feat(api): introduce BrowserContext.waitForEvent

Author: yury-s

docs/api.md

@@ -291,6 +291,7 @@ await context.close();
 - [browserContext.setGeolocation(geolocation)](#browsercontextsetgeolocationgeolocation)
 - [browserContext.setOffline(offline)](#browsercontextsetofflineoffline)
 - [browserContext.setPermissions(origin, permissions[])](#browsercontextsetpermissionsorigin-permissions)
+- [browserContext.waitForEvent(event[, optionsOrPredicate])](#browsercontextwaitforeventevent-optionsorpredicate)
 <!-- GEN:stop -->
 
 #### event: 'close'
@@ -545,6 +546,15 @@ await browserContext.setGeolocation({latitude: 59.95, longitude: 30.31667});
     - `'payment-handler'`
 - returns: <[Promise]>
 
+#### browserContext.waitForEvent(event[, optionsOrPredicate])
+- `event` <[string]> Event name, same one would pass into `browserContext.on(event)`.
+- `optionsOrPredicate` <[Function]|[Object]> Either a predicate that receives an event or an options object.
+  - `predicate` <[Function]> receives the event data and resolves to truthy value when the waiting should resolve.
+  - `timeout` <[number]> maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout. The default value can be changed by using the [browserContext.setDefaultTimeout(timeout)](#browsercontextsetdefaulttimeouttimeout).
+- returns: <[Promise]<[any]>> Promise which resolves to the event data value.
+
+Waits for event to fire and passes its value into the predicate function. Resolves when the predicate returns truthy value. Will throw an error if the context closes before the event
+is fired.
 
 ```js
 const context = await browser.newContext();
@@ -1611,13 +1621,11 @@ Shortcut for [page.mainFrame().waitFor(selectorOrFunctionOrTimeout[, options[, .
 - `event` <[string]> Event name, same one would pass into `page.on(event)`.
 - `optionsOrPredicate` <[Function]|[Object]> Either a predicate that receives an event or an options object.
   - `predicate` <[Function]> receives the event data and resolves to truthy value when the waiting should resolve.
-  - `polling` <[number]|"raf"|"mutation"> An interval at which the `pageFunction` is executed, defaults to `raf`. If `polling` is a number, then it is treated as an interval in milliseconds at which the function would be executed. If `polling` is a string, then it can be one of the following values:
-    - `'raf'` - to constantly execute `pageFunction` in `requestAnimationFrame` callback. This is the tightest polling mode which is suitable to observe styling changes.
-    - `'mutation'` - to execute `pageFunction` on every DOM mutation.
   - `timeout` <[number]> maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout. The default value can be changed by using the [browserContext.setDefaultTimeout(timeout)](#browsercontextsetdefaulttimeouttimeout) or [page.setDefaultTimeout(timeout)](#pagesetdefaulttimeouttimeout) methods.
 - returns: <[Promise]<[any]>> Promise which resolves to the event data value.
 
-Waits for event to fire and passes its value into the predicate function. Resolves when the predicate returns truthy value.
+Waits for event to fire and passes its value into the predicate function. Resolves when the predicate returns truthy value. Will throw an error if the page is closed before the event
+is fired.
 
 #### page.waitForFunction(pageFunction[, options[, ...args]])
 - `pageFunction` <[function]|[string]> Function to be evaluated in browser context
@@ -3729,6 +3737,7 @@ const backgroundPage = await backroundPageTarget.page();
 - [browserContext.setGeolocation(geolocation)](#browsercontextsetgeolocationgeolocation)
 - [browserContext.setOffline(offline)](#browsercontextsetofflineoffline)
 - [browserContext.setPermissions(origin, permissions[])](#browsercontextsetpermissionsorigin-permissions)
+- [browserContext.waitForEvent(event[, optionsOrPredicate])](#browsercontextwaitforeventevent-optionsorpredicate)
 <!-- GEN:stop -->
 
 #### event: 'backgroundpage'

src/browserContext.ts

@@ -15,11 +15,13 @@
  * limitations under the License.
  */
 
-import { Page, PageBinding } from './page';
-import * as network from './network';
-import * as types from './types';
 import { helper } from './helper';
+import * as network from './network';
+import { Page, PageBinding } from './page';
+import * as platform from './platform';
 import { TimeoutSettings } from './timeoutSettings';
+import * as types from './types';
+import { Events } from './events';
 
 export type BrowserContextOptions = {
   viewport?: types.Viewport | null,
@@ -50,15 +52,69 @@ export interface BrowserContext {
   setOffline(offline: boolean): Promise<void>;
   addInitScript(script: Function | string | { path?: string, content?: string }, ...args: any[]): Promise<void>;
   exposeFunction(name: string, playwrightFunction: Function): Promise<void>;
+  waitForEvent(event: string, optionsOrPredicate?: Function | (types.TimeoutOptions & { predicate?: Function })): Promise<any>;
   close(): Promise<void>;
+}
 
-  _existingPages(): Page[];
-  readonly _timeoutSettings: TimeoutSettings;
+export abstract class BrowserContextBase extends platform.EventEmitter implements BrowserContext {
+  readonly _timeoutSettings = new TimeoutSettings();
+  readonly _pageBindings = new Map<string, PageBinding>();
   readonly _options: BrowserContextOptions;
-  readonly _pageBindings: Map<string, PageBinding>;
+  private _closePromise: Promise<Error> | undefined;
+
+  constructor(options: BrowserContextOptions) {
+    super();
+    this._options = options;
+  }
+
+  abstract _existingPages(): Page[];
+
+  // BrowserContext methods.
+  abstract pages(): Promise<Page[]>;
+  abstract newPage(): Promise<Page>;
+  abstract cookies(...urls: string[]): Promise<network.NetworkCookie[]>;
+  abstract setCookies(cookies: network.SetNetworkCookieParam[]): Promise<void>;
+  abstract clearCookies(): Promise<void>;
+  abstract setPermissions(origin: string, permissions: string[]): Promise<void>;
+  abstract clearPermissions(): Promise<void>;
+  abstract setGeolocation(geolocation: types.Geolocation | null): Promise<void>;
+  abstract setExtraHTTPHeaders(headers: network.Headers): Promise<void>;
+  abstract setOffline(offline: boolean): Promise<void>;
+  abstract addInitScript(script: string | Function | { path?: string | undefined; content?: string | undefined; }, ...args: any[]): Promise<void>;
+  abstract exposeFunction(name: string, playwrightFunction: Function): Promise<void>;
+  abstract close(): Promise<void>;
+
+  setDefaultNavigationTimeout(timeout: number) {
+    this._timeoutSettings.setDefaultNavigationTimeout(timeout);
+  }
+
+  setDefaultTimeout(timeout: number) {
+    this._timeoutSettings.setDefaultTimeout(timeout);
+  }
+
+  async waitForEvent(event: string, optionsOrPredicate?: Function | (types.TimeoutOptions & { predicate?: Function })): Promise<any> {
+    if (!optionsOrPredicate)
+      optionsOrPredicate = {};
+    if (typeof optionsOrPredicate === 'function')
+      optionsOrPredicate = { predicate: optionsOrPredicate };
+    const { timeout = this._timeoutSettings.timeout(), predicate = () => true } = optionsOrPredicate;
+
+    let abortPromise: Promise<Error>;
+    if (event === Events.BrowserContext.Close) {
+      abortPromise = new Promise<Error>(() => { });
+    } else {
+      if (!this._closePromise) {
+        this._closePromise = new Promise(fulfill => {
+          this.once(Events.BrowserContext.Close, () => fulfill(new Error('Context closed')));
+        });
+      }
+      abortPromise = this._closePromise;
+    }
+    return helper.waitForEvent(this, event, (...args: any[]) => !!predicate(...args), timeout, abortPromise);
+  }
 }
 
-export function assertBrowserContextIsNotOwned(context: BrowserContext) {
+export function assertBrowserContextIsNotOwned(context: BrowserContextBase) {
   const pages = context._existingPages();
   for (const page of pages) {
     if (page._ownedContext)

src/chromium/crBrowser.ts

@@ -15,22 +15,21 @@
  * limitations under the License.
  */
 
-import { Events } from './events';
-import { Events as CommonEvents } from '../events';
-import { assert, helper, debugError } from '../helper';
-import { BrowserContext, BrowserContextOptions, validateBrowserContextOptions, assertBrowserContextIsNotOwned, verifyGeolocation } from '../browserContext';
-import { CRConnection, ConnectionEvents, CRSession } from './crConnection';
-import { Page, PageEvent, PageBinding } from '../page';
-import { CRTarget } from './crTarget';
-import { Protocol } from './protocol';
-import { CRPage } from './crPage';
 import { Browser, createPageInNewContext } from '../browser';
+import { assertBrowserContextIsNotOwned, BrowserContext, BrowserContextBase, BrowserContextOptions, validateBrowserContextOptions, verifyGeolocation } from '../browserContext';
+import { Events as CommonEvents } from '../events';
+import { assert, debugError, helper } from '../helper';
 import * as network from '../network';
-import * as types from '../types';
+import { Page, PageBinding, PageEvent } from '../page';
 import * as platform from '../platform';
-import { readProtocolStream } from './crProtocolHelper';
 import { ConnectionTransport, SlowMoTransport } from '../transport';
-import { TimeoutSettings } from '../timeoutSettings';
+import * as types from '../types';
+import { ConnectionEvents, CRConnection, CRSession } from './crConnection';
+import { CRPage } from './crPage';
+import { readProtocolStream } from './crProtocolHelper';
+import { CRTarget } from './crTarget';
+import { Events } from './events';
+import { Protocol } from './protocol';
 
 export class CRBrowser extends platform.EventEmitter implements Browser {
   _connection: CRConnection;
@@ -226,21 +225,16 @@ export class CRBrowser extends platform.EventEmitter implements Browser {
   }
 }
 
-export class CRBrowserContext extends platform.EventEmitter implements BrowserContext {
+export class CRBrowserContext extends BrowserContextBase {
   readonly _browser: CRBrowser;
   readonly _browserContextId: string | null;
-  readonly _options: BrowserContextOptions;
-  readonly _timeoutSettings: TimeoutSettings;
   readonly _evaluateOnNewDocumentSources: string[];
-  readonly _pageBindings = new Map<string, PageBinding>();
   private _closed = false;
 
   constructor(browser: CRBrowser, browserContextId: string | null, options: BrowserContextOptions) {
-    super();
+    super(options);
     this._browser = browser;
     this._browserContextId = browserContextId;
-    this._timeoutSettings = new TimeoutSettings();
-    this._options = options;
     this._evaluateOnNewDocumentSources = [];
   }
 
@@ -262,14 +256,6 @@ export class CRBrowserContext extends platform.EventEmitter implements BrowserCo
     return pages;
   }
 
-  setDefaultNavigationTimeout(timeout: number) {
-    this._timeoutSettings.setDefaultNavigationTimeout(timeout);
-  }
-
-  setDefaultTimeout(timeout: number) {
-    this._timeoutSettings.setDefaultTimeout(timeout);
-  }
-
   async pages(): Promise<Page[]> {
     const targets = this._browser._allTargets().filter(target => target.context() === this && target.type() === 'page');
     const pages = await Promise.all(targets.map(target => target.pageOrError()));

src/chromium/crPage.ts

@@ -101,7 +101,7 @@ export class CRPage implements PageDelegate {
       this._client.send('Target.setAutoAttach', { autoAttach: true, waitForDebuggerOnStart: true, flatten: true }),
       this._client.send('Emulation.setFocusEmulationEnabled', { enabled: true }),
     ];
-    const options = this._page.context()._options;
+    const options = this._browserContext._options;
     if (options.bypassCSP)
       promises.push(this._client.send('Page.setBypassCSP', { enabled: true }));
     if (options.ignoreHTTPSErrors)
@@ -336,7 +336,7 @@ export class CRPage implements PageDelegate {
 
   async updateExtraHTTPHeaders(): Promise<void> {
     const headers = network.mergeHeaders([
-      this._page.context()._options.extraHTTPHeaders,
+      this._browserContext._options.extraHTTPHeaders,
       this._page._state.extraHTTPHeaders
     ]);
     await this._client.send('Network.setExtraHTTPHeaders', { headers });
@@ -348,7 +348,7 @@ export class CRPage implements PageDelegate {
   }
 
   async _updateViewport(updateTouch: boolean): Promise<void> {
-    let viewport = this._page.context()._options.viewport || { width: 0, height: 0 };
+    let viewport = this._browserContext._options.viewport || { width: 0, height: 0 };
     const viewportSize = this._page._state.viewportSize;
     if (viewportSize)
       viewport = { ...viewport, ...viewportSize };

src/dom.ts

@@ -160,7 +160,7 @@ export class ElementHandle<T extends Node = Node> extends js.JSHandle<T> {
     const frameId = await this._page._delegate.getOwnerFrame(this);
     if (!frameId)
       return null;
-    const pages = this._page.context()._existingPages();
+    const pages = this._page._browserContext._existingPages();
     for (const page of pages) {
       const frame = page._frameManager.frame(frameId);
       if (frame)

src/firefox/ffBrowser.ts

@@ -16,19 +16,18 @@
  */
 
 import { Browser, createPageInNewContext } from '../browser';
-import { BrowserContext, BrowserContextOptions, validateBrowserContextOptions, assertBrowserContextIsNotOwned } from '../browserContext';
+import { assertBrowserContextIsNotOwned, BrowserContext, BrowserContextBase, BrowserContextOptions, validateBrowserContextOptions } from '../browserContext';
 import { Events } from '../events';
 import { assert, helper, RegisteredListener } from '../helper';
 import * as network from '../network';
-import * as types from '../types';
-import { Page, PageEvent, PageBinding } from '../page';
-import { ConnectionEvents, FFConnection, FFSessionEvents, FFSession } from './ffConnection';
-import { FFPage } from './ffPage';
+import { Page, PageBinding, PageEvent } from '../page';
 import * as platform from '../platform';
-import { Protocol } from './protocol';
 import { ConnectionTransport, SlowMoTransport } from '../transport';
-import { TimeoutSettings } from '../timeoutSettings';
+import * as types from '../types';
+import { ConnectionEvents, FFConnection, FFSession, FFSessionEvents } from './ffConnection';
 import { headersArray } from './ffNetworkManager';
+import { FFPage } from './ffPage';
+import { Protocol } from './protocol';
 
 export class FFBrowser extends platform.EventEmitter implements Browser {
   _connection: FFConnection;
@@ -269,21 +268,16 @@ class Target {
   }
 }
 
-export class FFBrowserContext extends platform.EventEmitter implements BrowserContext {
+export class FFBrowserContext extends BrowserContextBase {
   readonly _browser: FFBrowser;
   readonly _browserContextId: string | null;
-  readonly _options: BrowserContextOptions;
-  readonly _timeoutSettings: TimeoutSettings;
   private _closed = false;
   private readonly _evaluateOnNewDocumentSources: string[];
-  readonly _pageBindings = new Map<string, PageBinding>();
 
   constructor(browser: FFBrowser, browserContextId: string | null, options: BrowserContextOptions) {
-    super();
+    super(options);
     this._browser = browser;
     this._browserContextId = browserContextId;
-    this._timeoutSettings = new TimeoutSettings();
-    this._options = options;
     this._evaluateOnNewDocumentSources = [];
   }
 

src/firefox/ffPage.ts

@@ -26,7 +26,7 @@ import { Events } from '../events';
 import * as dialog from '../dialog';
 import { Protocol } from './protocol';
 import { RawMouseImpl, RawKeyboardImpl } from './ffInput';
-import { BrowserContext } from '../browserContext';
+import { BrowserContextBase } from '../browserContext';
 import { getAccessibilityTree } from './ffAccessibility';
 import * as types from '../types';
 import * as platform from '../platform';
@@ -45,7 +45,7 @@ export class FFPage implements PageDelegate {
   private _eventListeners: RegisteredListener[];
   private _workers = new Map<string, { frameId: string, session: FFSession }>();
 
-  constructor(session: FFSession, browserContext: BrowserContext, openerResolver: () => Promise<Page | null>) {
+  constructor(session: FFSession, browserContext: BrowserContextBase, openerResolver: () => Promise<Page | null>) {
     this._session = session;
     this._openerResolver = openerResolver;
     this.rawKeyboard = new RawKeyboardImpl(session);

src/page.ts

@@ -25,7 +25,7 @@ import { Screenshotter } from './screenshotter';
 import { TimeoutSettings } from './timeoutSettings';
 import * as types from './types';
 import { Events } from './events';
-import { BrowserContext } from './browserContext';
+import { BrowserContext, BrowserContextBase } from './browserContext';
 import { ConsoleMessage, ConsoleMessageLocation } from './console';
 import * as accessibility from './accessibility';
 import * as platform from './platform';
@@ -113,7 +113,7 @@ export class Page extends platform.EventEmitter {
   private _disconnected = false;
   private _disconnectedCallback: (e: Error) => void;
   readonly _disconnectedPromise: Promise<Error>;
-  private _browserContext: BrowserContext;
+  readonly _browserContext: BrowserContextBase;
   readonly keyboard: input.Keyboard;
   readonly mouse: input.Mouse;
   readonly _timeoutSettings: TimeoutSettings;
@@ -129,7 +129,7 @@ export class Page extends platform.EventEmitter {
   readonly _requestHandlers: { url: types.URLMatch, handler: (request: network.Request) => void }[] = [];
   _ownedContext: BrowserContext | undefined;
 
-  constructor(delegate: PageDelegate, browserContext: BrowserContext) {
+  constructor(delegate: PageDelegate, browserContext: BrowserContextBase) {
     super();
     this._delegate = delegate;
     this._closedCallback = () => {};
@@ -580,7 +580,7 @@ export class PageBinding {
     try {
       let binding = page._pageBindings.get(name);
       if (!binding)
-        binding = page.context()._pageBindings.get(name);
+        binding = page._browserContext._pageBindings.get(name);
       const result = await binding!.playwrightFunction(...args);
       expression = helper.evaluationString(deliverResult, name, seq, result);
     } catch (error) {