From 50fe71372181a3da0ae71c14e5c83505dde17245 Mon Sep 17 00:00:00 2001
From: "R. N. West" <98110034+rnwst@users.noreply.github.com>
Date: Thu, 13 Nov 2025 21:44:37 +0000
Subject: [PATCH] fix: Ensured `navigator.webdriver != true` in launched
 Chromium

The `--remote-debugging-pipe` flag causes `navigator.webdriver == true`
in the launched Chromium instance (provided there is no existing
Chromium instance). The `--disable-blink-features=AutomationControlled`
flag needs to be passed to prevent this and avoid breaking websites with
bot detection features.
---
 src/extension-runners/chromium.js             | 15 ++++++++
 .../test-extension-runners/test.chromium.js   | 36 +++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/src/extension-runners/chromium.js b/src/extension-runners/chromium.js
index 047c7874bc..a2f91d813c 100644
--- a/src/extension-runners/chromium.js
+++ b/src/extension-runners/chromium.js
@@ -256,6 +256,21 @@ export class ChromiumExtensionRunner {
       chromeFlags.push(...this.params.args);
     }
 
+    // `--remote-debugging-pipe` results in `navigator.webdriver == true` in
+    // the launched Chromium instance (unless a Chromium session exists
+    // already, in which case the existing session is used, which typically
+    // has `navigator.webdriver == false`). This breaks websites with bot
+    // detection features. The following flag prevents this.
+    // Only pass this flag if `--enable-blink-features=AutomationControlled`
+    // is not passed.
+    if (
+      !chromeFlags.some((flag) =>
+        /^--enable-blink-features=(.*,)?AutomationControlled(,|$)/.test(flag),
+      )
+    ) {
+      chromeFlags.push('--disable-blink-features=AutomationControlled');
+    }
+
     // eslint-disable-next-line prefer-const
     let { userDataDir, profileDirName } =
       await ChromiumExtensionRunner.getProfilePaths(
diff --git a/tests/unit/test-extension-runners/test.chromium.js b/tests/unit/test-extension-runners/test.chromium.js
index 084d62891e..c3a22a116f 100644
--- a/tests/unit/test-extension-runners/test.chromium.js
+++ b/tests/unit/test-extension-runners/test.chromium.js
@@ -117,6 +117,7 @@ describe('util/extension-runners/chromium', async () => {
         ...DEFAULT_CHROME_FLAGS,
         '--remote-debugging-pipe',
         '--enable-unsafe-extension-debugging',
+        '--disable-blink-features=AutomationControlled',
       ],
       startingUrl: undefined,
     });
@@ -227,6 +228,7 @@ describe('util/extension-runners/chromium', async () => {
         ...DEFAULT_CHROME_FLAGS,
         '--remote-debugging-pipe',
         '--enable-unsafe-extension-debugging',
+        '--disable-blink-features=AutomationControlled',
       ],
       startingUrl: undefined,
     });
@@ -250,6 +252,7 @@ describe('util/extension-runners/chromium', async () => {
         ...DEFAULT_CHROME_FLAGS,
         '--remote-debugging-pipe',
         '--enable-unsafe-extension-debugging',
+        '--disable-blink-features=AutomationControlled',
         'url2',
         'url3',
       ],
@@ -281,6 +284,7 @@ describe('util/extension-runners/chromium', async () => {
         '--arg1',
         'arg2',
         '--arg3',
+        '--disable-blink-features=AutomationControlled',
         'url2',
         'url3',
       ],
@@ -290,6 +294,32 @@ describe('util/extension-runners/chromium', async () => {
     await runnerInstance.exit();
   });
 
+  it("doesn't disable `AutomationControlled` when corresponding arg is passed", async () => {
+    // If the `--enable-blink-features=AutomationControlled` flag is passed,
+    // `--disable-blink-features=AutomationControlled` should not be passed.
+    const { params } = prepareExtensionRunnerParams({
+      params: {
+        args: ['--enable-blink-features=CSSVariables,AutomationControlled'],
+      },
+    });
+
+    const runnerInstance = new ChromiumExtensionRunner(params);
+    await runnerInstance.run();
+
+    sinon.assert.calledWithMatch(params.chromiumLaunch, {
+      ignoreDefaultFlags: true,
+      chromePath: undefined,
+      chromeFlags: [
+        ...DEFAULT_CHROME_FLAGS,
+        '--remote-debugging-pipe',
+        '--enable-unsafe-extension-debugging',
+        '--enable-blink-features=CSSVariables,AutomationControlled',
+      ],
+    });
+
+    await runnerInstance.exit();
+  });
+
   it('does use a random user-data-dir', async () => {
     const { params } = prepareExtensionRunnerParams({
       params: {},
@@ -334,6 +364,7 @@ describe('util/extension-runners/chromium', async () => {
           ...DEFAULT_CHROME_FLAGS,
           '--remote-debugging-pipe',
           '--enable-unsafe-extension-debugging',
+          '--disable-blink-features=AutomationControlled',
         ],
         startingUrl: undefined,
       });
@@ -375,6 +406,7 @@ describe('util/extension-runners/chromium', async () => {
             ...DEFAULT_CHROME_FLAGS,
             '--remote-debugging-pipe',
             '--enable-unsafe-extension-debugging',
+            '--disable-blink-features=AutomationControlled',
             '--profile-directory=profile',
           ],
           startingUrl: undefined,
@@ -417,6 +449,7 @@ describe('util/extension-runners/chromium', async () => {
           ...DEFAULT_CHROME_FLAGS,
           '--remote-debugging-pipe',
           '--enable-unsafe-extension-debugging',
+          '--disable-blink-features=AutomationControlled',
           `--profile-directory=${profileDirName}`,
         ],
         startingUrl: undefined,
@@ -512,6 +545,7 @@ describe('util/extension-runners/chromium', async () => {
             ...DEFAULT_CHROME_FLAGS,
             '--remote-debugging-pipe',
             '--enable-unsafe-extension-debugging',
+            '--disable-blink-features=AutomationControlled',
             '--profile-directory=profile',
           ],
           startingUrl: undefined,
@@ -548,6 +582,7 @@ describe('util/extension-runners/chromium', async () => {
         ...DEFAULT_CHROME_FLAGS,
         '--remote-debugging-pipe',
         '--enable-unsafe-extension-debugging',
+        '--disable-blink-features=AutomationControlled',
       ],
       startingUrl: undefined,
     });
@@ -558,6 +593,7 @@ describe('util/extension-runners/chromium', async () => {
         ...DEFAULT_CHROME_FLAGS,
         '--remote-debugging-pipe',
         '--load-extension=/fake/sourceDir',
+        '--disable-blink-features=AutomationControlled',
       ],
       startingUrl: undefined,
     });