puppeteer/lib/FrameManager.js
Andrey Lushnikov 0b94fa70eb
chore: stop using console.assert everywhere (#2646)
Since Node 10, `console.assert` no longer throws an AssertionError.
(This is generally good since it aligns Node.js with Browsers.)

This patch migrates all usages of `console.assert` in our codebase.
- All the `lib/` and testing code is migrated onto a handmade `assert`
function. This is to make Puppeteer transpilation / bundling easier.
- All the tooling is switched to use Node's `assert` module.

Fixes #2547.
2018-05-31 16:53:51 -07:00

996 lines
28 KiB
JavaScript

/**
* Copyright 2017 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
const fs = require('fs');
const EventEmitter = require('events');
const {helper, assert} = require('./helper');
const {ExecutionContext, JSHandle} = require('./ExecutionContext');
const ElementHandle = require('./ElementHandle');
const readFileAsync = helper.promisify(fs.readFile);
class FrameManager extends EventEmitter {
/**
* @param {!Puppeteer.CDPSession} client
* @param {!Protocol.Page.FrameTree} frameTree
* @param {!Puppeteer.Page} page
*/
constructor(client, frameTree, page) {
super();
this._client = client;
this._page = page;
/** @type {!Map<string, !Frame>} */
this._frames = new Map();
/** @type {!Map<number, !ExecutionContext>} */
this._contextIdToContext = new Map();
this._client.on('Page.frameAttached', event => this._onFrameAttached(event.frameId, event.parentFrameId));
this._client.on('Page.frameNavigated', event => this._onFrameNavigated(event.frame));
this._client.on('Page.navigatedWithinDocument', event => this._onFrameNavigatedWithinDocument(event.frameId, event.url));
this._client.on('Page.frameDetached', event => this._onFrameDetached(event.frameId));
this._client.on('Page.frameStoppedLoading', event => this._onFrameStoppedLoading(event.frameId));
this._client.on('Runtime.executionContextCreated', event => this._onExecutionContextCreated(event.context));
this._client.on('Runtime.executionContextDestroyed', event => this._onExecutionContextDestroyed(event.executionContextId));
this._client.on('Runtime.executionContextsCleared', event => this._onExecutionContextsCleared());
this._client.on('Page.lifecycleEvent', event => this._onLifecycleEvent(event));
this._handleFrameTree(frameTree);
}
/**
* @param {!Protocol.Page.lifecycleEventPayload} event
*/
_onLifecycleEvent(event) {
const frame = this._frames.get(event.frameId);
if (!frame)
return;
frame._onLifecycleEvent(event.loaderId, event.name);
this.emit(FrameManager.Events.LifecycleEvent, frame);
}
/**
* @param {string} frameId
*/
_onFrameStoppedLoading(frameId) {
const frame = this._frames.get(frameId);
if (!frame)
return;
frame._onLoadingStopped();
this.emit(FrameManager.Events.LifecycleEvent, frame);
}
/**
* @param {!Protocol.Page.FrameTree} frameTree
*/
_handleFrameTree(frameTree) {
if (frameTree.frame.parentId)
this._onFrameAttached(frameTree.frame.id, frameTree.frame.parentId);
this._onFrameNavigated(frameTree.frame);
if (!frameTree.childFrames)
return;
for (const child of frameTree.childFrames)
this._handleFrameTree(child);
}
/**
* @return {!Frame}
*/
mainFrame() {
return this._mainFrame;
}
/**
* @return {!Array<!Frame>}
*/
frames() {
return Array.from(this._frames.values());
}
/**
* @param {!string} frameId
* @return {?Frame}
*/
frame(frameId) {
return this._frames.get(frameId) || null;
}
/**
* @param {string} frameId
* @param {?string} parentFrameId
* @return {?Frame}
*/
_onFrameAttached(frameId, parentFrameId) {
if (this._frames.has(frameId))
return;
assert(parentFrameId);
const parentFrame = this._frames.get(parentFrameId);
const frame = new Frame(this._client, this._page, parentFrame, frameId);
this._frames.set(frame._id, frame);
this.emit(FrameManager.Events.FrameAttached, frame);
}
/**
* @param {!Protocol.Page.Frame} framePayload
*/
_onFrameNavigated(framePayload) {
const isMainFrame = !framePayload.parentId;
let frame = isMainFrame ? this._mainFrame : this._frames.get(framePayload.id);
assert(isMainFrame || frame, 'We either navigate top level or have old version of the navigated frame');
// Detach all child frames first.
if (frame) {
for (const child of frame.childFrames())
this._removeFramesRecursively(child);
}
// Update or create main frame.
if (isMainFrame) {
if (frame) {
// Update frame id to retain frame identity on cross-process navigation.
this._frames.delete(frame._id);
frame._id = framePayload.id;
} else {
// Initial main frame navigation.
frame = new Frame(this._client, this._page, null, framePayload.id);
}
this._frames.set(framePayload.id, frame);
this._mainFrame = frame;
}
// Update frame payload.
frame._navigated(framePayload);
this.emit(FrameManager.Events.FrameNavigated, frame);
}
/**
* @param {string} frameId
* @param {string} url
*/
_onFrameNavigatedWithinDocument(frameId, url) {
const frame = this._frames.get(frameId);
if (!frame)
return;
frame._navigatedWithinDocument(url);
this.emit(FrameManager.Events.FrameNavigatedWithinDocument, frame);
this.emit(FrameManager.Events.FrameNavigated, frame);
}
/**
* @param {string} frameId
*/
_onFrameDetached(frameId) {
const frame = this._frames.get(frameId);
if (frame)
this._removeFramesRecursively(frame);
}
_onExecutionContextCreated(contextPayload) {
const frameId = contextPayload.auxData && contextPayload.auxData.isDefault ? contextPayload.auxData.frameId : null;
const frame = frameId ? this._frames.get(frameId) : null;
const context = new ExecutionContext(this._client, contextPayload, this.createJSHandle.bind(this, contextPayload.id), frame);
this._contextIdToContext.set(contextPayload.id, context);
if (frame)
frame._setDefaultContext(context);
}
/**
* @param {!ExecutionContext} context
*/
_removeContext(context) {
if (context.frame())
context.frame()._setDefaultContext(null);
}
/**
* @param {number} executionContextId
*/
_onExecutionContextDestroyed(executionContextId) {
const context = this._contextIdToContext.get(executionContextId);
if (!context)
return;
this._contextIdToContext.delete(executionContextId);
this._removeContext(context);
}
_onExecutionContextsCleared() {
for (const context of this._contextIdToContext.values())
this._removeContext(context);
this._contextIdToContext.clear();
}
/**
* @param {number} contextId
* @param {!Protocol.Runtime.RemoteObject} remoteObject
* @return {!JSHandle}
*/
createJSHandle(contextId, remoteObject) {
const context = this._contextIdToContext.get(contextId);
assert(context, 'INTERNAL ERROR: missing context with id = ' + contextId);
if (remoteObject.subtype === 'node')
return new ElementHandle(context, this._client, remoteObject, this._page, this);
return new JSHandle(context, this._client, remoteObject);
}
/**
* @param {!Frame} frame
*/
_removeFramesRecursively(frame) {
for (const child of frame.childFrames())
this._removeFramesRecursively(child);
frame._detach();
this._frames.delete(frame._id);
this.emit(FrameManager.Events.FrameDetached, frame);
}
}
/** @enum {string} */
FrameManager.Events = {
FrameAttached: 'frameattached',
FrameNavigated: 'framenavigated',
FrameDetached: 'framedetached',
LifecycleEvent: 'lifecycleevent',
FrameNavigatedWithinDocument: 'framenavigatedwithindocument'
};
/**
* @unrestricted
*/
class Frame {
/**
* @param {!Puppeteer.CDPSession} client
* @param {?Frame} parentFrame
* @param {string} frameId
*/
constructor(client, page, parentFrame, frameId) {
this._client = client;
this._page = page;
this._parentFrame = parentFrame;
this._url = '';
this._id = frameId;
/** @type {?Promise<!ElementHandle>} */
this._documentPromise = null;
/** @type {?Promise<!ExecutionContext>} */
this._contextPromise = null;
this._contextResolveCallback = null;
this._setDefaultContext(null);
/** @type {!Set<!WaitTask>} */
this._waitTasks = new Set();
this._loaderId = '';
/** @type {!Set<string>} */
this._lifecycleEvents = new Set();
/** @type {!Set<!Frame>} */
this._childFrames = new Set();
if (this._parentFrame)
this._parentFrame._childFrames.add(this);
}
/**
* @param {?ExecutionContext} context
*/
_setDefaultContext(context) {
if (context) {
this._contextResolveCallback.call(null, context);
this._contextResolveCallback = null;
for (const waitTask of this._waitTasks)
waitTask.rerun();
} else {
this._documentPromise = null;
this._contextPromise = new Promise(fulfill => {
this._contextResolveCallback = fulfill;
});
}
}
/**
* @return {!Promise<!ExecutionContext>}
*/
executionContext() {
return this._contextPromise;
}
/**
* @param {function()|string} pageFunction
* @param {!Array<*>} args
* @return {!Promise<!Puppeteer.JSHandle>}
*/
async evaluateHandle(pageFunction, ...args) {
const context = await this._contextPromise;
return context.evaluateHandle(pageFunction, ...args);
}
/**
* @param {Function|string} pageFunction
* @param {!Array<*>} args
* @return {!Promise<*>}
*/
async evaluate(pageFunction, ...args) {
const context = await this._contextPromise;
return context.evaluate(pageFunction, ...args);
}
/**
* @param {string} selector
* @return {!Promise<?ElementHandle>}
*/
async $(selector) {
const document = await this._document();
const value = await document.$(selector);
return value;
}
/**
* @return {!Promise<!ElementHandle>}
*/
async _document() {
if (this._documentPromise)
return this._documentPromise;
this._documentPromise = this._contextPromise.then(async context => {
const document = await context.evaluateHandle('document');
return document.asElement();
});
return this._documentPromise;
}
/**
* @param {string} expression
* @return {!Promise<!Array<!ElementHandle>>}
*/
async $x(expression) {
const document = await this._document();
const value = await document.$x(expression);
return value;
}
/**
* @param {string} selector
* @param {Function|string} pageFunction
* @param {!Array<*>} args
* @return {!Promise<(!Object|undefined)>}
*/
async $eval(selector, pageFunction, ...args) {
const document = await this._document();
return document.$eval(selector, pageFunction, ...args);
}
/**
* @param {string} selector
* @param {Function|string} pageFunction
* @param {!Array<*>} args
* @return {!Promise<(!Object|undefined)>}
*/
async $$eval(selector, pageFunction, ...args) {
const document = await this._document();
const value = await document.$$eval(selector, pageFunction, ...args);
return value;
}
/**
* @param {string} selector
* @return {!Promise<!Array<!ElementHandle>>}
*/
async $$(selector) {
const document = await this._document();
const value = await document.$$(selector);
return value;
}
/**
* @return {!Promise<String>}
*/
async content() {
return await this.evaluate(() => {
let retVal = '';
if (document.doctype)
retVal = new XMLSerializer().serializeToString(document.doctype);
if (document.documentElement)
retVal += document.documentElement.outerHTML;
return retVal;
});
}
/**
* @param {string} html
*/
async setContent(html) {
await this.evaluate(html => {
document.open();
document.write(html);
document.close();
}, html);
}
/**
* @return {string}
*/
name() {
return this._name || '';
}
/**
* @return {string}
*/
url() {
return this._url;
}
/**
* @return {?Frame}
*/
parentFrame() {
return this._parentFrame;
}
/**
* @return {!Array.<!Frame>}
*/
childFrames() {
return Array.from(this._childFrames);
}
/**
* @return {boolean}
*/
isDetached() {
return this._detached;
}
/**
* @param {Object} options
* @return {!Promise<!ElementHandle>}
*/
async addScriptTag(options) {
if (typeof options.url === 'string') {
const url = options.url;
try {
const context = await this._contextPromise;
return (await context.evaluateHandle(addScriptUrl, url, options.type)).asElement();
} catch (error) {
throw new Error(`Loading script from ${url} failed`);
}
}
if (typeof options.path === 'string') {
let contents = await readFileAsync(options.path, 'utf8');
contents += '//# sourceURL=' + options.path.replace(/\n/g, '');
const context = await this._contextPromise;
return (await context.evaluateHandle(addScriptContent, contents, options.type)).asElement();
}
if (typeof options.content === 'string') {
const context = await this._contextPromise;
return (await context.evaluateHandle(addScriptContent, options.content, options.type)).asElement();
}
throw new Error('Provide an object with a `url`, `path` or `content` property');
/**
* @param {string} url
* @param {string} type
* @return {!Promise<!HTMLElement>}
*/
async function addScriptUrl(url, type) {
const script = document.createElement('script');
script.src = url;
if (type)
script.type = type;
const promise = new Promise((res, rej) => {
script.onload = res;
script.onerror = rej;
});
document.head.appendChild(script);
await promise;
return script;
}
/**
* @param {string} content
* @param {string} type
* @return {!HTMLElement}
*/
function addScriptContent(content, type = 'text/javascript') {
const script = document.createElement('script');
script.type = type;
script.text = content;
let error = null;
script.onerror = e => error = e;
document.head.appendChild(script);
if (error)
throw error;
return script;
}
}
/**
* @param {Object} options
* @return {!Promise<!ElementHandle>}
*/
async addStyleTag(options) {
if (typeof options.url === 'string') {
const url = options.url;
try {
const context = await this._contextPromise;
return (await context.evaluateHandle(addStyleUrl, url)).asElement();
} catch (error) {
throw new Error(`Loading style from ${url} failed`);
}
}
if (typeof options.path === 'string') {
let contents = await readFileAsync(options.path, 'utf8');
contents += '/*# sourceURL=' + options.path.replace(/\n/g, '') + '*/';
const context = await this._contextPromise;
return (await context.evaluateHandle(addStyleContent, contents)).asElement();
}
if (typeof options.content === 'string') {
const context = await this._contextPromise;
return (await context.evaluateHandle(addStyleContent, options.content)).asElement();
}
throw new Error('Provide an object with a `url`, `path` or `content` property');
/**
* @param {string} url
* @return {!Promise<!HTMLElement>}
*/
async function addStyleUrl(url) {
const link = document.createElement('link');
link.rel = 'stylesheet';
link.href = url;
const promise = new Promise((res, rej) => {
link.onload = res;
link.onerror = rej;
});
document.head.appendChild(link);
await promise;
return link;
}
/**
* @param {string} content
* @return {!Promise<!HTMLElement>}
*/
async function addStyleContent(content) {
const style = document.createElement('style');
style.type = 'text/css';
style.appendChild(document.createTextNode(content));
const promise = new Promise((res, rej) => {
style.onload = res;
style.onerror = rej;
});
document.head.appendChild(style);
await promise;
return style;
}
}
/**
* @param {string} selector
* @param {!Object=} options
*/
async click(selector, options = {}) {
const handle = await this.$(selector);
assert(handle, 'No node found for selector: ' + selector);
await handle.click(options);
await handle.dispose();
}
/**
* @param {string} selector
*/
async focus(selector) {
const handle = await this.$(selector);
assert(handle, 'No node found for selector: ' + selector);
await handle.focus();
await handle.dispose();
}
/**
* @param {string} selector
*/
async hover(selector) {
const handle = await this.$(selector);
assert(handle, 'No node found for selector: ' + selector);
await handle.hover();
await handle.dispose();
}
/**
* @param {string} selector
* @param {!Array<string>} values
* @return {!Promise<!Array<string>>}
*/
select(selector, ...values){
for (const value of values)
assert(helper.isString(value), 'Values must be strings. Found value "' + value + '" of type "' + (typeof value) + '"');
return this.$eval(selector, (element, values) => {
if (element.nodeName.toLowerCase() !== 'select')
throw new Error('Element is not a <select> element.');
const options = Array.from(element.options);
element.value = undefined;
for (const option of options) {
option.selected = values.includes(option.value);
if (option.selected && !element.multiple)
break;
}
element.dispatchEvent(new Event('input', { 'bubbles': true }));
element.dispatchEvent(new Event('change', { 'bubbles': true }));
return options.filter(option => option.selected).map(option => option.value);
}, values);
}
/**
* @param {string} selector
*/
async tap(selector) {
const handle = await this.$(selector);
assert(handle, 'No node found for selector: ' + selector);
await handle.tap();
await handle.dispose();
}
/**
* @param {string} selector
* @param {string} text
* @param {{delay: (number|undefined)}=} options
*/
async type(selector, text, options) {
const handle = await this.$(selector);
assert(handle, 'No node found for selector: ' + selector);
await handle.type(text, options);
await handle.dispose();
}
/**
* @param {(string|number|Function)} selectorOrFunctionOrTimeout
* @param {!Object=} options
* @param {!Array<*>} args
* @return {!Promise}
*/
waitFor(selectorOrFunctionOrTimeout, options = {}, ...args) {
const xPathPattern = '//';
if (helper.isString(selectorOrFunctionOrTimeout)) {
const string = /** @type {string} */ (selectorOrFunctionOrTimeout);
if (string.startsWith(xPathPattern))
return this.waitForXPath(string, options);
return this.waitForSelector(string, options);
}
if (helper.isNumber(selectorOrFunctionOrTimeout))
return new Promise(fulfill => setTimeout(fulfill, selectorOrFunctionOrTimeout));
if (typeof selectorOrFunctionOrTimeout === 'function')
return this.waitForFunction(selectorOrFunctionOrTimeout, options, ...args);
return Promise.reject(new Error('Unsupported target type: ' + (typeof selectorOrFunctionOrTimeout)));
}
/**
* @param {string} selector
* @param {!Object=} options
* @return {!Promise}
*/
waitForSelector(selector, options = {}) {
return this._waitForSelectorOrXPath(selector, false, options);
}
/**
* @param {string} xpath
* @param {!Object=} options
* @return {!Promise}
*/
waitForXPath(xpath, options = {}) {
return this._waitForSelectorOrXPath(xpath, true, options);
}
/**
* @param {Function|string} pageFunction
* @param {!Object=} options
* @return {!Promise}
*/
waitForFunction(pageFunction, options = {}, ...args) {
const timeout = helper.isNumber(options.timeout) ? options.timeout : 30000;
const polling = options.polling || 'raf';
return new WaitTask(this, pageFunction, 'function', polling, timeout, ...args).promise;
}
/**
* @return {!Promise<string>}
*/
async title() {
return this.evaluate(() => document.title);
}
/**
* @param {string} selectorOrXPath
* @param {boolean} isXPath
* @param {!Object=} options
* @return {!Promise}
*/
_waitForSelectorOrXPath(selectorOrXPath, isXPath, options = {}) {
const waitForVisible = !!options.visible;
const waitForHidden = !!options.hidden;
const polling = waitForVisible || waitForHidden ? 'raf' : 'mutation';
const timeout = helper.isNumber(options.timeout) ? options.timeout : 30000;
return new WaitTask(this, predicate, `${isXPath ? 'XPath' : 'selector'} "${selectorOrXPath}"`, polling, timeout, selectorOrXPath, isXPath, waitForVisible, waitForHidden).promise;
/**
* @param {string} selectorOrXPath
* @param {boolean} isXPath
* @param {boolean} waitForVisible
* @param {boolean} waitForHidden
* @return {?Node|boolean}
*/
function predicate(selectorOrXPath, isXPath, waitForVisible, waitForHidden) {
const node = isXPath
? document.evaluate(selectorOrXPath, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue
: document.querySelector(selectorOrXPath);
if (!node)
return waitForHidden;
if (!waitForVisible && !waitForHidden)
return node;
const element = /** @type {Element} */ (node.nodeType === Node.TEXT_NODE ? node.parentElement : node);
const style = window.getComputedStyle(element);
const isVisible = style && style.visibility !== 'hidden' && hasVisibleBoundingBox();
const success = (waitForVisible === isVisible || waitForHidden === !isVisible);
return success ? node : null;
/**
* @return {boolean}
*/
function hasVisibleBoundingBox() {
const rect = element.getBoundingClientRect();
return !!(rect.top || rect.bottom || rect.width || rect.height);
}
}
}
/**
* @param {!Protocol.Page.Frame} framePayload
*/
_navigated(framePayload) {
this._name = framePayload.name;
// TODO(lushnikov): remove this once requestInterception has loaderId exposed.
this._navigationURL = framePayload.url;
this._url = framePayload.url;
}
/**
* @param {string} url
*/
_navigatedWithinDocument(url) {
this._url = url;
}
/**
* @param {string} loaderId
* @param {string} name
*/
_onLifecycleEvent(loaderId, name) {
if (name === 'init') {
this._loaderId = loaderId;
this._lifecycleEvents.clear();
}
this._lifecycleEvents.add(name);
}
_onLoadingStopped() {
this._lifecycleEvents.add('DOMContentLoaded');
this._lifecycleEvents.add('load');
}
_detach() {
for (const waitTask of this._waitTasks)
waitTask.terminate(new Error('waitForFunction failed: frame got detached.'));
this._detached = true;
if (this._parentFrame)
this._parentFrame._childFrames.delete(this);
this._parentFrame = null;
}
}
helper.tracePublicAPI(Frame);
class WaitTask {
/**
* @param {!Frame} frame
* @param {Function|string} predicateBody
* @param {string|number} polling
* @param {number} timeout
* @param {!Array<*>} args
*/
constructor(frame, predicateBody, title, polling, timeout, ...args) {
if (helper.isString(polling))
assert(polling === 'raf' || polling === 'mutation', 'Unknown polling option: ' + polling);
else if (helper.isNumber(polling))
assert(polling > 0, 'Cannot poll with non-positive interval: ' + polling);
else
throw new Error('Unknown polling options: ' + polling);
this._frame = frame;
this._polling = polling;
this._timeout = timeout;
this._predicateBody = helper.isString(predicateBody) ? 'return ' + predicateBody : 'return (' + predicateBody + ')(...args)';
this._args = args;
this._runCount = 0;
frame._waitTasks.add(this);
this.promise = new Promise((resolve, reject) => {
this._resolve = resolve;
this._reject = reject;
});
// Since page navigation requires us to re-install the pageScript, we should track
// timeout on our end.
if (timeout)
this._timeoutTimer = setTimeout(() => this.terminate(new Error(`waiting for ${title} failed: timeout ${timeout}ms exceeded`)), timeout);
this.rerun();
}
/**
* @param {!Error} error
*/
terminate(error) {
this._terminated = true;
this._reject(error);
this._cleanup();
}
async rerun() {
const runCount = ++this._runCount;
/** @type {?JSHandle} */
let success = null;
let error = null;
try {
success = await (await this._frame.executionContext()).evaluateHandle(waitForPredicatePageFunction, this._predicateBody, this._polling, this._timeout, ...this._args);
} catch (e) {
error = e;
}
if (this._terminated || runCount !== this._runCount) {
if (success)
await success.dispose();
return;
}
// Ignore timeouts in pageScript - we track timeouts ourselves.
if (!error && await this._frame.evaluate(s => !s, success)) {
await success.dispose();
return;
}
// When the page is navigated, the promise is rejected.
// We will try again in the new execution context.
if (error && error.message.includes('Execution context was destroyed'))
return;
// We could have tried to evaluate in a context which was already
// destroyed.
if (error && error.message.includes('Cannot find context with specified id'))
return;
if (error)
this._reject(error);
else
this._resolve(success);
this._cleanup();
}
_cleanup() {
clearTimeout(this._timeoutTimer);
this._frame._waitTasks.delete(this);
this._runningTask = null;
}
}
/**
* @param {string} predicateBody
* @param {string} polling
* @param {number} timeout
* @return {!Promise<*>}
*/
async function waitForPredicatePageFunction(predicateBody, polling, timeout, ...args) {
const predicate = new Function('...args', predicateBody);
let timedOut = false;
if (timeout)
setTimeout(() => timedOut = true, timeout);
if (polling === 'raf')
return await pollRaf();
if (polling === 'mutation')
return await pollMutation();
if (typeof polling === 'number')
return await pollInterval(polling);
/**
* @return {!Promise<*>}
*/
function pollMutation() {
const success = predicate.apply(null, args);
if (success)
return Promise.resolve(success);
let fulfill;
const result = new Promise(x => fulfill = x);
const observer = new MutationObserver(mutations => {
if (timedOut) {
observer.disconnect();
fulfill();
}
const success = predicate.apply(null, args);
if (success) {
observer.disconnect();
fulfill(success);
}
});
observer.observe(document, {
childList: true,
subtree: true,
attributes: true
});
return result;
}
/**
* @return {!Promise<*>}
*/
function pollRaf() {
let fulfill;
const result = new Promise(x => fulfill = x);
onRaf();
return result;
function onRaf() {
if (timedOut) {
fulfill();
return;
}
const success = predicate.apply(null, args);
if (success)
fulfill(success);
else
requestAnimationFrame(onRaf);
}
}
/**
* @param {number} pollInterval
* @return {!Promise<*>}
*/
function pollInterval(pollInterval) {
let fulfill;
const result = new Promise(x => fulfill = x);
onTimeout();
return result;
function onTimeout() {
if (timedOut) {
fulfill();
return;
}
const success = predicate.apply(null, args);
if (success)
fulfill(success);
else
setTimeout(onTimeout, pollInterval);
}
}
}
module.exports = {FrameManager, Frame};