feat: Allow passing custom chromium preferences (#1)

Author: aklinker1

package-lock.json

@@ -62,6 +62,7 @@
     "parse-json": "7.1.1",
     "pino": "9.6.0",
     "promise-toolbox": "0.21.0",
+    "set-value": "4.1.0",
     "source-map-support": "0.5.21",
     "strip-bom": "5.0.0",
     "strip-json-comments": "5.0.1",

package.json

@@ -50,6 +50,7 @@ export default async function run(
     firefoxApkComponent,
     // Chromium CLI options.
     chromiumBinary,
+    chromiumPref,
     chromiumProfile,
   },
   {
@@ -82,7 +83,12 @@ export default async function run(
 
   // Create an alias for --pref since it has been transformed into an
   // object containing one or more preferences.
-  const customPrefs = pref;
+  const customPrefs = { ...pref };
+
+  // Create an alias for --chromium-pref since it has been transformed into an
+  // object containing one or more preferences.
+  const customChromiumPrefs = { ...chromiumPref };
+
   const manifestData = await getValidatedManifest(sourceDir);
 
   const profileDir = firefoxProfile || chromiumProfile;
@@ -190,6 +196,7 @@ export default async function run(
       ...commonRunnerParams,
       chromiumBinary,
       chromiumProfile,
+      customChromiumPrefs,
     };
 
     const chromiumRunner = await createExtensionRunner({

src/cmd/run.js

@@ -11,6 +11,7 @@ import {
   launch as defaultChromiumLaunch,
 } from 'chrome-launcher';
 import WebSocket, { WebSocketServer } from 'ws';
+import set from 'set-value';
 
 import { createLogger } from '../util/logger.js';
 import { TempDir } from '../util/temp-dir.js';
@@ -29,6 +30,10 @@ export const DEFAULT_CHROME_FLAGS = ChromeLauncher.defaultFlags().filter(
   (flag) => !EXCLUDED_CHROME_FLAGS.includes(flag),
 );
 
+const DEFAULT_PREFS = {
+  'extensions.ui.developer_mode': true,
+};
+
 /**
  * Implements an IExtensionRunner which manages a Chromium instance.
  */
@@ -214,6 +219,7 @@ export class ChromiumExtensionRunner {
       userDataDir,
       // Ignore default flags to keep the extension enabled.
       ignoreDefaultFlags: true,
+      prefs: this.getPrefs(),
     });
 
     this.chromiumInstance.process.once('close', () => {
@@ -418,4 +424,18 @@ export class ChromiumExtensionRunner {
       }
     }
   }
+
+  /**
+   * Returns a deep preferences object based on a set of flat preferences, like
+   * "extensions.ui.developer_mode".
+   */
+  getPrefs() {
+    return Object.entries({
+      ...DEFAULT_PREFS,
+      ...(this.params.customChromiumPrefs || {}),
+    }).reduce((prefs, [key, value]) => {
+      set(prefs, key, value);
+      return prefs;
+    }, {});
+  }
 }

src/extension-runners/chromium.js

@@ -28,10 +28,7 @@ function prepareExtensionRunnerParams({ params } = {}) {
   };
   const runnerParams = {
     extensions: [
-      {
-        sourceDir: '/fake/sourceDir',
-        manifestData: deepcopy(basicManifest),
-      },
+      { sourceDir: '/fake/sourceDir', manifestData: deepcopy(basicManifest) },
     ],
     keepProfileChanges: false,
     startUrl: undefined,
@@ -47,7 +44,7 @@ function prepareExtensionRunnerParams({ params } = {}) {
 
 describe('util/extension-runners/chromium', async () => {
   it('uses the expected chrome flags', () => {
-    // Flags from chrome-launcher v0.14.0
+    // Flags from chrome-launcher v1.1.0
     const expectedFlags = [
       '--disable-features=Translate,OptimizationHints,MediaRouter,DialMediaRouteProvider,CalculateNativeWinOcclusion,InterestFeedContentSuggestions,CertificateTransparencyComponentUpdater,AutofillServerCommunication,PrivacySandboxSettings4',
       '--disable-component-extensions-with-background-pages',
@@ -372,9 +369,7 @@ describe('util/extension-runners/chromium', async () => {
   });
 
   it('does use a random user-data-dir', async () => {
-    const { params } = prepareExtensionRunnerParams({
-      params: {},
-    });
+    const { params } = prepareExtensionRunnerParams({ params: {} });
 
     const spy = sinon.spy(TempDir.prototype, 'path');
 
@@ -394,9 +389,7 @@ describe('util/extension-runners/chromium', async () => {
   it('does pass a user-data-dir flag to chrome', async () =>
     withTempDir(async (tmpDir) => {
       const { params } = prepareExtensionRunnerParams({
-        params: {
-          chromiumProfile: tmpDir.path(),
-        },
+        params: { chromiumProfile: tmpDir.path() },
       });
 
       const spy = sinon.spy(TempDir.prototype, 'path');
@@ -618,6 +611,44 @@ describe('util/extension-runners/chromium', async () => {
       }),
   );
 
+  it('does pass default prefs to chrome', async () => {
+    const { params } = prepareExtensionRunnerParams();
+
+    const runnerInstance = new ChromiumExtensionRunner(params);
+    await runnerInstance.run();
+
+    sinon.assert.calledOnce(params.chromiumLaunch);
+    sinon.assert.calledWithMatch(params.chromiumLaunch, {
+      prefs: { extensions: { ui: { developer_mode: true } } },
+    });
+
+    await runnerInstance.exit();
+  });
+
+  it('does pass custom prefs to chrome', async () => {
+    const { params } = prepareExtensionRunnerParams({
+      params: {
+        customChromiumPrefs: {
+          'download.default_directory': '/some/directory',
+          'extensions.ui.developer_mode': false,
+        },
+      },
+    });
+
+    const runnerInstance = new ChromiumExtensionRunner(params);
+    await runnerInstance.run();
+
+    sinon.assert.calledOnce(params.chromiumLaunch);
+    sinon.assert.calledWithMatch(params.chromiumLaunch, {
+      prefs: {
+        download: { default_directory: '/some/directory' },
+        extensions: { ui: { developer_mode: false } },
+      },
+    });
+
+    await runnerInstance.exit();
+  });
+
   describe('reloadAllExtensions', () => {
     let runnerInstance;
     let wsClient;