fix(colorScheme): make light scheme default on all browsers (#1668)

docs/api.md

@@ -215,6 +215,7 @@ Indicates that the browser is connected.
   - `httpCredentials` <[Object]> Credentials for [HTTP authentication](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication).
     - `username` <[string]>
     - `password` <[string]>
+  - `colorScheme` <"dark"|"light"|"no-preference"> Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See [page.emulateMedia(options)](#pageemulatemediaoptions) for more details. Defaults to '`light`'.
 - returns: <[Promise]<[BrowserContext]>>
 
 Creates a new browser context. It won't share cookies/cache with other browser contexts.
@@ -255,6 +256,7 @@ Creates a new browser context. It won't share cookies/cache with other browser c
   - `httpCredentials` <[Object]> Credentials for [HTTP authentication](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication).
     - `username` <[string]>
     - `password` <[string]>
+  - `colorScheme` <"dark"|"light"|"no-preference"> Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See [page.emulateMedia(options)](#pageemulatemediaoptions) for more details. Defaults to '`light`'.
 - returns: <[Promise]<[Page]>>
 
 Creates a new page in a new browser context. Closing this page will close the context as well.

package.json

@@ -9,7 +9,7 @@
   "main": "index.js",
   "playwright": {
     "chromium_revision": "754895",
-    "firefox_revision": "1071",
+    "firefox_revision": "1072",
     "webkit_revision": "1188"
   },
   "scripts": {

src/browserContext.ts

@@ -40,6 +40,7 @@ export type BrowserContextOptions = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
+  colorScheme?: types.ColorScheme,
   acceptDownloads?: boolean
 };
 

src/chromium/crPage.ts

@@ -150,8 +150,8 @@ export class CRPage implements PageDelegate {
     await this._mainFrameSession._updateViewport();
   }
 
-  async setEmulateMedia(mediaType: types.MediaType | null, colorScheme: types.ColorScheme | null): Promise<void> {
+  async updateEmulateMedia(): Promise<void> {
-    await this._forAllFrameSessions(frame => frame._setEmulateMedia(mediaType, colorScheme));
+    await this._forAllFrameSessions(frame => frame._updateEmulateMedia());
   }
 
   async updateRequestInterception(): Promise<void> {
@@ -422,6 +422,7 @@ class FrameSession {
     promises.push(this._updateRequestInterception());
     promises.push(this._updateOffline());
     promises.push(this._updateHttpCredentials());
+    promises.push(this._updateEmulateMedia());
     for (const binding of this._crPage._browserContext._pageBindings.values())
       promises.push(this._initBinding(binding));
     for (const source of this._crPage._browserContext._evaluateOnNewDocumentSources)
@@ -687,9 +688,10 @@ class FrameSession {
     await Promise.all(promises);
   }
 
-  async _setEmulateMedia(mediaType: types.MediaType | null, colorScheme: types.ColorScheme | null): Promise<void> {
+  async _updateEmulateMedia(): Promise<void> {
+    const colorScheme = this._page._state.colorScheme || this._crPage._browserContext._options.colorScheme || 'light';
     const features = colorScheme ? [{ name: 'prefers-color-scheme', value: colorScheme }] : [];
-    await this._client.send('Emulation.setEmulatedMedia', { media: mediaType || '', features });
+    await this._client.send('Emulation.setEmulatedMedia', { media: this._page._state.mediaType || '', features });
   }
 
   async _updateRequestInterception(): Promise<void> {

src/firefox/ffBrowser.ts

@@ -164,6 +164,8 @@ export class FFBrowserContext extends BrowserContextBase {
       await this.setGeolocation(this._options.geolocation);
     if (this._options.offline)
       await this.setOffline(this._options.offline);
+    if (this._options.colorScheme)
+      await this._setColorScheme(this._options.colorScheme);
   }
 
   _ffPages(): FFPage[] {
@@ -259,6 +261,10 @@ export class FFBrowserContext extends BrowserContextBase {
     await this._browser._connection.send('Browser.setOnlineOverride', { browserContextId: this._browserContextId || undefined, override: offline ? 'offline' : 'online' });
   }
 
+  async _setColorScheme(colorScheme?: types.ColorScheme): Promise<void> {
+    await this._browser._connection.send('Browser.setColorScheme', { browserContextId: this._browserContextId || undefined, colorScheme });
+  }
+
   async setHTTPCredentials(httpCredentials: types.Credentials | null): Promise<void> {
     this._options.httpCredentials = httpCredentials || undefined;
     await this._browser._connection.send('Browser.setHTTPCredentials', { browserContextId: this._browserContextId || undefined, credentials: httpCredentials });

src/firefox/ffPage.ts

@@ -284,10 +284,11 @@ export class FFPage implements PageDelegate {
     });
   }
 
-  async setEmulateMedia(mediaType: types.MediaType | null, colorScheme: types.ColorScheme | null): Promise<void> {
+  async updateEmulateMedia(): Promise<void> {
+    const colorScheme = this._page._state.colorScheme || this._browserContext._options.colorScheme || 'light';
     await this._session.send('Page.setEmulatedMedia', {
-      type: mediaType === null ? undefined : mediaType,
+      type: this._page._state.mediaType === null ? undefined : this._page._state.mediaType,
-      colorScheme: colorScheme === null ? undefined : colorScheme
+      colorScheme
     });
   }
 

src/page.ts

@@ -48,7 +48,7 @@ export interface PageDelegate {
 
   updateExtraHTTPHeaders(): Promise<void>;
   setViewportSize(viewportSize: types.Size): Promise<void>;
-  setEmulateMedia(mediaType: types.MediaType | null, colorScheme: types.ColorScheme | null): Promise<void>;
+  updateEmulateMedia(): Promise<void>;
   updateRequestInterception(): Promise<void>;
   setFileChooserIntercepted(enabled: boolean): Promise<void>;
 
@@ -357,7 +357,7 @@ export class Page extends ExtendedEventEmitter {
       this._state.mediaType = options.media;
     if (options.colorScheme !== undefined)
       this._state.colorScheme = options.colorScheme;
-    await this._delegate.setEmulateMedia(this._state.mediaType, this._state.colorScheme);
+    await this._delegate.updateEmulateMedia();
   }
 
   async setViewportSize(viewportSize: types.Size) {

src/webkit/wkPage.ts

@@ -162,7 +162,7 @@ export class WKPage implements PageDelegate {
         height: this._page._state.viewportSize.height,
       }));
     }
-
+    promises.push(this.updateEmulateMedia());
     promises.push(session.send('Network.setExtraHTTPHeaders', { headers: this._calculateExtraHTTPHeaders() }));
     if (contextOptions.offline)
       promises.push(session.send('Network.setEmulateOfflineState', { offline: true }));
@@ -492,8 +492,9 @@ export class WKPage implements PageDelegate {
     return headers;
   }
 
-  async setEmulateMedia(mediaType: types.MediaType | null, colorScheme: types.ColorScheme | null): Promise<void> {
+  async updateEmulateMedia(): Promise<void> {
-    await this._forAllSessions(session => WKPage._setEmulateMedia(session, mediaType, colorScheme));
+    const colorScheme = this._page._state.colorScheme || this._browserContext._options.colorScheme || 'light';
+    await this._forAllSessions(session => WKPage._setEmulateMedia(session, this._page._state.mediaType, colorScheme));
   }
 
   async setViewportSize(viewportSize: types.Size): Promise<void> {

test/emulation.spec.js

@@ -15,6 +15,8 @@
  * limitations under the License.
  */
 
+const utils = require('./utils');
+
 /**
  * @type {PageTestSuite}
  */
@@ -236,6 +238,21 @@ module.exports.describe = function({testRunner, expect, playwright, headless, FF
         expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: no-preference)').matches)).toBe(true);
       }
     });
+    it('should default to light', async({page, server}) => {
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: light)').matches)).toBe(true);
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: dark)').matches)).toBe(false);
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: no-preference)').matches)).toBe(false);
+
+      await page.emulateMedia({ colorScheme: '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);
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: no-preference)').matches)).toBe(false);
+
+      await page.emulateMedia({ colorScheme: null });
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: dark)').matches)).toBe(false);
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: light)').matches)).toBe(true);
+      expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: no-preference)').matches)).toBe(false);
+    });
     it('should throw in case of bad argument', async({page, server}) => {
       let error = null;
       await page.emulateMedia({ colorScheme: 'bad' }).catch(e => error = e);
@@ -253,6 +270,39 @@ module.exports.describe = function({testRunner, expect, playwright, headless, FF
       await navigated;
       expect(await page.evaluate(() => matchMedia('(prefers-color-scheme: dark)').matches)).toBe(true);
     });
+    it('should work in popup', async({browser, server}) => {
+      {
+        const context = await browser.newContext({ colorScheme: 'dark' });
+        const page = await context.newPage();
+        await page.goto(server.EMPTY_PAGE);
+        const [popup] = await Promise.all([
+          page.waitForEvent('popup'),
+          page.evaluate(url => { window.open(url); }, server.EMPTY_PAGE),
+        ]);
+        expect(await popup.evaluate(() => matchMedia('(prefers-color-scheme: light)').matches)).toBe(false);
+        expect(await popup.evaluate(() => matchMedia('(prefers-color-scheme: dark)').matches)).toBe(true);
+        await context.close();
+      }
+      {
+        const page = await browser.newPage({ colorScheme: 'light' });
+        await page.goto(server.EMPTY_PAGE);
+        const [popup] = await Promise.all([
+          page.waitForEvent('popup'),
+          page.evaluate(url => { window.open(url); }, server.EMPTY_PAGE),
+        ]);
+        expect(await popup.evaluate(() => matchMedia('(prefers-color-scheme: light)').matches)).toBe(true);
+        expect(await popup.evaluate(() => matchMedia('(prefers-color-scheme: dark)').matches)).toBe(false);
+        await page.close();
+      }
+    });
+    it('should work in cross-process iframe', async({browser, server}) => {
+      const page = await browser.newPage({ colorScheme: 'dark' });
+      await page.goto(server.EMPTY_PAGE);
+      await utils.attachFrame(page, 'frame1', server.CROSS_PROCESS_PREFIX + '/empty.html');
+      const frame = page.frames()[1];
+      expect(await frame.evaluate(() => matchMedia('(prefers-color-scheme: dark)').matches)).toBe(true);
+      await page.close();
+    });
   });
 
   describe('BrowserContext({timezoneId})', function() {