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How to use emulateNetworkConditions method in Puppeteer

Best JavaScript code snippet using puppeteer

browser_emulateNetworkConditions.js

Source:browser_emulateNetworkConditions.js

...19add_networking_task(async function offlineWithoutArguments({ client }) {20  const { Network } = client;21  let errorThrown = "";22  try {23    await Network.emulateNetworkConditions();24  } catch (e) {25    errorThrown = e.message;26  }27  ok(28    errorThrown.match(/offline: boolean value expected/),29    "Fails without any arguments"30  );31});32add_networking_task(async function offlineWithEmptyArguments({ client }) {33  const { Network } = client;34  let errorThrown = "";35  try {36    await Network.emulateNetworkConditions({});37  } catch (e) {38    errorThrown = e.message;39  }40  ok(41    errorThrown.match(/offline: boolean value expected/),42    "Fails with only empty arguments"43  );44});45add_networking_task(async function offlineWithInvalidArguments({ client }) {46  const { Network } = client;47  const testTable = [null, undefined, 1, "foo", [], {}];48  for (const testCase of testTable) {49    let errorThrown = "";50    try {51      await Network.emulateNetworkConditions({ offline: testCase });52    } catch (e) {53      errorThrown = e.message;54    }55    const testType = typeof testCase;56    ok(57      errorThrown.match(/offline: boolean value expected/),58      `Fails with ${testType}-type argument for offline`59    );60  }61});62add_networking_task(async function offlineWithUnsupportedArguments({ client }) {63  const { Network } = client;64  // Random valid values for the Network.emulateNetworkConditions command, even though we don't support them yet65  const args = {66    offline: true,67    latency: 500,68    downloadThroughput: 500,69    uploadThroughput: 500,70    connectionType: "cellular2g",71    someFutureArg: false,72  };73  await Network.emulateNetworkConditions(args);74  ok(true, "No errors should be thrown due to non-implemented arguments");75});76add_networking_task(async function emulateOfflineWhileOnline({ client }) {77  const { Network } = client;78  // Assert we're online to begin with79  await assertOfflineStatus(false);80  // Assert for offline81  await Network.emulateNetworkConditions({ offline: true });82  await assertOfflineStatus(true);83  // Assert we really can't navigate after setting offline84  await assertOfflineNavigationFails();85});86add_networking_task(async function emulateOfflineWhileOffline({ client }) {87  const { Network } = client;88  // Assert we're online to begin with89  await assertOfflineStatus(false);90  // Assert for offline91  await Network.emulateNetworkConditions({ offline: true });92  await assertOfflineStatus(true);93  // Assert for no-offline event, because we're offline - and changing to offline - so nothing changes94  await Network.emulateNetworkConditions({ offline: true });95  await assertOfflineStatus(true);96  // Assert we still can't navigate after setting offline twice97  await assertOfflineNavigationFails();98});99add_networking_task(async function emulateOnlineWhileOnline({ client }) {100  const { Network } = client;101  // Assert we're online to begin with102  await assertOfflineStatus(false);103  // Assert for no-offline event, because we're online - and changing to online - so nothing changes104  await Network.emulateNetworkConditions({ offline: false });105  await assertOfflineStatus(false);106});107add_networking_task(async function emulateOnlineWhileOffline({ client }) {108  const { Network } = client;109  // Assert we're online to begin with110  await assertOfflineStatus(false);111  // Assert for offline event, because we're online - and changing to offline112  const offlineChanged = Promise.race([113    BrowserTestUtils.waitForContentEvent(114      gBrowser.selectedBrowser,115      "online",116      true117    ),118    BrowserTestUtils.waitForContentEvent(119      gBrowser.selectedBrowser,120      "offline",121      true122    ),123  ]);124  await Network.emulateNetworkConditions({ offline: true });125  info("Waiting for offline event on window");126  is(await offlineChanged, "offline", "Only the offline-event should fire");127  await assertOfflineStatus(true);128  // Assert for online event, because we're offline - and changing to online129  const offlineChangedBack = Promise.race([130    BrowserTestUtils.waitForContentEvent(131      gBrowser.selectedBrowser,132      "online",133      true134    ),135    BrowserTestUtils.waitForContentEvent(136      gBrowser.selectedBrowser,137      "offline",138      true139    ),140  ]);141  await Network.emulateNetworkConditions({ offline: false });142  info("Waiting for online event on window");143  is(await offlineChangedBack, "online", "Only the online-event should fire");144  await assertOfflineStatus(false);145});146/**147 * Navigates to a page, and asserting any status code to appear148 */149async function assertOfflineNavigationFails() {150  // Tests always connect to localhost, and per bug 87717, localhost is now151  // reachable in offline mode.  To avoid this, disable any proxy.152  const proxyPrefValue = SpecialPowers.getIntPref("network.proxy.type");153  const diskPrefValue = SpecialPowers.getBoolPref("browser.cache.disk.enable");154  const memoryPrefValue = SpecialPowers.getBoolPref(155    "browser.cache.memory.enable"...

emulation.js

Source:emulation.js

1/**2 * @license3 * Copyright 2016 Google Inc. All Rights Reserved.4 *5 * Licensed under the Apache License, Version 2.0 (the "License");6 * you may not use this file except in compliance with the License.7 * You may obtain a copy of the License at8 *9 *      http://www.apache.org/licenses/LICENSE-2.010 *11 * Unless required by applicable law or agreed to in writing, software12 * distributed under the License is distributed on an "AS IS" BASIS,13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.14 * See the License for the specific language governing permissions and15 * limitations under the License.16 */17'use strict';18/**19 * Nexus 5X metrics adapted from emulated_devices/module.json20 */21const NEXUS5X_EMULATION_METRICS = {22  mobile: true,23  screenWidth: 412,24  screenHeight: 732,25  width: 412,26  height: 732,27  positionX: 0,28  positionY: 0,29  scale: 1,30  deviceScaleFactor: 2.625,31  fitWindow: false,32  screenOrientation: {33    angle: 0,34    type: 'portraitPrimary'35  }36};37const NEXUS5X_USERAGENT = {38  userAgent: 'Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5 Build/MRA58N) AppleWebKit/537.36' +39    '(KHTML, like Gecko) Chrome/52.0.2743.8 Mobile Safari/537.36'40};41const TYPICAL_MOBILE_THROTTLING_METRICS = {42  latency: 150, // 150ms43  downloadThroughput: Math.floor(1.6 * 1024 * 1024 / 8), // 1.6Mbps44  uploadThroughput: Math.floor(750 * 1024 / 8), // 750Kbps45  offline: false46};47const OFFLINE_METRICS = {48  offline: true,49  // values of 0 remove any active throttling. crbug.com/456324#c950  latency: 0,51  downloadThroughput: 0,52  uploadThroughput: 053};54const NO_THROTTLING_METRICS = {55  latency: 0,56  downloadThroughput: 0,57  uploadThroughput: 0,58  offline: false59};60const NO_CPU_THROTTLE_METRICS = {61  rate: 162};63const CPU_THROTTLE_METRICS = {64  rate: 565};66function enableNexus5X(driver) {67  /**68   * Finalizes touch emulation by enabling `"ontouchstart" in window` feature detect69   * to work. Messy hack, though copied verbatim from DevTools' emulation/TouchModel.js70   * where it's been working for years. addScriptToEvaluateOnLoad runs before any of the71   * page's JavaScript executes.72   */73  /* eslint-disable no-proto */ /* global window, document */ /* istanbul ignore next */74  const injectedTouchEventsFunction = function() {75    const touchEvents = ['ontouchstart', 'ontouchend', 'ontouchmove', 'ontouchcancel'];76    var recepients = [window.__proto__, document.__proto__];77    for (var i = 0; i < touchEvents.length; ++i) {78      for (var j = 0; j < recepients.length; ++j) {79        if (!(touchEvents[i] in recepients[j])) {80          Object.defineProperty(recepients[j], touchEvents[i], {81            value: null, writable: true, configurable: true, enumerable: true82          });83        }84      }85    }86  };87  /* eslint-enable */88  return Promise.all([89    driver.sendCommand('Emulation.setDeviceMetricsOverride', NEXUS5X_EMULATION_METRICS),90    // Network.enable must be called for UA overriding to work91    driver.sendCommand('Network.enable'),92    driver.sendCommand('Network.setUserAgentOverride', NEXUS5X_USERAGENT),93    driver.sendCommand('Emulation.setTouchEmulationEnabled', {94      enabled: true,95      configuration: 'mobile'96    }),97    driver.sendCommand('Page.addScriptToEvaluateOnLoad', {98      scriptSource: '(' + injectedTouchEventsFunction.toString() + ')()'99    })100  ]);101}102function enableNetworkThrottling(driver) {103  return driver.sendCommand('Network.emulateNetworkConditions', TYPICAL_MOBILE_THROTTLING_METRICS);104}105function disableNetworkThrottling(driver) {106  return driver.sendCommand('Network.emulateNetworkConditions', NO_THROTTLING_METRICS);107}108function goOffline(driver) {109  return driver.sendCommand('Network.emulateNetworkConditions', OFFLINE_METRICS);110}111function enableCPUThrottling(driver) {112  return driver.sendCommand('Emulation.setCPUThrottlingRate', CPU_THROTTLE_METRICS);113}114function disableCPUThrottling(driver) {115  return driver.sendCommand('Emulation.setCPUThrottlingRate', NO_CPU_THROTTLE_METRICS);116}117module.exports = {118  enableNexus5X,119  enableNetworkThrottling,120  disableNetworkThrottling,121  enableCPUThrottling,122  disableCPUThrottling,123  goOffline...

networkHandler.test.js

Source:networkHandler.test.js

1const chai = require('chai');2const rewire = require('rewire');3const expect = chai.expect;4const chaiAsPromissed = require('chai-as-promised');5chai.use(chaiAsPromissed);6const test_name = 'Network Handler';7describe(test_name, () => {8  let actualNetworkCondition, networkHandler;9  before(() => {10    networkHandler = rewire('../../../lib/handlers/networkHandler');11    delete process.env.TAIKO_EMULATE_NETWORK;12    let network = {13      requestWillBeSent: () => {},14      loadingFinished: () => {},15      loadingFailed: () => {},16      responseReceived: () => {},17      setCacheDisabled: () => {},18      setRequestInterception: () => {},19      requestIntercepted: () => {},20      emulateNetworkConditions: (networkCondition) => {21        actualNetworkCondition = networkCondition;22        return Promise.resolve();23      },24    };25    networkHandler.__set__('network', network);26  });27  after(() => {28    actualNetworkCondition = {};29    const createdSessionListener = networkHandler.__get__('createdSessionListener');30    networkHandler.__get__('eventHandler').removeListener('createdSession', createdSessionListener);31    networkHandler = rewire('../../../lib/handlers/networkHandler');32    networkHandler.__get__('eventHandler').removeListener('createdSession', createdSessionListener);33    process.env.TAIKO_EMULATE_NETWORK = '';34  });35  describe('setNetworkEmulation', () => {36    it('should invoke emulateNetworkConditions with a correct String option', async () => {37      const expectedNetworkCondition = {38        offline: false,39        downloadThroughput: 6400,40        uploadThroughput: 2560,41        latency: 500,42      };43      await networkHandler.setNetworkEmulation('GPRS');44      expect(actualNetworkCondition).to.deep.equal(expectedNetworkCondition);45    });46    it('should invoke emulateNetworkConditions with a correct Object option', async () => {47      const expectedNetworkCondition = {48        offline: false,49        downloadThroughput: 6400,50        uploadThroughput: 2560,51        latency: 500,52      };53      await networkHandler.setNetworkEmulation(expectedNetworkCondition);54      expect(actualNetworkCondition).to.deep.equal(expectedNetworkCondition);55    });56    it('should invoke emulateNetworkConditions with the set defaults if an incomplete Object option is provided', async () => {57      const defaultNetworkCondition = {58        offline: false,59        downloadThroughput: 0,60        uploadThroughput: 0,61        latency: 0,62      };63      const expectedNetworkCondition = {64        ...defaultNetworkCondition,65        uploadThroughput: 2500,66      };67      await networkHandler.setNetworkEmulation({ uploadThroughput: 2500 });68      expect(actualNetworkCondition).to.deep.equal(expectedNetworkCondition);69    });70    it('should throw error for invalid network type', async () => {71      return expect(72        networkHandler.setNetworkEmulation('invalid network'),73      ).to.eventually.rejectedWith(74        `Please set one of the given network types \n${[75          'GPRS',76          'Regular2G',77          'Good2G',78          'Regular3G',79          'Good3G',80          'Regular4G',81          'DSL',82          'WiFi',83          'Offline',84        ].join('\n')}`,85      );86    });87    it('should use networkType from config when not provided', async () => {88      process.env.TAIKO_EMULATE_NETWORK = 'GPRS';89      const expectedNetworkCondition = {90        offline: false,91        downloadThroughput: 6400,92        uploadThroughput: 2560,93        latency: 500,94      };95      await networkHandler.setNetworkEmulation();96      expect(actualNetworkCondition).to.deep.equal(expectedNetworkCondition);97    });98  });...

watcher.js

Source:watcher.js

1const puppeteer = require('puppeteer');2const fs = require('fs');3const { random, sample } = require('lodash');4const server = require('./server');5const { NETWORK_PRESETS, PORT } = require('./config')6const players = fs.readdirSync('./dist').filter((file) => file.match(/player-/));7const randomPlayer = sample(players);8console.log('Players found: ', players);9console.log('Random player chosen: ', randomPlayer);10(async () => {11  await server.start(PORT);12  const browser = await puppeteer.launch({executablePath: '/usr/bin/google-chrome', args: ['--no-sandbox', "--disable-dev-shm-usage"]});13  const page = await browser.newPage();14  const client = await page.target().createCDPSession()15  const randomStart = random(0, 100);16  if (randomStart < 15) {17    console.log('This bot got the short end of the stick...giving it a 3G connection.');18    await client.send('Network.emulateNetworkConditions', NETWORK_PRESETS['Regular3G']);19  } else if (randomStart > 75) {20    console.log('This bot wins! No throttling.');21  } else {22    const presetName = sample(Object.keys(NETWORK_PRESETS));23    console.log(`Assigning a random preset: ${presetName}`);24    await client.send('Network.emulateNetworkConditions', NETWORK_PRESETS[presetName]);25  }26  page.on('console', msg => {27    switch (msg._text) {28      case '--network_change--': {29        console.log('Network change triggered');30        client.send('Network.emulateNetworkConditions', sample(NETWORK_PRESETS));31        break;32      }33      case '--finished--': {34        console.log('Player example said farewell. Shutting things down.');35        browser.close();36        server.stop();37        break;38      }39    }40  });41  await page.goto(`http://localhost:${PORT}/${randomPlayer}`);...

offline.js

Source:offline.js

1// use window.navigator.onLine property to determine2// if the browser is offline or online3// https://caniuse.com/online-status4Cypress.assertOnline = () => {5    return cy.wrap(window).its('navigator.onLine').should('be.true')6}7Cypress.assertOffline = () => {8    return cy.wrap(window).its('navigator.onLine').should('be.false')9}10  11Cypress.goOffline = (fn) => {12    cy.log('**go offline**')13    .then(() => {14      Cypress.automation('remote:debugger:protocol',15        {16          command: 'Network.enable',17        })18    })19    .then(() => {20      Cypress.automation('remote:debugger:protocol',21        {22          command: 'Network.emulateNetworkConditions',23          params: {24            offline: true,25            latency: -1,26            downloadThroughput: -1,27            uploadThroughput: -1,28          },29        })30    })    31  }32  33Cypress.goOnline = (fn) => {34  cy.log('**go online**')35  .then(() => {36    // Remove all service workers37    Cypress.removeSWs()38    39    // https://chromedevtools.github.io/devtools-protocol/1-3/Network/#method-emulateNetworkConditions40    Cypress.automation('remote:debugger:protocol',41      {42        command: 'Network.emulateNetworkConditions',43        params: {44          offline: false,45          latency: -1,46          downloadThroughput: -1,47          uploadThroughput: -1,48        },49      }).then(() => {50        return Cypress.automation('remote:debugger:protocol',51          {52            command: 'Network.enable',53          })54      })55  })56}57  Cypress.removeSWs = () => {58    navigator.serviceWorker.getRegistrations().then(function(registrations) {59      for(let registration of registrations) {60      registration.unregister()61    } })...

utils.js

Source:utils.js

1export const EXTENDED_TIMEOUT = { timeout: 15000 }2export const goOffline = () => {3    cy.log('**go offline**')4        .then(() => {5            return Cypress.automation('remote:debugger:protocol', {6                command: 'Network.enable',7            })8        })9        .then(() => {10            return Cypress.automation('remote:debugger:protocol', {11                command: 'Network.emulateNetworkConditions',12                params: {13                    offline: true,14                    latency: -1,15                    downloadThroughput: -1,16                    uploadThroughput: -1,17                },18            })19        })20}21export const goOnline = () => {22    // disable offline mode, otherwise we will break our tests :)23    cy.log('**go online**')24        .then(() => {25            return Cypress.automation('remote:debugger:protocol', {26                command: 'Network.emulateNetworkConditions',27                params: {28                    offline: false,29                    latency: -1,30                    downloadThroughput: -1,31                    uploadThroughput: -1,32                },33            })34        })35        .then(() => {36            return Cypress.automation('remote:debugger:protocol', {37                command: 'Network.disable',38            })39        })...

index.js

Source:index.js

...13        latency:            10,14        downloadThroughput: 100000,15        uploadThroughput:   10000016    };17    await cdp.Network.emulateNetworkConditions(networkConditions);18    setTimeout(() => {19        networkConditions.offline = false;20        cdp.Network.emulateNetworkConditions(networkConditions);21    }, 5000);22    const expectedClickCount = 10;23    for (let i = 0; i < expectedClickCount; i++)24        await t.click('button');25    const actualClickCount = await getClickCount();26    await t.expect(actualClickCount).eql(expectedClickCount);...

network.js

Source:network.js

1const goOffline = () => {2	cy.log( '**go offline**' )3		.then( () => {4			return Cypress.automation( 'remote:debugger:protocol',5				{6					command: 'Network.enable'7				} )8		} )9		.then( () => {10			return Cypress.automation( 'remote:debugger:protocol',11				{12					command: 'Network.emulateNetworkConditions',13					params: {14						offline: true,15						latency: -1,16						downloadThroughput: -1,17						uploadThroughput: -118					}19				} )20		} )21}22const goOnline = () => {23	// disable offline mode, otherwise we will break our tests :)24	cy.log( '**go online**' )25		.then( () => {26			// https://chromedevtools.github.io/devtools-protocol/1-3/Network/#method-emulateNetworkConditions27			return Cypress.automation( 'remote:debugger:protocol',28				{29					command: 'Network.emulateNetworkConditions',30					params: {31						offline: false,32						latency: -1,33						downloadThroughput: -1,34						uploadThroughput: -135					}36				} )37		} )38		.then( () => {39			return Cypress.automation( 'remote:debugger:protocol',40				{41					command: 'Network.disable'42				} )43		} )44}...

Using AI Code Generation

1const puppeteer = require('puppeteer');2(async () => {3    const browser = await puppeteer.launch({ headless: false });4    const page = await browser.newPage();5    await page.emulateNetworkConditions({6    });7    await browser.close();8})();

Using AI Code Generation

1const puppeteer = require('puppeteer');2(async () => {3  const browser = await puppeteer.launch({headless: false});4  const page = await browser.newPage();5  await page.emulateNetworkConditions({6  });7  await page.screenshot({path: 'test.png'});8  await browser.close();9})();10const puppeteer = require('puppeteer');11(async () => {12  const browser = await puppeteer.launch({headless: false});13  const page = await browser.newPage();14  await page.emulate({15    viewport: {16    },17  });18  await page.screenshot({path: 'test.png'});19  await browser.close();20})();21const puppeteer = require('puppeteer');22(async () => {23  const browser = await puppeteer.launch({headless: false});24  const page = await browser.newPage();25  await page.emulate({26    viewport: {27    },28  });29  await page.screenshot({path: 'test.png'});30  await browser.close();31})();32const puppeteer = require('puppeteer');33(async () => {34  const browser = await puppeteer.launch({headless: false});35  const page = await browser.newPage();

Using AI Code Generation

1const puppeteer = require('puppeteer');2(async () => {3    const browser = await puppeteer.launch();4    const page = await browser.newPage();5    await page.emulateNetworkConditions({6    });7    await browser.close();8})();

Using AI Code Generation

1const puppeteer = require('puppeteer');2(async () => {3  const browser = await puppeteer.launch();4  const page = await browser.newPage();5  await page.emulateNetworkConditions({6  });7  await page.screenshot({path: 'example.png'});8  await browser.close();9})();

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