feat(launcher): add experimental "transport" option to pptr.connect (#3265)

This patch:
- adds experimental "transport" option to pptr.connect
- uses "transport" option to make sure Puppeteer-Web works with
  Target.exposeDevToolsProtocol

Drive-by: add `browser.target()` to access browser target.

docs/api.md

@@ -48,6 +48,7 @@
   * [browser.newPage()](#browsernewpage)
   * [browser.pages()](#browserpages)
   * [browser.process()](#browserprocess)
+  * [browser.target()](#browsertarget)
   * [browser.targets()](#browsertargets)
   * [browser.userAgent()](#browseruseragent)
   * [browser.version()](#browserversion)
@@ -677,6 +678,11 @@ the method will return an array with all the pages in all browser contexts.
 #### browser.process()
 - returns: <?[ChildProcess]> Spawned browser process. Returns `null` if the browser instance was created with [`puppeteer.connect`](#puppeteerconnectoptions) method.
 
+#### browser.target()
+- returns: <[Target]>
+
+A target associated with the browser.
+
 #### browser.targets()
 - returns: <[Array]<[Target]>>
 

lib/Browser.js

@@ -185,6 +185,13 @@ class Browser extends EventEmitter {
     return Array.from(this._targets.values()).filter(target => target._isInitialized);
   }
 
+  /**
+   * @return {!Target}
+   */
+  target() {
+    return this.targets().find(target => target.type() === 'browser');
+  }
+
   /**
    * @return {!Promise<!Array<!Puppeteer.Page>>}
    */

lib/Launcher.js

@@ -270,7 +270,7 @@ class Launcher {
   }
 
   /**
-   * @param {!(BrowserOptions & {browserWSEndpoint: string})} options
+   * @param {!(BrowserOptions & {browserWSEndpoint: string, transport?: !Puppeteer.ConnectionTransport})} options
    * @return {!Promise<!Browser>}
    */
   async connect(options) {
@@ -278,9 +278,9 @@ class Launcher {
       browserWSEndpoint,
       ignoreHTTPSErrors = false,
       defaultViewport = {width: 800, height: 600},
+      transport = await WebSocketTransport.create(browserWSEndpoint),
       slowMo = 0,
     } = options;
-    const transport = await WebSocketTransport.create(browserWSEndpoint);
     const connection = new Connection(browserWSEndpoint, transport, slowMo);
     const {browserContextIds} = await connection.send('Target.getBrowserContexts');
     return Browser.create(connection, browserContextIds, ignoreHTTPSErrors, defaultViewport, null, () => connection.send('Browser.close').catch(debugError));

lib/Puppeteer.js

@@ -37,7 +37,7 @@ module.exports = class {
   }
 
   /**
-   * @param {{browserWSEndpoint: string, ignoreHTTPSErrors: boolean}} options
+   * @param {{browserWSEndpoint: string, ignoreHTTPSErrors: boolean, transport?: !Puppeteer.ConnectionTransport}} options
    * @return {!Promise<!Puppeteer.Browser>}
    */
   connect(options) {

test/browser.spec.js

@@ -37,6 +37,13 @@ module.exports.addTests = function({testRunner, expect, headless}) {
     });
   });
 
+  describe('Browser.target', function() {
+    it('should return browser target', async({browser}) => {
+      const target = browser.target();
+      expect(target.type()).toBe('browser');
+    });
+  });
+
   describe('Browser.process', function() {
     it('should return child_process instance', async function({browser}) {
       const process = await browser.process();

utils/ESTreeWalker.js

@@ -80,6 +80,7 @@ ESTreeWalker._walkOrder = {
   'ArrayExpression': ['elements'],
   'ArrowFunctionExpression': ['params', 'body'],
   'AssignmentExpression': ['left', 'right'],
+  'AssignmentPattern': ['left', 'right'],
   'BinaryExpression': ['left', 'right'],
   'BlockStatement': ['body'],
   'BreakStatement': ['label'],

utils/browser/test.js

@@ -69,6 +69,28 @@ describe('Puppeteer-Web', () => {
     ]);
     await browser2.close();
   });
+  it('should work over exposed DevTools protocol', async({browser, page, serverConfig}) => {
+    // Expose devtools protocol binding into page.
+    const session = await browser.target().createCDPSession();
+    const pageInfo = (await session.send('Target.getTargets')).targetInfos.find(info => info.attached);
+    await session.send('Target.exposeDevToolsProtocol', {targetId: pageInfo.targetId});
+    await session.detach();
+
+    // Use in-page puppeteer to create a new page and navigate it to the EMPTY_PAGE
+    await page.evaluate(async serverConfig  => {
+      const puppeteer = require('puppeteer');
+      window.cdp.close = () => {};
+      const browser = await puppeteer.connect({transport: window.cdp});
+      const page = await browser.newPage();
+      await page.goto(serverConfig.EMPTY_PAGE);
+    }, serverConfig);
+    const pageURLs = (await browser.pages()).map(page => page.url()).sort();
+    expect(pageURLs).toEqual([
+      'about:blank',
+      'about:blank',
+      serverConfig.EMPTY_PAGE
+    ]);
+  });
 });
 
 if (process.env.CI && testRunner.hasFocusedTestsOrSuites()) {