emulation.spec.ts

/**
 * Copyright 2018 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.
 */

import expect from 'expect';
import {
  getTestState,
  setupTestBrowserHooks,
  setupTestPageAndContextHooks,
  itFailsFirefox,
  describeFailsFirefox,
} from './mocha-utils'; // eslint-disable-line import/extensions

describe('Emulation', () => {
  setupTestBrowserHooks();
  setupTestPageAndContextHooks();
  let iPhone;
  let iPhoneLandscape;

  before(() => {
    const { puppeteer } = getTestState();
    iPhone = puppeteer.devices['iPhone 6'];
    iPhoneLandscape = puppeteer.devices['iPhone 6 landscape'];
  });

  describe('Page.viewport', function () {
    it('should get the proper viewport size', async () => {
      const { page } = getTestState();

      expect(page.viewport()).toEqual({ width: 800, height: 600 });
      await page.setViewport({ width: 123, height: 456 });
      expect(page.viewport()).toEqual({ width: 123, height: 456 });
    });
    it('should support mobile emulation', async () => {
      const { page, server } = getTestState();

      await page.goto(server.PREFIX + '/mobile.html');
      expect(await page.evaluate(() => window.innerWidth)).toBe(800);
      await page.setViewport(iPhone.viewport);
      expect(await page.evaluate(() => window.innerWidth)).toBe(375);
      await page.setViewport({ width: 400, height: 300 });
      expect(await page.evaluate(() => window.innerWidth)).toBe(400);
    });
    it('should support touch emulation', async () => {
      const { page, server } = getTestState();

      await page.goto(server.PREFIX + '/mobile.html');
      expect(await page.evaluate(() => 'ontouchstart' in window)).toBe(false);
      await page.setViewport(iPhone.viewport);
      expect(await page.evaluate(() => 'ontouchstart' in window)).toBe(true);
      expect(await page.evaluate(dispatchTouch)).toBe('Received touch');
      await page.setViewport({ width: 100, height: 100 });
      expect(await page.evaluate(() => 'ontouchstart' in window)).toBe(false);

      function dispatchTouch() {
        let fulfill;
        const promise = new Promise((x) => (fulfill = x));
        window.ontouchstart = () => {
          fulfill('Received touch');
        };
        window.dispatchEvent(new Event('touchstart'));

        fulfill('Did not receive touch');

        return promise;
      }
    });
    it('should be detectable by Modernizr', async () => {
      const { page, server } = getTestState();

      await page.goto(server.PREFIX + '/detect-touch.html');
      expect(await page.evaluate(() => document.body.textContent.trim())).toBe(
        'NO'
      );
      await page.setViewport(iPhone.viewport);
      await page.goto(server.PREFIX + '/detect-touch.html');
      expect(await page.evaluate(() => document.body.textContent.trim())).toBe(
        'YES'
      );
    });
    it('should detect touch when applying viewport with touches', async () => {
      const { page, server } = getTestState();

      await page.setViewport({ width: 800, height: 600, hasTouch: true });
      await page.addScriptTag({ url: server.PREFIX + '/modernizr.js' });
      expect(await page.evaluate(() => globalThis.Modernizr.touchevents)).toBe(
        true
      );
    });
    itFailsFirefox('should support landscape emulation', async () => {
      const { page, server } = getTestState();

      await page.goto(server.PREFIX + '/mobile.html');
      expect(await page.evaluate(() => screen.orientation.type)).toBe(
        'portrait-primary'
      );
      await page.setViewport(iPhoneLandscape.viewport);
      expect(await page.evaluate(() => screen.orientation.type)).toBe(
        'landscape-primary'
      );
      await page.setViewport({ width: 100, height: 100 });
      expect(await page.evaluate(() => screen.orientation.type)).toBe(
        'portrait-primary'
      );
    });
  });

  describe('Page.emulate', function () {
    it('should work', async () => {
      const { page, server } = getTestState();

      await page.goto(server.PREFIX + '/mobile.html');
      await page.emulate(iPhone);
      expect(await page.evaluate(() => window.innerWidth)).toBe(375);
      expect(await page.evaluate(() => navigator.userAgent)).toContain(
        'iPhone'
      );
    });
    itFailsFirefox('should support clicking', async () => {
      const { page, server } = getTestState();

      await page.emulate(iPhone);
      await page.goto(server.PREFIX + '/input/button.html');
      const button = await page.$('button');
      await page.evaluate(
        (button: HTMLElement) => (button.style.marginTop = '200px'),
        button
      );
      await button.click();
      expect(await page.evaluate(() => globalThis.result)).toBe('Clicked');
    });
  });

  describe('Page.emulateMediaType', function () {
    itFailsFirefox('should work', async () => {
      const { page } = getTestState();

      expect(await page.evaluate(() => matchMedia('screen').matches)).toBe(
        true
      );
      expect(await page.evaluate(() => matchMedia('print').matches)).toBe(
        false
      );
      await page.emulateMediaType('print');
      expect(await page.evaluate(() => matchMedia('screen').matches)).toBe(
        false
      );
      expect(await page.evaluate(() => matchMedia('print').matches)).toBe(true);
      await page.emulateMediaType(null);
      expect(await page.evaluate(() => matchMedia('screen').matches)).toBe(
        true
      );
      expect(await page.evaluate(() => matchMedia('print').matches)).toBe(
        false
      );
    });
    it('should throw in case of bad argument', async () => {
      const { page } = getTestState();

      let error = null;
      await page.emulateMediaType('bad').catch((error_) => (error = error_));
      expect(error.message).toBe('Unsupported media type: bad');
    });
  });

  describe('Page.emulateMediaFeatures', function () {
    itFailsFirefox('should work', async () => {
      const { page } = getTestState();

      await page.emulateMediaFeatures([
        { name: 'prefers-reduced-motion', value: 'reduce' },
      ]);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-reduced-motion: reduce)').matches
        )
      ).toBe(true);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-reduced-motion: no-preference)').matches
        )
      ).toBe(false);
      await page.emulateMediaFeatures([
        { name: 'prefers-color-scheme', value: 'light' },
      ]);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-color-scheme: light)').matches
        )
      ).toBe(true);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-color-scheme: dark)').matches
        )
      ).toBe(false);
      await page.emulateMediaFeatures([
        { name: 'prefers-color-scheme', value: 'dark' },
      ]);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-color-scheme: dark)').matches
        )
      ).toBe(true);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-color-scheme: light)').matches
        )
      ).toBe(false);
      await page.emulateMediaFeatures([
        { name: 'prefers-reduced-motion', value: 'reduce' },
        { name: 'prefers-color-scheme', value: 'light' },
      ]);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-reduced-motion: reduce)').matches
        )
      ).toBe(true);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-reduced-motion: no-preference)').matches
        )
      ).toBe(false);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-color-scheme: light)').matches
        )
      ).toBe(true);
      expect(
        await page.evaluate(
          () => matchMedia('(prefers-color-scheme: dark)').matches
        )
      ).toBe(false);
      await page.emulateMediaFeatures([{ name: 'color-gamut', value: 'srgb' }]);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: p3)').matches)
      ).toBe(false);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: srgb)').matches)
      ).toBe(true);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: rec2020)').matches)
      ).toBe(false);
      await page.emulateMediaFeatures([{ name: 'color-gamut', value: 'p3' }]);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: p3)').matches)
      ).toBe(true);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: srgb)').matches)
      ).toBe(true);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: rec2020)').matches)
      ).toBe(false);
      await page.emulateMediaFeatures([
        { name: 'color-gamut', value: 'rec2020' },
      ]);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: p3)').matches)
      ).toBe(true);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: srgb)').matches)
      ).toBe(true);
      expect(
        await page.evaluate(() => matchMedia('(color-gamut: rec2020)').matches)
      ).toBe(true);
    });
    it('should throw in case of bad argument', async () => {
      const { page } = getTestState();

      let error = null;
      await page
        .emulateMediaFeatures([{ name: 'bad', value: '' }])
        .catch((error_) => (error = error_));
      expect(error.message).toBe('Unsupported media feature: bad');
    });
  });

  describeFailsFirefox('Page.emulateTimezone', function () {
    it('should work', async () => {
      const { page } = getTestState();

      await page.evaluate(() => {
        globalThis.date = new Date(1479579154987);
      });
      await page.emulateTimezone('America/Jamaica');
      expect(await page.evaluate(() => globalThis.date.toString())).toBe(
        'Sat Nov 19 2016 13:12:34 GMT-0500 (Eastern Standard Time)'
      );

      await page.emulateTimezone('Pacific/Honolulu');
      expect(await page.evaluate(() => globalThis.date.toString())).toBe(
        'Sat Nov 19 2016 08:12:34 GMT-1000 (Hawaii-Aleutian Standard Time)'
      );

      await page.emulateTimezone('America/Buenos_Aires');
      expect(await page.evaluate(() => globalThis.date.toString())).toBe(
        'Sat Nov 19 2016 15:12:34 GMT-0300 (Argentina Standard Time)'
      );

      await page.emulateTimezone('Europe/Berlin');
      expect(await page.evaluate(() => globalThis.date.toString())).toBe(
        'Sat Nov 19 2016 19:12:34 GMT+0100 (Central European Standard Time)'
      );
    });

    it('should throw for invalid timezone IDs', async () => {
      const { page } = getTestState();

      let error = null;
      await page.emulateTimezone('Foo/Bar').catch((error_) => (error = error_));
      expect(error.message).toBe('Invalid timezone ID: Foo/Bar');
      await page.emulateTimezone('Baz/Qux').catch((error_) => (error = error_));
      expect(error.message).toBe('Invalid timezone ID: Baz/Qux');
    });
  });

  describeFailsFirefox('Page.emulateVisionDeficiency', function () {
    it('should work', async () => {
      const { page, server } = getTestState();

      await page.setViewport({ width: 500, height: 500 });
      await page.goto(server.PREFIX + '/grid.html');

      {
        await page.emulateVisionDeficiency('none');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('screenshot-sanity.png');
      }

      {
        await page.emulateVisionDeficiency('achromatopsia');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('vision-deficiency-achromatopsia.png');
      }

      {
        await page.emulateVisionDeficiency('blurredVision');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('vision-deficiency-blurredVision.png');
      }

      {
        await page.emulateVisionDeficiency('deuteranopia');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('vision-deficiency-deuteranopia.png');
      }

      {
        await page.emulateVisionDeficiency('protanopia');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('vision-deficiency-protanopia.png');
      }

      {
        await page.emulateVisionDeficiency('tritanopia');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('vision-deficiency-tritanopia.png');
      }

      {
        await page.emulateVisionDeficiency('none');
        const screenshot = await page.screenshot();
        expect(screenshot).toBeGolden('screenshot-sanity.png');
      }
    });

    it('should throw for invalid vision deficiencies', async () => {
      const { page } = getTestState();

      let error = null;
      await page
        // @ts-expect-error deliberately passign invalid deficiency
        .emulateVisionDeficiency('invalid')
        .catch((error_) => (error = error_));
      expect(error.message).toBe('Unsupported vision deficiency: invalid');
    });
  });

  describeFailsFirefox('Page.emulateNetworkConditions', function () {
    it('should change navigator.connection.effectiveType', async () => {
      const { page, puppeteer } = getTestState();

      const slow3G = puppeteer.networkConditions['Slow 3G'];
      const fast3G = puppeteer.networkConditions['Fast 3G'];

      expect(
        await page.evaluate('window.navigator.connection.effectiveType')
      ).toBe('4g');
      await page.emulateNetworkConditions(fast3G);
      expect(
        await page.evaluate('window.navigator.connection.effectiveType')
      ).toBe('3g');
      await page.emulateNetworkConditions(slow3G);
      expect(
        await page.evaluate('window.navigator.connection.effectiveType')
      ).toBe('2g');
      await page.emulateNetworkConditions(null);
    });
  });

  describeFailsFirefox('Page.emulateCPUThrottling', function () {
    it('should slow down execution', async () => {
      const { page } = getTestState();

      async function measure() {
        const start = new Date();
        await page.evaluate(() => {
          let i = 0;
          while (i < 1000) {
            i++;
          }
        });

        const end = new Date();
        return +end - +start;
      }

      const baseline = await measure();
      await page.emulateCPUThrottling(100);
      const throttledTime = await measure();
      await page.emulateCPUThrottling(null);
      const timeWithoutThrottle = await measure();

      // Throttling is not super precise. 20 has been chosen as very loose
      // threshold just to make sure that throttling has at least _some_ effect.
      expect(throttledTime / baseline).toBeGreaterThan(20);
      expect(timeWithoutThrottle / baseline).toBeLessThan(20);
    });
  });
});