chore: add basic screenshot to BiDi (#9923)

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

@@ -58,7 +58,7 @@ import type {
   HandleFor,
   NodeFor,
 } from '../common/types.js';
-import {isNumber, isString} from '../common/util.js';
+import {importFSPromises, isNumber, isString} from '../common/util.js';
 import type {WebWorker} from '../common/WebWorker.js';
 import {assert} from '../util/assert.js';
 
@@ -2083,6 +2083,31 @@ export class Page extends EventEmitter {
     throw new Error('Not implemented');
   }
 
+  /**
+   * @internal
+   */
+  async _maybeWriteBufferToFile(
+    path: string | undefined,
+    buffer: Buffer
+  ): Promise<void> {
+    if (!path) {
+      return;
+    }
+
+    try {
+      const fs = await importFSPromises();
+
+      await fs.writeFile(path, buffer);
+    } catch (error) {
+      if (error instanceof TypeError) {
+        throw new Error(
+          'Can only pass a file path in a Node-like environment.'
+        );
+      }
+      throw error;
+    }
+  }
+
   /**
    * @remarks
    * Options object which might have the following properties:

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

@@ -91,7 +91,6 @@ import {
   getExceptionMessage,
   getReadableAsBuffer,
   getReadableFromProtocolStream,
-  importFSPromises,
   isString,
   pageBindingInitString,
   releaseObject,
@@ -1440,24 +1439,13 @@ export class CDPPage extends Page {
       await this.setViewport(this.#viewport);
     }
 
-    const buffer =
+    if (options.encoding === 'base64') {
-      options.encoding === 'base64'
+      return result.data;
-        ? result.data
-        : Buffer.from(result.data, 'base64');
-
-    if (options.path) {
-      try {
-        const fs = await importFSPromises();
-        await fs.writeFile(options.path, buffer);
-      } catch (error) {
-        if (error instanceof TypeError) {
-          throw new Error(
-            'Screenshots can only be written to a file path in a Node-like environment.'
-          );
-        }
-        throw error;
-      }
     }
+
+    const buffer = Buffer.from(result.data, 'base64');
+    await this._maybeWriteBufferToFile(options.path, buffer);
+
     return buffer;
 
     function processClip(clip: ScreenshotClip): ScreenshotClip {

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

@@ -59,6 +59,10 @@ interface Commands {
     params: Bidi.BrowsingContext.PrintParameters;
     returnType: Bidi.BrowsingContext.PrintResult;
   };
+  'browsingContext.captureScreenshot': {
+    params: Bidi.BrowsingContext.CaptureScreenshotParameters;
+    returnType: Bidi.BrowsingContext.CaptureScreenshotResult;
+  };
 
   'session.new': {
     params: {capabilities?: Record<any, unknown>}; // TODO: Update Types in chromium bidi

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

@@ -22,6 +22,7 @@ import {HTTPResponse} from '../../api/HTTPResponse.js';
 import {
   Page as PageBase,
   PageEmittedEvents,
+  ScreenshotOptions,
   WaitForOptions,
 } from '../../api/Page.js';
 import {isErrorLike} from '../../util/ErrorLike.js';
@@ -29,7 +30,7 @@ import {ConsoleMessage, ConsoleMessageLocation} from '../ConsoleMessage.js';
 import {Handler} from '../EventEmitter.js';
 import {PDFOptions} from '../PDFOptions.js';
 import {EvaluateFunc, HandleFor} from '../types.js';
-import {debugError, importFSPromises, waitWithTimeout} from '../util.js';
+import {debugError, waitWithTimeout} from '../util.js';
 
 import {Context, getBidiHandle} from './Context.js';
 import {BidiSerializer} from './Serializer.js';
@@ -226,20 +227,7 @@ export class Page extends PageBase {
 
     const buffer = Buffer.from(result.data, 'base64');
 
-    try {
+    await this._maybeWriteBufferToFile(path, buffer);
-      if (path) {
-        const fs = await importFSPromises();
-
-        await fs.writeFile(path, buffer);
-      }
-    } catch (error) {
-      if (error instanceof TypeError) {
-        throw new Error(
-          'Can only pass a file path in a Node-like environment.'
-        );
-      }
-      throw error;
-    }
 
     return buffer;
   }
@@ -260,6 +248,37 @@ export class Page extends PageBase {
       throw error;
     }
   }
+
+  override screenshot(
+    options: ScreenshotOptions & {encoding: 'base64'}
+  ): Promise<string>;
+  override screenshot(
+    options?: ScreenshotOptions & {encoding?: 'binary'}
+  ): never;
+  override async screenshot(
+    options: ScreenshotOptions = {}
+  ): Promise<Buffer | string> {
+    const {path = undefined, encoding, ...args} = options;
+    if (Object.keys(args).length >= 1) {
+      throw new Error('BiDi only supports "encoding" and "path" options');
+    }
+
+    const {result} = await this.#context.connection.send(
+      'browsingContext.captureScreenshot',
+      {
+        context: this.#context._contextId,
+      }
+    );
+
+    if (encoding === 'base64') {
+      return result.data;
+    }
+
+    const buffer = Buffer.from(result.data, 'base64');
+    await this._maybeWriteBufferToFile(path, buffer);
+
+    return buffer;
+  }
 }
 
 function isConsoleLogEntry(