fix: revert ExecutionContext reporting. (#3058)

It turned out that almost any usecase requires helper methods to access
DOM inside the ExecutionContext.

Instead of exposing execution contexts as-is, we should introduce
IsolatedWorld as a first-class citizen that will hold execution contexts
inside.

docs/api.md

@@ -59,8 +59,6 @@ Next Release: **Aug 9, 2018**
   * [event: 'dialog'](#event-dialog)
   * [event: 'domcontentloaded'](#event-domcontentloaded)
   * [event: 'error'](#event-error)
-  * [event: 'executioncontextcreated'](#event-executioncontextcreated)
-  * [event: 'executioncontextdestroyed'](#event-executioncontextdestroyed)
   * [event: 'frameattached'](#event-frameattached)
   * [event: 'framedetached'](#event-framedetached)
   * [event: 'framenavigated'](#event-framenavigated)
@@ -183,7 +181,6 @@ Next Release: **Aug 9, 2018**
   * [frame.evaluate(pageFunction, ...args)](#frameevaluatepagefunction-args)
   * [frame.evaluateHandle(pageFunction, ...args)](#frameevaluatehandlepagefunction-args)
   * [frame.executionContext()](#frameexecutioncontext)
-  * [frame.executionContexts()](#frameexecutioncontexts)
   * [frame.focus(selector)](#framefocusselector)
   * [frame.hover(selector)](#framehoverselector)
   * [frame.isDetached()](#frameisdetached)
@@ -203,8 +200,6 @@ Next Release: **Aug 9, 2018**
   * [executionContext.evaluate(pageFunction, ...args)](#executioncontextevaluatepagefunction-args)
   * [executionContext.evaluateHandle(pageFunction, ...args)](#executioncontextevaluatehandlepagefunction-args)
   * [executionContext.frame()](#executioncontextframe)
-  * [executionContext.isDefault()](#executioncontextisdefault)
-  * [executionContext.name()](#executioncontextname)
   * [executionContext.queryObjects(prototypeHandle)](#executioncontextqueryobjectsprototypehandle)
 - [class: JSHandle](#class-jshandle)
   * [jsHandle.asElement()](#jshandleaselement)
@@ -804,16 +799,6 @@ Emitted when the page crashes.
 
 > **NOTE** `error` event has a special meaning in Node, see [error events](https://nodejs.org/api/events.html#events_error_events) for details.
 
-#### event: 'executioncontextcreated'
-- <[ExecutionContext]>
-
-Emitted whenever an execution context is created in one of the page's frames.
-
-#### event: 'executioncontextdestroyed'
-- <[ExecutionContext]>
-
-Emitted whenever an execution context is removed from one of the page's frames.
-
 #### event: 'frameattached'
 - <[Frame]>
 
@@ -2248,11 +2233,6 @@ await resultHandle.dispose();
 
 Returns promise that resolves to the frame's default execution context.
 
-#### frame.executionContexts()
-- returns: <[Array]<[ExecutionContext]>>
-
-Returns all execution contexts associated with this frame.
-
 #### frame.focus(selector)
 - `selector` <[string]> A [selector] of an element to focus. If there are multiple elements satisfying the selector, the first will be focused.
 - returns: <[Promise]> Promise which resolves when the element matching `selector` is successfully focused. The promise will be rejected if there is no element matching `selector`.
@@ -2452,11 +2432,7 @@ puppeteer.launch().then(async browser => {
 The class represents a context for JavaScript execution. A [Page] might have many execution contexts:
 - each [frame](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe) has "default" execution context that is
   always created after frame is attached to DOM. This context is returned by the [`frame.executionContext()`](#frameexecutioncontext) method.
-- [Extensions](https://developer.chrome.com/extensions)'s content scripts create additional execution contexts. These execution
+- [Extensions](https://developer.chrome.com/extensions)'s content scripts create additional execution contexts.
-  contexts can be obtained via the [`frame.executionContexts()`](#frameexecutioncontexts) method.
-
-The execution context lifecycle can be observed with [Page]'s ['executioncontextcreated'](#event-executioncontextcreated) and
-['executioncontextdestroyed'](#event-executioncontextdestroyed) events.
 
 Besides pages, execution contexts can be found in [workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API).
 
@@ -2525,19 +2501,6 @@ await resultHandle.dispose();
 > **NOTE** Not every execution context is associated with a frame. For example, workers and extensions have execution contexts that are not associated with frames.
 
 
-#### executionContext.isDefault()
-- returns: <[boolean]>
-
-Returns `true` if the execution context is a frame's main execution context; returns `false` otherwise.
-
-
-#### executionContext.name()
-- returns: <[string]>
-
-Returns execution context name, if any. If this execution context is associated with Chrome Extension's content
-script, this will return extension's name.
-
-
 #### executionContext.queryObjects(prototypeHandle)
 - `prototypeHandle` <[JSHandle]> A handle to the object prototype.
 - returns: <[JSHandle]> A handle to an array of objects with this prototype

lib/ExecutionContext.js

@@ -31,24 +31,9 @@ class ExecutionContext {
     this._frame = frame;
     this._contextId = contextPayload.id;
     this._isDefault = contextPayload.auxData ? !!contextPayload.auxData['isDefault'] : false;
-    this._name = contextPayload.name;
     this._objectHandleFactory = objectHandleFactory;
   }
 
-  /**
-   * @return {string}
-   */
-  name() {
-    return this._name;
-  }
-
-  /**
-   * @return {boolean}
-   */
-  isDefault() {
-    return this._isDefault;
-  }
-
   /**
    * @return {?Puppeteer.Frame}
    */

lib/FrameManager.js

@@ -188,7 +188,6 @@ class FrameManager extends EventEmitter {
     this._contextIdToContext.set(contextPayload.id, context);
     if (frame)
       frame._addExecutionContext(context);
-    this.emit(FrameManager.Events.ExecutionContextCreated, context);
   }
 
   /**
@@ -201,18 +200,14 @@ class FrameManager extends EventEmitter {
     this._contextIdToContext.delete(executionContextId);
     if (context.frame())
       context.frame()._removeExecutionContext(context);
-    this.emit(FrameManager.Events.ExecutionContextDestroyed, context);
   }
 
   _onExecutionContextsCleared() {
-    const contexts = Array.from(this._contextIdToContext.values());
+    for (const context of this._contextIdToContext.values()) {
-    this._contextIdToContext.clear();
-    for (const context of contexts) {
       if (context.frame())
         context.frame()._removeExecutionContext(context);
     }
-    for (const context of contexts)
+    this._contextIdToContext.clear();
-      this.emit(FrameManager.Events.ExecutionContextDestroyed, context);
   }
 
   /**
@@ -281,8 +276,6 @@ class Frame {
     this._contextResolveCallback = null;
     this._setDefaultContext(null);
 
-    this._executionContexts = new Set();
-
     /** @type {!Set<!WaitTask>} */
     this._waitTasks = new Set();
     this._loaderId = '';
@@ -299,8 +292,7 @@ class Frame {
    * @param {!ExecutionContext} context
    */
   _addExecutionContext(context) {
-    this._executionContexts.add(context);
+    if (context._isDefault)
-    if (context.isDefault())
       this._setDefaultContext(context);
   }
 
@@ -308,8 +300,7 @@ class Frame {
    * @param {!ExecutionContext} context
    */
   _removeExecutionContext(context) {
-    this._executionContexts.delete(context);
+    if (context._isDefault)
-    if (context.isDefault())
       this._setDefaultContext(null);
   }
 
@@ -337,13 +328,6 @@ class Frame {
     return this._contextPromise;
   }
 
-  /**
-   * @return {!Array<!ExecutionContext>}
-   */
-  executionContexts() {
-    return Array.from(this._executionContexts);
-  }
-
   /**
    * @param {function()|string} pageFunction
    * @param {!Array<*>} args

lib/Page.js

@@ -121,8 +121,6 @@ class Page extends EventEmitter {
     this._frameManager.on(FrameManager.Events.FrameAttached, event => this.emit(Page.Events.FrameAttached, event));
     this._frameManager.on(FrameManager.Events.FrameDetached, event => this.emit(Page.Events.FrameDetached, event));
     this._frameManager.on(FrameManager.Events.FrameNavigated, event => this.emit(Page.Events.FrameNavigated, event));
-    this._frameManager.on(FrameManager.Events.ExecutionContextCreated, event => this.emit(Page.Events.ExecutionContextCreated, event));
-    this._frameManager.on(FrameManager.Events.ExecutionContextDestroyed, event => this.emit(Page.Events.ExecutionContextDestroyed, event));
 
     this._networkManager.on(NetworkManager.Events.Request, event => this.emit(Page.Events.Request, event));
     this._networkManager.on(NetworkManager.Events.Response, event => this.emit(Page.Events.Response, event));
@@ -1130,8 +1128,6 @@ Page.Events = {
   Metrics: 'metrics',
   WorkerCreated: 'workercreated',
   WorkerDestroyed: 'workerdestroyed',
-  ExecutionContextCreated: 'executioncontextcreated',
-  ExecutionContextDestroyed: 'executioncontextdestroyed',
 };
 
 

test/headful.spec.js

@@ -117,27 +117,6 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions})
       ]);
       await browser.close();
     });
-    it('should report content script execution contexts', async({server}) => {
-      const browserWithExtension = await puppeteer.launch(extensionOptions);
-      const page = await browserWithExtension.newPage();
-      const [extensionContext, msg] = await Promise.all([
-        waitEvent(page, 'executioncontextcreated', context => !context.isDefault()),
-        waitEvent(page, 'console'),
-        page.goto(server.EMPTY_PAGE)
-      ]);
-      expect(msg.text()).toBe('hey from the content-script');
-      expect(page.mainFrame().executionContexts().length).toBe(2);
-      expect(extensionContext.frame()).toBe(page.mainFrame());
-      expect(extensionContext.name()).toBe('Simple extension');
-      expect(await extensionContext.evaluate('thisIsTheContentScript')).toBe(true);
-
-      const [destroyedContext] = await Promise.all([
-        waitEvent(page, 'executioncontextdestroyed', context => !context.isDefault()),
-        page.reload()
-      ]);
-      expect(destroyedContext).toBe(extensionContext);
-      await browserWithExtension.close();
-    });
   });
 };
 

test/page.spec.js

@@ -80,11 +80,6 @@ module.exports.addTests = function({testRunner, expect, headless}) {
       const result = await page.evaluate(() => 7 * 3);
       expect(result).toBe(21);
     });
-    it('should have nice default execution context', async({page, server}) => {
-      const executionContext = await page.mainFrame().executionContext();
-      expect(executionContext.name()).toBe('');
-      expect(executionContext.isDefault()).toBe(true);
-    });
     it('should throw when evaluation triggers reload', async({page, server}) => {
       let error = null;
       await page.evaluate(() => {