPHTTPRequest;
+  [NetworkManagerEvent.RequestFinished]: CDPHTTPRequest;
+}
 
 /**
  * @internal
@@ -76,7 +90,7 @@ export interface FrameProvider {
 /**
  * @internal
  */
-export class NetworkManager extends EventEmitter {
+export class NetworkManager extends EventEmitter<NetworkManagerEvents> {
   #ignoreHTTPSErrors: boolean;
   #frameManager: FrameProvider;
   #networkEventManager = new NetworkEventManager();
@@ -90,7 +104,7 @@ export class NetworkManager extends EventEmitter {
   #userAgent?: string;
   #userAgentMetadata?: Protocol.Emulation.UserAgentMetadata;
 
-  #handlers = new Map<string, Function>([
+  #handlers = Object.freeze([
     ['Fetch.requestPaused', this.#onRequestPaused],
     ['Fetch.authRequired', this.#onAuthRequired],
     ['Network.requestWillBeSent', this.#onRequestWillBeSent],
@@ -99,12 +113,10 @@ export class NetworkManager extends EventEmitter {
     ['Network.loadingFinished', this.#onLoadingFinished],
     ['Network.loadingFailed', this.#onLoadingFailed],
     ['Network.responseReceivedExtraInfo', this.#onResponseReceivedExtraInfo],
-  ]);
+    [CDPSessionEvent.Disconnected, this.#removeClient],
+  ] as const);
 
-  #clients = new Map<
+  #clients = new Map<CDPSession, DisposableStack>();
-    CDPSession,
-    Array<{event: string | symbol; handler: Handler}>
-  >();
 
   constructor(ignoreHTTPSErrors: boolean, frameManager: FrameProvider) {
     super();
@@ -116,20 +128,16 @@ export class NetworkManager extends EventEmitter {
     if (this.#clients.has(client)) {
       return;
     }
-    const listeners: Array<{event: string | symbol; handler: Handler}> = [];
+    const subscriptions = new DisposableStack();
-    this.#clients.set(client, listeners);
+    this.#clients.set(client, subscriptions);
     for (const [event, handler] of this.#handlers) {
-      listeners.push({
+      subscriptions.use(
-        event,
+        // TODO: Remove any here.
-        handler: handler.bind(this, client),
+        new EventSubscription(client, event, (arg: any) => {
-      });
+          return handler.bind(this)(client, arg);
-      client.on(event, listeners.at(-1)!.handler);
+        })
+      );
     }
-    listeners.push({
-      event: CDPSessionEmittedEvents.Disconnected,
-      handler: this.#removeClient.bind(this, client),
-    });
-    client.on(CDPSessionEmittedEvents.Disconnected, listeners.at(-1)!.handler);
     await Promise.all([
       this.#ignoreHTTPSErrors
         ? client.send('Security.setIgnoreCertificateErrors', {
@@ -146,10 +154,7 @@ export class NetworkManager extends EventEmitter {
   }
 
   async #removeClient(client: CDPSession) {
-    const listeners = this.#clients.get(client);
+    this.#clients.get(client)?.dispose();
-    for (const {event, handler} of listeners || []) {
-      client.off(event, handler);
-    }
     this.#clients.delete(client);
   }
 
@@ -447,7 +452,7 @@ export class NetworkManager extends EventEmitter {
       ? this.#frameManager.frame(event.frameId)
       : null;
 
-    const request = new HTTPRequest(
+    const request = new CDPHTTPRequest(
       client,
       frame,
       event.requestId,
@@ -455,7 +460,7 @@ export class NetworkManager extends EventEmitter {
       event,
       []
     );
-    this.emit(NetworkManagerEmittedEvents.Request, request);
+    this.emit(NetworkManagerEvent.Request, request);
     void request.finalizeInterceptions();
   }
 
@@ -464,7 +469,7 @@ export class NetworkManager extends EventEmitter {
     event: Protocol.Network.RequestWillBeSentEvent,
     fetchRequestId?: FetchRequestId
   ): void {
-    let redirectChain: HTTPRequest[] = [];
+    let redirectChain: CDPHTTPRequest[] = [];
     if (event.redirectResponse) {
       // We want to emit a response and requestfinished for the
       // redirectResponse, but we can't do so unless we have a
@@ -504,7 +509,7 @@ export class NetworkManager extends EventEmitter {
       ? this.#frameManager.frame(event.frameId)
       : null;
 
-    const request = new HTTPRequest(
+    const request = new CDPHTTPRequest(
       client,
       frame,
       fetchRequestId,
@@ -513,7 +518,7 @@ export class NetworkManager extends EventEmitter {
       redirectChain
     );
     this.#networkEventManager.storeRequest(event.requestId, request);
-    this.emit(NetworkManagerEmittedEvents.Request, request);
+    this.emit(NetworkManagerEvent.Request, request);
     void request.finalizeInterceptions();
   }
 
@@ -525,16 +530,16 @@ export class NetworkManager extends EventEmitter {
     if (request) {
       request._fromMemoryCache = true;
     }
-    this.emit(NetworkManagerEmittedEvents.RequestServedFromCache, request);
+    this.emit(NetworkManagerEvent.RequestServedFromCache, request);
   }
 
   #handleRequestRedirect(
     client: CDPSession,
-    request: HTTPRequest,
+    request: CDPHTTPRequest,
     responsePayload: Protocol.Network.Response,
     extraInfo: Protocol.Network.ResponseReceivedExtraInfoEvent | null
   ): void {
-    const response = new HTTPResponse(
+    const response = new CDPHTTPResponse(
       client,
       request,
       responsePayload,
@@ -546,8 +551,8 @@ export class NetworkManager extends EventEmitter {
       new Error('Response body is unavailable for redirect responses')
     );
     this.#forgetRequest(request, false);
-    this.emit(NetworkManagerEmittedEvents.Response, response);
+    this.emit(NetworkManagerEvent.Response, response);
-    this.emit(NetworkManagerEmittedEvents.RequestFinished, request);
+    this.emit(NetworkManagerEvent.RequestFinished, request);
   }
 
   #emitResponseEvent(
@@ -582,14 +587,14 @@ export class NetworkManager extends EventEmitter {
       extraInfo = null;
     }
 
-    const response = new HTTPResponse(
+    const response = new CDPHTTPResponse(
       client,
       request,
       responseReceived.response,
       extraInfo
     );
     request._response = response;
-    this.emit(NetworkManagerEmittedEvents.Response, response);
+    this.emit(NetworkManagerEvent.Response, response);
   }
 
   #onResponseReceived(
@@ -654,7 +659,7 @@ export class NetworkManager extends EventEmitter {
     this.#networkEventManager.responseExtraInfo(event.requestId).push(event);
   }
 
-  #forgetRequest(request: HTTPRequest, events: boolean): void {
+  #forgetRequest(request: CDPHTTPRequest, events: boolean): void {
     const requestId = request._requestId;
     const interceptionId = request._interceptionId;
 
@@ -697,7 +702,7 @@ export class NetworkManager extends EventEmitter {
       request.response()?._resolveBody(null);
     }
     this.#forgetRequest(request, true);
-    this.emit(NetworkManagerEmittedEvents.RequestFinished, request);
+    this.emit(NetworkManagerEvent.RequestFinished, request);
   }
 
   #onLoadingFailed(
@@ -729,6 +734,6 @@ export class NetworkManager extends EventEmitter {
       response._resolveBody(null);
     }
     this.#forgetRequest(request, true);
-    this.emit(NetworkManagerEmittedEvents.RequestFailed, request);
+    this.emit(NetworkManagerEvent.RequestFailed, request);
   }
 }

packages/puppeteer-core/src/common/Page.ts

@@ -20,6 +20,7 @@ import {Protocol} from 'devtools-protocol';
 
 import type {Browser} from '../api/Browser.js';
 import type {BrowserContext} from '../api/BrowserContext.js';
+import {CDPSession, CDPSessionEvent} from '../api/CDPSession.js';
 import {ElementHandle} from '../api/ElementHandle.js';
 import {Frame} from '../api/Frame.js';
 import {HTTPRequest} from '../api/HTTPRequest.js';
@@ -31,7 +32,7 @@ import {
   Metrics,
   NewDocumentScriptEvaluation,
   Page,
-  PageEmittedEvents,
+  PageEvent,
   ScreenshotClip,
   ScreenshotOptions,
   WaitForOptions,
@@ -43,33 +44,28 @@ import {isErrorLike} from '../util/ErrorLike.js';
 
 import {Accessibility} from './Accessibility.js';
 import {Binding} from './Binding.js';
-import {
+import {CDPCDPSession} from './CDPSession.js';
-  CDPSession,
+import {isTargetClosedError} from './Connection.js';
-  CDPSessionEmittedEvents,
-  CDPSessionImpl,
-  isTargetClosedError,
-} from './Connection.js';
 import {ConsoleMessage, ConsoleMessageType} from './ConsoleMessage.js';
 import {Coverage} from './Coverage.js';
 import {DeviceRequestPrompt} from './DeviceRequestPrompt.js';
 import {CDPDialog} from './Dialog.js';
 import {EmulationManager} from './EmulationManager.js';
 import {TargetCloseError} from './Errors.js';
-import {Handler} from './EventEmitter.js';
 import {FileChooser} from './FileChooser.js';
 import {CDPFrame} from './Frame.js';
-import {FrameManager, FrameManagerEmittedEvents} from './FrameManager.js';
+import {FrameManager, FrameManagerEvent} from './FrameManager.js';
 import {CDPKeyboard, CDPMouse, CDPTouchscreen} from './Input.js';
 import {MAIN_WORLD} from './IsolatedWorlds.js';
 import {
   Credentials,
   NetworkConditions,
-  NetworkManagerEmittedEvents,
+  NetworkManagerEvent,
 } from './NetworkManager.js';
 import {PDFOptions} from './PDFOptions.js';
 import {Viewport} from './PuppeteerViewport.js';
 import {CDPTarget} from './Target.js';
-import {TargetManagerEmittedEvents} from './TargetManager.js';
+import {TargetManagerEvent} from './TargetManager.js';
 import {TaskQueue} from './TaskQueue.js';
 import {TimeoutSettings} from './TimeoutSettings.js';
 import {Tracing} from './Tracing.js';
@@ -146,58 +142,81 @@ export class CDPPage extends Page {
   #serviceWorkerBypassed = false;
   #userDragInterceptionEnabled = false;
 
-  #frameManagerHandlers = new Map<symbol, Handler<any>>([
+  #frameManagerHandlers = Object.freeze([
     [
-      FrameManagerEmittedEvents.FrameAttached,
+      FrameManagerEvent.FrameAttached,
-      this.emit.bind(this, PageEmittedEvents.FrameAttached),
+      (frame: CDPFrame) => {
+        this.emit(PageEvent.FrameAttached, frame);
+      },
     ],
     [
-      FrameManagerEmittedEvents.FrameDetached,
+      FrameManagerEvent.FrameDetached,
-      this.emit.bind(this, PageEmittedEvents.FrameDetached),
+      (frame: CDPFrame) => {
+        this.emit(PageEvent.FrameDetached, frame);
+      },
     ],
     [
-      FrameManagerEmittedEvents.FrameNavigated,
+      FrameManagerEvent.FrameNavigated,
-      this.emit.bind(this, PageEmittedEvents.FrameNavigated),
+      (frame: CDPFrame) => {
+        this.emit(PageEvent.FrameNavigated, frame);
+      },
     ],
-  ]);
+  ] as const);
 
-  #networkManagerHandlers = new Map<symbol, Handler<any>>([
+  #networkManagerHandlers = Object.freeze([
     [
-      NetworkManagerEmittedEvents.Request,
+      NetworkManagerEvent.Request,
-      this.emit.bind(this, PageEmittedEvents.Request),
+      (request: HTTPRequest) => {
+        this.emit(PageEvent.Request, request);
+      },
     ],
     [
-      NetworkManagerEmittedEvents.RequestServedFromCache,
+      NetworkManagerEvent.RequestServedFromCache,
-      this.emit.bind(this, PageEmittedEvents.RequestServedFromCache),
+      (request: HTTPRequest) => {
+        this.emit(PageEvent.RequestServedFromCache, request);
+      },
     ],
     [
-      NetworkManagerEmittedEvents.Response,
+      NetworkManagerEvent.Response,
-      this.emit.bind(this, PageEmittedEvents.Response),
+      (response: HTTPResponse) => {
+        this.emit(PageEvent.Response, response);
+      },
     ],
     [
-      NetworkManagerEmittedEvents.RequestFailed,
+      NetworkManagerEvent.RequestFailed,
-      this.emit.bind(this, PageEmittedEvents.RequestFailed),
+      (request: HTTPRequest) => {
+        this.emit(PageEvent.RequestFailed, request);
+      },
     ],
     [
-      NetworkManagerEmittedEvents.RequestFinished,
+      NetworkManagerEvent.RequestFinished,
-      this.emit.bind(this, PageEmittedEvents.RequestFinished),
+      (request: HTTPRequest) => {
+        this.emit(PageEvent.RequestFinished, request);
+      },
     ],
-  ]);
+  ] as const);
 
-  #sessionHandlers = new Map<symbol | string, Handler<any>>([
+  #sessionHandlers = Object.freeze([
     [
-      CDPSessionEmittedEvents.Disconnected,
+      CDPSessionEvent.Disconnected,
       () => {
-        return this.#sessionCloseDeferred.resolve(
+        this.#sessionCloseDeferred.resolve(
           new TargetCloseError('Target closed')
         );
       },
     ],
     [
       'Page.domContentEventFired',
-      this.emit.bind(this, PageEmittedEvents.DOMContentLoaded),
+      () => {
+        return this.emit(PageEvent.DOMContentLoaded, undefined);
+      },
+    ],
+    [
+      'Page.loadEventFired',
+      () => {
+        return this.emit(PageEvent.Load, undefined);
+      },
     ],
-    ['Page.loadEventFired', this.emit.bind(this, PageEmittedEvents.Load)],
     ['Runtime.consoleAPICalled', this.#onConsoleAPI.bind(this)],
     ['Runtime.bindingCalled', this.#onBindingCalled.bind(this)],
     ['Page.javascriptDialogOpening', this.#onDialog.bind(this)],
@@ -206,7 +225,7 @@ export class CDPPage extends Page {
     ['Performance.metrics', this.#emitMetrics.bind(this)],
     ['Log.entryAdded', this.#onLogEntryAdded.bind(this)],
     ['Page.fileChooserOpened', this.#onFileChooser.bind(this)],
-  ]);
+  ] as const);
 
   constructor(
     client: CDPSession,
@@ -236,10 +255,10 @@ export class CDPPage extends Page {
 
     this.#setupEventListeners();
 
-    this.#tabSession?.on(CDPSessionEmittedEvents.Swapped, async newSession => {
+    this.#tabSession?.on(CDPSessionEvent.Swapped, async newSession => {
       this.#client = newSession;
       assert(
-        this.#client instanceof CDPSessionImpl,
+        this.#client instanceof CDPCDPSession,
         'CDPSession is not instance of CDPSessionImpl'
       );
       this.#target = this.#client._target();
@@ -254,57 +273,49 @@ export class CDPPage extends Page {
       await this.#frameManager.swapFrameTree(newSession);
       this.#setupEventListeners();
     });
-    this.#tabSession?.on(
+    this.#tabSession?.on(CDPSessionEvent.Ready, session => {
-      CDPSessionEmittedEvents.Ready,
+      assert(session instanceof CDPCDPSession);
-      (session: CDPSessionImpl) => {
       if (session._target()._subtype() !== 'prerender') {
         return;
       }
-        this.#frameManager
+      this.#frameManager.registerSpeculativeSession(session).catch(debugError);
-          .registerSpeculativeSession(session)
-          .catch(debugError);
       this.#emulationManager
         .registerSpeculativeSession(session)
         .catch(debugError);
-      }
+    });
-    );
   }
 
   #setupEventListeners() {
-    this.#client.on(CDPSessionEmittedEvents.Ready, this.#onAttachedToTarget);
+    this.#client.on(CDPSessionEvent.Ready, this.#onAttachedToTarget);
 
     this.#target
       ._targetManager()
-      .on(TargetManagerEmittedEvents.TargetGone, this.#onDetachedFromTarget);
+      .on(TargetManagerEvent.TargetGone, this.#onDetachedFromTarget);
 
     for (const [eventName, handler] of this.#frameManagerHandlers) {
       this.#frameManager.on(eventName, handler);
     }
 
     for (const [eventName, handler] of this.#networkManagerHandlers) {
-      this.#frameManager.networkManager.on(eventName, handler);
+      // TODO: Remove any.
+      this.#frameManager.networkManager.on(eventName, handler as any);
     }
 
     for (const [eventName, handler] of this.#sessionHandlers) {
-      this.#client.on(eventName, handler);
+      // TODO: Remove any.
+      this.#client.on(eventName, handler as any);
     }
 
     this.#target._isClosedDeferred
       .valueOrThrow()
       .then(() => {
-        this.#client.off(
+        this.#client.off(CDPSessionEvent.Ready, this.#onAttachedToTarget);
-          CDPSessionEmittedEvents.Ready,
-          this.#onAttachedToTarget
-        );
 
         this.#target
           ._targetManager()
-          .off(
+          .off(TargetManagerEvent.TargetGone, this.#onDetachedFromTarget);
-            TargetManagerEmittedEvents.TargetGone,
-            this.#onDetachedFromTarget
-          );
 
-        this.emit(PageEmittedEvents.Close);
+        this.emit(PageEvent.Close, undefined);
         this.#closed = true;
       })
       .catch(debugError);
@@ -317,10 +328,11 @@ export class CDPPage extends Page {
       return;
     }
     this.#workers.delete(sessionId!);
-    this.emit(PageEmittedEvents.WorkerDestroyed, worker);
+    this.emit(PageEvent.WorkerDestroyed, worker);
   };
 
-  #onAttachedToTarget = (session: CDPSessionImpl) => {
+  #onAttachedToTarget = (session: CDPSession) => {
+    assert(session instanceof CDPCDPSession);
     this.#frameManager.onAttachedToTarget(session._target());
     if (session._target()._getTargetInfo().type === 'worker') {
       const worker = new WebWorker(
@@ -330,9 +342,9 @@ export class CDPPage extends Page {
         this.#handleException.bind(this)
       );
       this.#workers.set(session.id(), worker);
-      this.emit(PageEmittedEvents.WorkerCreated, worker);
+      this.emit(PageEvent.WorkerCreated, worker);
     }
-    session.on(CDPSessionEmittedEvents.Ready, this.#onAttachedToTarget);
+    session.on(CDPSessionEvent.Ready, this.#onAttachedToTarget);
   };
 
   async #initialize(): Promise<void> {
@@ -434,7 +446,7 @@ export class CDPPage extends Page {
   }
 
   #onTargetCrashed(): void {
-    this.emit('error', new Error('Page crashed!'));
+    this.emit(PageEvent.Error, new Error('Page crashed!'));
   }
 
   #onLogEntryAdded(event: Protocol.Log.EntryAddedEvent): void {
@@ -446,7 +458,7 @@ export class CDPPage extends Page {
     }
     if (source !== 'worker') {
       this.emit(
-        PageEmittedEvents.Console,
+        PageEvent.Console,
         new ConsoleMessage(level, text, [], [{url, lineNumber}])
       );
     }
@@ -703,7 +715,7 @@ export class CDPPage extends Page {
   }
 
   #emitMetrics(event: Protocol.Performance.MetricsEvent): void {
-    this.emit(PageEmittedEvents.Metrics, {
+    this.emit(PageEvent.Metrics, {
       title: event.title,
       metrics: this.#buildMetricsObject(event.metrics),
     });
@@ -724,7 +736,7 @@ export class CDPPage extends Page {
 
   #handleException(exception: Protocol.Runtime.ExceptionThrownEvent): void {
     this.emit(
-      PageEmittedEvents.PageError,
+      PageEvent.PageError,
       createClientError(exception.exceptionDetails)
     );
   }
@@ -801,7 +813,7 @@ export class CDPPage extends Page {
     args: JSHandle[],
     stackTrace?: Protocol.Runtime.StackTrace
   ): void {
-    if (!this.listenerCount(PageEmittedEvents.Console)) {
+    if (!this.listenerCount(PageEvent.Console)) {
       args.forEach(arg => {
         return arg.dispose();
       });
@@ -834,7 +846,7 @@ export class CDPPage extends Page {
       args,
       stackTraceLocations
     );
-    this.emit(PageEmittedEvents.Console, message);
+    this.emit(PageEvent.Console, message);
   }
 
   #onDialog(event: Protocol.Page.JavascriptDialogOpeningEvent): void {
@@ -845,7 +857,7 @@ export class CDPPage extends Page {
       event.message,
       event.defaultPrompt
     );
-    this.emit(PageEmittedEvents.Dialog, dialog);
+    this.emit(PageEvent.Dialog, dialog);
   }
 
   override async reload(
@@ -870,7 +882,7 @@ export class CDPPage extends Page {
     const {timeout = this.#timeoutSettings.timeout()} = options;
     return await waitForEvent(
       this.#frameManager.networkManager,
-      NetworkManagerEmittedEvents.Request,
+      NetworkManagerEvent.Request,
       async request => {
         if (isString(urlOrPredicate)) {
           return urlOrPredicate === request.url();
@@ -894,7 +906,7 @@ export class CDPPage extends Page {
     const {timeout = this.#timeoutSettings.timeout()} = options;
     return await waitForEvent(
       this.#frameManager.networkManager,
-      NetworkManagerEmittedEvents.Response,
+      NetworkManagerEvent.Response,
       async response => {
         if (isString(urlOrPredicate)) {
           return urlOrPredicate === response.url();

packages/puppeteer-core/src/common/Target.ts

@@ -18,11 +18,12 @@ import {Protocol} from 'devtools-protocol';
 
 import type {Browser} from '../api/Browser.js';
 import type {BrowserContext} from '../api/BrowserContext.js';
-import {Page, PageEmittedEvents} from '../api/Page.js';
+import {CDPSession} from '../api/CDPSession.js';
+import {Page, PageEvent} from '../api/Page.js';
 import {Target, TargetType} from '../api/Target.js';
 import {Deferred} from '../util/Deferred.js';
 
-import {CDPSession, CDPSessionImpl} from './Connection.js';
+import {CDPCDPSession} from './CDPSession.js';
 import {CDPPage} from './Page.js';
 import {Viewport} from './PuppeteerViewport.js';
 import {TargetManager} from './TargetManager.js';
@@ -75,7 +76,7 @@ export class CDPTarget extends Target {
     this.#browserContext = browserContext;
     this._targetId = targetInfo.targetId;
     this.#sessionFactory = sessionFactory;
-    if (this.#session && this.#session instanceof CDPSessionImpl) {
+    if (this.#session && this.#session instanceof CDPCDPSession) {
       this.#session._setTarget(this);
     }
   }
@@ -102,7 +103,7 @@ export class CDPTarget extends Target {
       throw new Error('sessionFactory is not initialized');
     }
     return this.#sessionFactory(false).then(session => {
-      (session as CDPSessionImpl)._setTarget(this);
+      (session as CDPCDPSession)._setTarget(this);
       return session;
     });
   }
@@ -222,11 +223,11 @@ export class PageTarget extends CDPTarget {
           return true;
         }
         const openerPage = await opener.pagePromise;
-        if (!openerPage.listenerCount(PageEmittedEvents.Popup)) {
+        if (!openerPage.listenerCount(PageEvent.Popup)) {
           return true;
         }
         const popupPage = await this.page();
-        openerPage.emit(PageEmittedEvents.Popup, popupPage);
+        openerPage.emit(PageEvent.Popup, popupPage);
         return true;
       })
       .catch(debugError);

packages/puppeteer-core/src/common/TargetManager.ts

@@ -16,8 +16,9 @@
 
 import {Protocol} from 'devtools-protocol';
 
-import {CDPSession} from './Connection.js';
+import {CDPSession} from '../api/CDPSession.js';
-import {EventEmitter} from './EventEmitter.js';
+
+import {EventEmitter, EventType} from './EventEmitter.js';
 import {CDPTarget} from './Target.js';
 
 /**
@@ -29,6 +30,33 @@ export type TargetFactory = (
   parentSession?: CDPSession
 ) => CDPTarget;
 
+/**
+ * @internal
+ */
+export const enum TargetManagerEvent {
+  TargetDiscovered = 'targetDiscovered',
+  TargetAvailable = 'targetAvailable',
+  TargetGone = 'targetGone',
+  /**
+   * Emitted after a target has been initialized and whenever its URL changes.
+   */
+  TargetChanged = 'targetChanged',
+}
+
+/**
+ * @internal
+ */
+export interface TargetManagerEvents extends Record<EventType, unknown> {
+  [TargetManagerEvent.TargetAvailable]: CDPTarget;
+  [TargetManagerEvent.TargetDiscovered]: Protocol.Target.TargetInfo;
+  [TargetManagerEvent.TargetGone]: CDPTarget;
+  [TargetManagerEvent.TargetChanged]: {
+    target: CDPTarget;
+    wasInitialized: true;
+    previousURL: string;
+  };
+}
+
 /**
  * TargetManager encapsulates all interactions with CDP targets and is
  * responsible for coordinating the configuration of targets with the rest of
@@ -40,21 +68,8 @@ export type TargetFactory = (
  *
  * @internal
  */
-export interface TargetManager extends EventEmitter {
+export interface TargetManager extends EventEmitter<TargetManagerEvents> {
   getAvailableTargets(): Map<string, CDPTarget>;
   initialize(): Promise<void>;
   dispose(): void;
 }
-
-/**
- * @internal
- */
-export const enum TargetManagerEmittedEvents {
-  TargetDiscovered = 'targetDiscovered',
-  TargetAvailable = 'targetAvailable',
-  TargetGone = 'targetGone',
-  /**
-   * Emitted after a target has been initialized and whenever its URL changes.
-   */
-  TargetChanged = 'targetChanged',
-}

packages/puppeteer-core/src/common/Tracing.ts

@@ -13,11 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+import {CDPSession} from '../api/CDPSession.js';
 import {assert} from '../util/assert.js';
 import {Deferred} from '../util/Deferred.js';
 import {isErrorLike} from '../util/ErrorLike.js';
 
-import {CDPSession} from './Connection.js';
 import {getReadableAsBuffer, getReadableFromProtocolStream} from './util.js';
 
 /**
@@ -126,6 +126,7 @@ export class Tracing {
     const contentDeferred = Deferred.create<Buffer | undefined>();
     this.#client.once('Tracing.tracingComplete', async event => {
       try {
+        assert(event.stream, 'Missing "stream"');
         const readable = await getReadableFromProtocolStream(
           this.#client,
           event.stream

packages/puppeteer-core/src/common/WebWorker.ts

@@ -15,11 +15,11 @@
  */
 import {Protocol} from 'devtools-protocol';
 
+import {CDPSession} from '../api/CDPSession.js';
 import {Realm} from '../api/Realm.js';
 
-import {CDPSession} from './Connection.js';
 import {ConsoleMessageType} from './ConsoleMessage.js';
-import {EventEmitter} from './EventEmitter.js';
+import {EventEmitter, EventType} from './EventEmitter.js';
 import {ExecutionContext} from './ExecutionContext.js';
 import {IsolatedWorld} from './IsolatedWorld.js';
 import {CDPJSHandle} from './JSHandle.js';
@@ -33,7 +33,7 @@ import {debugError, withSourcePuppeteerURLIfNone} from './util.js';
 export type ConsoleAPICalledCallback = (
   eventType: ConsoleMessageType,
   handles: CDPJSHandle[],
-  trace: Protocol.Runtime.StackTrace
+  trace?: Protocol.Runtime.StackTrace
 ) => void;
 
 /**
@@ -69,7 +69,7 @@ export type ExceptionThrownCallback = (
  *
  * @public
  */
-export class WebWorker extends EventEmitter {
+export class WebWorker extends EventEmitter<Record<EventType, unknown>> {
   /**
    * @internal
    */

packages/puppeteer-core/src/common/bidi/BidiOverCDP.ts

@@ -18,22 +18,19 @@ import * as BidiMapper from 'chromium-bidi/lib/cjs/bidiMapper/bidiMapper.js';
 import * as Bidi from 'chromium-bidi/lib/cjs/protocol/protocol.js';
 import type {ProtocolMapping} from 'devtools-protocol/types/protocol-mapping.js';
 
-import {CDPSession, Connection as CDPPPtrConnection} from '../Connection.js';
+import {CDPEvents, CDPSession} from '../../api/CDPSession.js';
+import {Connection as CDPConnection} from '../Connection.js';
 import {TargetCloseError} from '../Errors.js';
-import {EventEmitter, Handler} from '../EventEmitter.js';
+import {Handler} from '../EventEmitter.js';
 
-import {Connection as BidiPPtrConnection} from './Connection.js';
+import {BidiConnection} from './Connection.js';
-
-type CdpEvents = {
-  [Property in keyof ProtocolMapping.Events]: ProtocolMapping.Events[Property][0];
-};
 
 /**
  * @internal
  */
 export async function connectBidiOverCDP(
-  cdp: CDPPPtrConnection
+  cdp: CDPConnection
-): Promise<BidiPPtrConnection> {
+): Promise<BidiConnection> {
   const transportBiDi = new NoOpTransport();
   const cdpConnectionAdapter = new CDPConnectionAdapter(cdp);
   const pptrTransport = {
@@ -53,7 +50,7 @@ export async function connectBidiOverCDP(
     // Forwards a BiDi event sent by BidiServer to Puppeteer.
     pptrTransport.onmessage(JSON.stringify(message));
   });
-  const pptrBiDiConnection = new BidiPPtrConnection(cdp.url(), pptrTransport);
+  const pptrBiDiConnection = new BidiConnection(cdp.url(), pptrTransport);
   const bidiServer = await BidiMapper.BidiServer.createAndStart(
     transportBiDi,
     cdpConnectionAdapter,
@@ -67,16 +64,16 @@ export async function connectBidiOverCDP(
  * @internal
  */
 class CDPConnectionAdapter {
-  #cdp: CDPPPtrConnection;
+  #cdp: CDPConnection;
   #adapters = new Map<CDPSession, CDPClientAdapter<CDPSession>>();
-  #browser: CDPClientAdapter<CDPPPtrConnection>;
+  #browser: CDPClientAdapter<CDPConnection>;
 
-  constructor(cdp: CDPPPtrConnection) {
+  constructor(cdp: CDPConnection) {
     this.#cdp = cdp;
     this.#browser = new CDPClientAdapter(cdp);
   }
 
-  browserClient(): CDPClientAdapter<CDPPPtrConnection> {
+  browserClient(): CDPClientAdapter<CDPConnection> {
     return this.#browser;
   }
 
@@ -107,8 +104,8 @@ class CDPConnectionAdapter {
  *
  * @internal
  */
-class CDPClientAdapter<T extends EventEmitter & Pick<CDPPPtrConnection, 'send'>>
+class CDPClientAdapter<T extends CDPSession | CDPConnection>
-  extends BidiMapper.EventEmitter<CdpEvents>
+  extends BidiMapper.EventEmitter<CDPEvents>
   implements BidiMapper.CdpClient
 {
   #closed = false;
@@ -132,9 +129,9 @@ class CDPClientAdapter<T extends EventEmitter & Pick<CDPPPtrConnection, 'send'>>
     return this.#browserClient!;
   }
 
-  #forwardMessage = <T extends keyof CdpEvents>(
+  #forwardMessage = <T extends keyof CDPEvents>(
     method: T,
-    event: CdpEvents[T]
+    event: CDPEvents[T]
   ) => {
     this.emit(method, event);
   };

packages/puppeteer-core/src/common/bidi/Browser.ts

@@ -21,21 +21,18 @@ import * as Bidi from 'chromium-bidi/lib/cjs/protocol/protocol.js';
 import {
   Browser,
   BrowserCloseCallback,
-  BrowserContextEmittedEvents,
   BrowserContextOptions,
-  BrowserEmittedEvents,
+  BrowserEvent,
 } from '../../api/Browser.js';
+import {BrowserContextEvent} from '../../api/BrowserContext.js';
 import {Page} from '../../api/Page.js';
 import {Target} from '../../api/Target.js';
 import {Handler} from '../EventEmitter.js';
 import {Viewport} from '../PuppeteerViewport.js';
 
 import {BidiBrowserContext} from './BrowserContext.js';
-import {
+import {BrowsingContext, BrowsingContextEvent} from './BrowsingContext.js';
-  BrowsingContext,
+import {BidiConnection} from './Connection.js';
-  BrowsingContextEmittedEvents,
-} from './BrowsingContext.js';
-import {Connection} from './Connection.js';
 import {
   BiDiBrowserTarget,
   BiDiBrowsingContextTarget,
@@ -44,6 +41,17 @@ import {
 } from './Target.js';
 import {debugError} from './utils.js';
 
+/**
+ * @internal
+ */
+interface Options {
+  process?: ChildProcess;
+  closeCallback?: BrowserCloseCallback;
+  connection: BidiConnection;
+  defaultViewport: Viewport | null;
+  ignoreHTTPSErrors?: boolean;
+}
+
 /**
  * @internal
  */
@@ -108,7 +116,7 @@ export class BidiBrowser extends Browser {
   #browserVersion = '';
   #process?: ChildProcess;
   #closeCallback?: BrowserCloseCallback;
-  #connection: Connection;
+  #connection: BidiConnection;
   #defaultViewport: Viewport | null;
   #defaultContext: BidiBrowserContext;
   #targets = new Map<string, BidiTarget>();
@@ -142,7 +150,7 @@ export class BidiBrowser extends Browser {
 
     this.#process?.once('close', () => {
       this.#connection.dispose();
-      this.emit(BrowserEmittedEvents.Disconnected);
+      this.emit(BrowserEvent.Disconnected, undefined);
     });
     this.#defaultContext = new BidiBrowserContext(this, {
       defaultViewport: this.#defaultViewport,
@@ -159,17 +167,15 @@ export class BidiBrowser extends Browser {
   #onContextDomLoaded(event: Bidi.BrowsingContext.Info) {
     const target = this.#targets.get(event.context);
     if (target) {
-      this.emit(BrowserEmittedEvents.TargetChanged, target);
+      this.emit(BrowserEvent.TargetChanged, target);
     }
   }
 
   #onContextNavigation(event: Bidi.BrowsingContext.NavigationInfo) {
     const target = this.#targets.get(event.context);
     if (target) {
-      this.emit(BrowserEmittedEvents.TargetChanged, target);
+      this.emit(BrowserEvent.TargetChanged, target);
-      target
+      target.browserContext().emit(BrowserContextEvent.TargetChanged, target);
-        .browserContext()
-        .emit(BrowserContextEmittedEvents.TargetChanged, target);
     }
   }
 
@@ -192,14 +198,12 @@ export class BidiBrowser extends Browser {
       : new BiDiBrowsingContextTarget(browserContext, context);
     this.#targets.set(event.context, target);
 
-    this.emit(BrowserEmittedEvents.TargetCreated, target);
+    this.emit(BrowserEvent.TargetCreated, target);
-    target
+    target.browserContext().emit(BrowserContextEvent.TargetCreated, target);
-      .browserContext()
-      .emit(BrowserContextEmittedEvents.TargetCreated, target);
 
     if (context.parent) {
       const topLevel = this.#connection.getTopLevelContext(context.parent);
-      topLevel.emit(BrowsingContextEmittedEvents.Created, context);
+      topLevel.emit(BrowsingContextEvent.Created, context);
     }
   }
 
@@ -215,20 +219,18 @@ export class BidiBrowser extends Browser {
   ) {
     const context = this.#connection.getBrowsingContext(event.context);
     const topLevelContext = this.#connection.getTopLevelContext(event.context);
-    topLevelContext.emit(BrowsingContextEmittedEvents.Destroyed, context);
+    topLevelContext.emit(BrowsingContextEvent.Destroyed, context);
     const target = this.#targets.get(event.context);
     const page = await target?.page();
     await page?.close().catch(debugError);
     this.#targets.delete(event.context);
     if (target) {
-      this.emit(BrowserEmittedEvents.TargetDestroyed, target);
+      this.emit(BrowserEvent.TargetDestroyed, target);
-      target
+      target.browserContext().emit(BrowserContextEvent.TargetDestroyed, target);
-        .browserContext()
-        .emit(BrowserContextEmittedEvents.TargetDestroyed, target);
     }
   }
 
-  get connection(): Connection {
+  get connection(): BidiConnection {
     return this.#connection;
   }
 
@@ -321,11 +323,3 @@ export class BidiBrowser extends Browser {
     return this.#browserTarget;
   }
 }
-
-interface Options {
-  process?: ChildProcess;
-  closeCallback?: BrowserCloseCallback;
-  connection: Connection;
-  defaultViewport: Viewport | null;
-  ignoreHTTPSErrors?: boolean;
-}

packages/puppeteer-core/src/common/bidi/BrowserContext.ts

@@ -22,7 +22,7 @@ import {Target} from '../../api/Target.js';
 import {Viewport} from '../PuppeteerViewport.js';
 
 import {BidiBrowser} from './Browser.js';
-import {Connection} from './Connection.js';
+import {BidiConnection} from './Connection.js';
 import {BidiPage} from './Page.js';
 
 interface BrowserContextOptions {
@@ -35,7 +35,7 @@ interface BrowserContextOptions {
  */
 export class BidiBrowserContext extends BrowserContext {
   #browser: BidiBrowser;
-  #connection: Connection;
+  #connection: BidiConnection;
   #defaultViewport: Viewport | null;
   #isDefault = false;
 
@@ -62,7 +62,7 @@ export class BidiBrowserContext extends BrowserContext {
     }, options);
   }
 
-  get connection(): Connection {
+  get connection(): BidiConnection {
     return this.#connection;
   }
 

packages/puppeteer-core/src/common/bidi/BrowsingContext.ts

@@ -1,15 +1,17 @@
 import * as Bidi from 'chromium-bidi/lib/cjs/protocol/protocol.js';
 import ProtocolMapping from 'devtools-protocol/types/protocol-mapping.js';
 
+import {CDPSession} from '../../api/CDPSession.js';
 import {WaitForOptions} from '../../api/Page.js';
 import {assert} from '../../util/assert.js';
 import {Deferred} from '../../util/Deferred.js';
-import {Connection as CDPConnection, CDPSession} from '../Connection.js';
+import {Connection as CDPConnection} from '../Connection.js';
 import {ProtocolError, TargetCloseError, TimeoutError} from '../Errors.js';
+import {EventType} from '../EventEmitter.js';
 import {PuppeteerLifeCycleEvent} from '../LifecycleWatcher.js';
 import {setPageContent, waitWithTimeout} from '../util.js';
 
-import {Connection} from './Connection.js';
+import {BidiConnection} from './Connection.js';
 import {Realm} from './Realm.js';
 import {debugError} from './utils.js';
 
@@ -120,17 +122,26 @@ export class CDPSessionWrapper extends CDPSession {
  *
  * @internal
  */
-export const BrowsingContextEmittedEvents = {
+// eslint-disable-next-line @typescript-eslint/no-namespace
+export namespace BrowsingContextEvent {
   /**
    * Emitted on the top-level context, when a descendant context is created.
    */
-  Created: Symbol('BrowsingContext.created'),
+  export const Created = Symbol('BrowsingContext.created');
   /**
    * Emitted on the top-level context, when a descendant context or the
    * top-level context itself is destroyed.
    */
-  Destroyed: Symbol('BrowsingContext.destroyed'),
+  export const Destroyed = Symbol('BrowsingContext.destroyed');
-} as const;
+}
+
+/**
+ * @internal
+ */
+export interface BrowsingContextEvents extends Record<EventType, unknown> {
+  [BrowsingContextEvent.Created]: BrowsingContext;
+  [BrowsingContextEvent.Destroyed]: BrowsingContext;
+}
 
 /**
  * @internal
@@ -143,7 +154,7 @@ export class BrowsingContext extends Realm {
   #browserName = '';
 
   constructor(
-    connection: Connection,
+    connection: BidiConnection,
     info: Bidi.BrowsingContext.Info,
     browserName: string
   ) {

packages/puppeteer-core/src/common/bidi/Connection.test.ts

@@ -20,7 +20,7 @@ import expect from 'expect';
 
 import {ConnectionTransport} from '../ConnectionTransport.js';
 
-import {Connection} from './Connection.js';
+import {BidiConnection} from './Connection.js';
 
 describe('WebDriver BiDi Connection', () => {
   class TestConnectionTransport implements ConnectionTransport {
@@ -38,7 +38,7 @@ describe('WebDriver BiDi Connection', () => {
 
   it('should work', async () => {
     const transport = new TestConnectionTransport();
-    const connection = new Connection('ws://127.0.0.1', transport);
+    const connection = new BidiConnection('ws://127.0.0.1', transport);
     const responsePromise = connection.send('session.new', {
       capabilities: {},
     });
@@ -48,6 +48,7 @@ describe('WebDriver BiDi Connection', () => {
     const id = JSON.parse(transport.sent[0]!).id;
     const rawResponse = {
       id,
+      type: 'success',
       result: {ready: false, message: 'already connected'},
     };
     (transport as ConnectionTransport).onmessage?.(JSON.stringify(rawResponse));

packages/puppeteer-core/src/common/bidi/Connection.ts

@@ -127,7 +127,17 @@ interface Commands {
 /**
  * @internal
  */
-export class Connection extends EventEmitter {
+export type BidiEvents = {
+  [K in Bidi.ChromiumBidi.Event['method']]: Extract<
+    Bidi.ChromiumBidi.Event,
+    {method: K}
+  >['params'];
+};
+
+/**
+ * @internal
+ */
+export class BidiConnection extends EventEmitter<BidiEvents> {
   #url: string;
   #transport: ConnectionTransport;
   #delay: number;
@@ -185,35 +195,45 @@ export class Connection extends EventEmitter {
       });
     }
     debugProtocolReceive(message);
-    const object = JSON.parse(message) as Bidi.ChromiumBidi.Message;
+    const object: Bidi.ChromiumBidi.Message = JSON.parse(message);
-
+    if ('type' in object) {
-    if ('id' in object && object.id) {
+      switch (object.type) {
-      if ('error' in object) {
+        case 'success':
+          this.#callbacks.resolve(object.id, object);
+          return;
+        case 'error':
+          if (object.id === null) {
+            break;
+          }
           this.#callbacks.reject(
             object.id,
-          createProtocolError(object as Bidi.ErrorResponse),
+            createProtocolError(object),
             object.message
           );
-      } else {
+          return;
-        this.#callbacks.resolve(object.id, object);
+        case 'event':
-      }
-    } else {
-      if ('error' in object || 'id' in object || 'launched' in object) {
-        debugError(object);
-      } else {
           this.#maybeEmitOnContext(object);
-        this.emit(object.method, object.params);
+          // SAFETY: We know the method and parameter still match here.
+          this.emit(
+            object.method,
+            object.params as BidiEvents[keyof BidiEvents]
+          );
+          return;
       }
     }
+    debugError(object);
   }
 
   #maybeEmitOnContext(event: Bidi.ChromiumBidi.Event) {
     let context: BrowsingContext | undefined;
     // Context specific events
-    if ('context' in event.params && event.params.context) {
+    if ('context' in event.params && event.params.context !== null) {
       context = this.#browsingContexts.get(event.params.context);
       // `log.entryAdded` specific context
-    } else if ('source' in event.params && event.params.source.context) {
+    } else if (
+      'source' in event.params &&
+      event.params.source.context !== undefined
+    ) {
       context = this.#browsingContexts.get(event.params.source.context);
     } else if (isCDPEvent(event)) {
       cdpSessions

packages/puppeteer-core/src/common/bidi/ExposedFunction.ts

@@ -21,7 +21,7 @@ import {Deferred} from '../../util/Deferred.js';
 import {interpolateFunction, stringifyFunction} from '../../util/Function.js';
 import {Awaitable, FlattenHandle} from '../types.js';
 
-import {Connection} from './Connection.js';
+import {BidiConnection} from './Connection.js';
 import {BidiFrame} from './Frame.js';
 import {BidiSerializer} from './Serializer.js';
 import {debugError} from './utils.js';
@@ -39,6 +39,9 @@ interface RemotePromiseCallbacks {
   reject: Deferred<Bidi.Script.RemoteValue>;
 }
 
+/**
+ * @internal
+ */
 export class ExposeableFunction<Args extends unknown[], Ret> {
   readonly #frame;
 
@@ -200,7 +203,7 @@ export class ExposeableFunction<Args extends unknown[], Ret> {
     }
   };
 
-  get #connection(): Connection {
+  get #connection(): BidiConnection {
     return this.#frame.context().connection;
   }
 

packages/puppeteer-core/src/common/bidi/Frame.ts

@@ -16,9 +16,9 @@
 
 import * as Bidi from 'chromium-bidi/lib/cjs/protocol/protocol.js';
 
+import {CDPSession} from '../../api/CDPSession.js';
 import {Frame, throwIfDetached} from '../../api/Frame.js';
 import {Deferred} from '../../util/Deferred.js';
-import {CDPSession} from '../Connection.js';
 import {UTILITY_WORLD_NAME} from '../FrameManager.js';
 import {PuppeteerLifeCycleEvent} from '../LifecycleWatcher.js';
 import {TimeoutSettings} from '../TimeoutSettings.js';
@@ -31,7 +31,7 @@ import {
   lifeCycleToSubscribedEvent,
 } from './BrowsingContext.js';
 import {ExposeableFunction} from './ExposedFunction.js';
-import {HTTPResponse} from './HTTPResponse.js';
+import {BidiHTTPResponse} from './HTTPResponse.js';
 import {BidiPage} from './Page.js';
 import {
   MAIN_SANDBOX,
@@ -114,7 +114,7 @@ export class BidiFrame extends Frame {
       timeout?: number;
       waitUntil?: PuppeteerLifeCycleEvent | PuppeteerLifeCycleEvent[];
     }
-  ): Promise<HTTPResponse | null> {
+  ): Promise<BidiHTTPResponse | null> {
     const navigationId = await this.#context.goto(url, {
       ...options,
       timeout: options?.timeout ?? this.#timeoutSettings.navigationTimeout(),
@@ -146,7 +146,7 @@ export class BidiFrame extends Frame {
       timeout?: number;
       waitUntil?: PuppeteerLifeCycleEvent | PuppeteerLifeCycleEvent[];
     } = {}
-  ): Promise<HTTPResponse | null> {
+  ): Promise<BidiHTTPResponse | null> {
     const {
       waitUntil = 'load',
       timeout = this.#timeoutSettings.navigationTimeout(),