fix: Prevent mocha tests failures when window does not have focus. (#9332)

* chore: Add puppeteer-core as a dev dependency.

* fix: Make mocha tests run in a fake-focused window.

* fix: Make `test:mocha:interactive` use the same gulp codepath as `test`.

gulpfile.mjs

@@ -45,7 +45,11 @@ import {
   publishBeta,
   recompile,
 } from './scripts/gulpfiles/release_tasks.mjs';
-import {generators, test} from './scripts/gulpfiles/test_tasks.mjs';
+import {
+  generators,
+  interactiveMocha,
+  test,
+} from './scripts/gulpfiles/test_tasks.mjs';
 
 const clean = parallel(cleanBuildDir, cleanReleaseDir);
 
@@ -80,6 +84,7 @@ export {
   clean,
   test,
   generators as testGenerators,
+  interactiveMocha,
   buildAdvancedCompilationTest,
   createRC as gitCreateRC,
   docs,

package-lock.json

@@ -51,6 +51,7 @@
         "patch-package": "^8.0.0",
         "prettier": "^3.3.3",
         "prettier-plugin-organize-imports": "^4.0.0",
+        "puppeteer-core": "^24.17.0",
         "readline-sync": "^1.4.10",
         "rimraf": "^5.0.0",
         "typescript": "^5.3.3",
@@ -1282,18 +1283,18 @@
       }
     },
     "node_modules/@puppeteer/browsers": {
-      "version": "2.10.4",
+      "version": "2.10.7",
-      "resolved": "https://registry.npmjs.org/@puppeteer/browsers/-/browsers-2.10.4.tgz",
+      "resolved": "https://registry.npmjs.org/@puppeteer/browsers/-/browsers-2.10.7.tgz",
-      "integrity": "sha512-9DxbZx+XGMNdjBynIs4BRSz+M3iRDeB7qRcAr6UORFLphCIM2x3DXgOucvADiifcqCE4XePFUKcnaAMyGbrDlQ==",
+      "integrity": "sha512-wHWLkQWBjHtajZeqCB74nsa/X70KheyOhySYBRmVQDJiNj0zjZR/naPCvdWjMhcG1LmjaMV/9WtTo5mpe8qWLw==",
       "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
-        "debug": "^4.4.0",
+        "debug": "^4.4.1",
         "extract-zip": "^2.0.1",
         "progress": "^2.0.3",
         "proxy-agent": "^6.5.0",
-        "semver": "^7.7.1",
+        "semver": "^7.7.2",
-        "tar-fs": "^3.0.8",
+        "tar-fs": "^3.1.0",
         "yargs": "^17.7.2"
       },
       "bin": {
@@ -2960,6 +2961,20 @@
         "fsevents": "~2.3.2"
       }
     },
+    "node_modules/chromium-bidi": {
+      "version": "8.0.0",
+      "resolved": "https://registry.npmjs.org/chromium-bidi/-/chromium-bidi-8.0.0.tgz",
+      "integrity": "sha512-d1VmE0FD7lxZQHzcDUCKZSNRtRwISXDsdg4HjdTR5+Ll5nQ/vzU12JeNmupD6VWffrPSlrnGhEWlLESKH3VO+g==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "mitt": "^3.0.1",
+        "zod": "^3.24.1"
+      },
+      "peerDependencies": {
+        "devtools-protocol": "*"
+      }
+    },
     "node_modules/ci-info": {
       "version": "3.8.0",
       "resolved": "https://registry.npmjs.org/ci-info/-/ci-info-3.8.0.tgz",
@@ -3612,6 +3627,13 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/devtools-protocol": {
+      "version": "0.0.1475386",
+      "resolved": "https://registry.npmjs.org/devtools-protocol/-/devtools-protocol-0.0.1475386.tgz",
+      "integrity": "sha512-RQ809ykTfJ+dgj9bftdeL2vRVxASAuGU+I9LEx9Ij5TXU5HrgAQVmzi72VA+mkzscE12uzlRv5/tWWv9R9J1SA==",
+      "dev": true,
+      "license": "BSD-3-Clause"
+    },
     "node_modules/diff": {
       "version": "7.0.0",
       "resolved": "https://registry.npmjs.org/diff/-/diff-7.0.0.tgz",
@@ -6895,6 +6917,13 @@
         "node": ">=16 || 14 >=14.17"
       }
     },
+    "node_modules/mitt": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/mitt/-/mitt-3.0.1.tgz",
+      "integrity": "sha512-vKivATfr97l2/QBCYAkXYDbrIWPM2IIKEl7YPhjCvKlG3kE2gm+uBo6nEXK3M5/Ffh/FLpKExzOQ3JJoJGFKBw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/mkdirp": {
       "version": "0.5.6",
       "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.6.tgz",
@@ -7925,6 +7954,24 @@
         "node": ">=6"
       }
     },
+    "node_modules/puppeteer-core": {
+      "version": "24.17.0",
+      "resolved": "https://registry.npmjs.org/puppeteer-core/-/puppeteer-core-24.17.0.tgz",
+      "integrity": "sha512-RYOBKFiF+3RdwIZTEacqNpD567gaFcBAOKTT7742FdB1icXudrPI7BlZbYTYWK2wgGQUXt9Zi1Yn+D5PmCs4CA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@puppeteer/browsers": "2.10.7",
+        "chromium-bidi": "8.0.0",
+        "debug": "^4.4.1",
+        "devtools-protocol": "0.0.1475386",
+        "typed-query-selector": "^2.12.0",
+        "ws": "^8.18.3"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/qs": {
       "version": "6.14.0",
       "resolved": "https://registry.npmjs.org/qs/-/qs-6.14.0.tgz",
@@ -8993,9 +9040,9 @@
       }
     },
     "node_modules/tar-fs": {
-      "version": "3.0.9",
+      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/tar-fs/-/tar-fs-3.0.9.tgz",
+      "resolved": "https://registry.npmjs.org/tar-fs/-/tar-fs-3.1.0.tgz",
-      "integrity": "sha512-XF4w9Xp+ZQgifKakjZYmFdkLoSWd34VGKcsTCwlNWM7QG3ZbaxnTsaBwnjFZqHRf/rROxaR8rXnbtwdvaDI+lA==",
+      "integrity": "sha512-5Mty5y/sOF1YWj1J6GiBodjlDc05CUR8PKXrsnFAiSG0xA+GHeWLovaZPYUDXkH/1iKRf2+M5+OrRgzC7O9b7w==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -9212,6 +9259,13 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/typed-query-selector": {
+      "version": "2.12.0",
+      "resolved": "https://registry.npmjs.org/typed-query-selector/-/typed-query-selector-2.12.0.tgz",
+      "integrity": "sha512-SbklCd1F0EiZOyPiW192rrHZzZ5sBijB6xM+cpmrwDqObvdtunOHHIk9fCGsoK5JVIYXoyEp4iEdE3upFH3PAg==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/typedarray": {
       "version": "0.0.6",
       "resolved": "https://registry.npmjs.org/typedarray/-/typedarray-0.0.6.tgz",
@@ -9773,9 +9827,10 @@
       "dev": true
     },
     "node_modules/ws": {
-      "version": "8.18.0",
+      "version": "8.18.3",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-8.18.0.tgz",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.18.3.tgz",
-      "integrity": "sha512-8VbfWfHLbbwu3+N6OKsOMpBdT4kXPDDB9cJk2bJ6mh9ucxdlnNvH1e+roYkKmN9Nxw2yjz7VzeO9oOz2zJ04Pw==",
+      "integrity": "sha512-PEIGCY5tSlUt50cqyMXfCzX+oOPqN0vuGqWzbcJ2xvnkzkq46oOpz7dQaTDBdfICb4N14+GARUDw2XV2N4tvzg==",
+      "license": "MIT",
       "engines": {
         "node": ">=10.0.0"
       },
@@ -10029,6 +10084,16 @@
       "dependencies": {
         "safe-buffer": "~5.2.0"
       }
+    },
+    "node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
     }
   }
 }

package.json

@@ -45,7 +45,7 @@
     "test": "gulp test",
     "test:browser": "cd tests/browser && npx mocha",
     "test:generators": "gulp testGenerators",
-    "test:mocha:interactive": "npm run build && concurrently -n tsc,server \"tsc --watch --preserveWatchOutput --outDir \"build/src\" --declarationDir \"build/declarations\"\" \"http-server ./ -o /tests/mocha/index.html -c-1\"",
+    "test:mocha:interactive": "npm run build && concurrently -n tsc,server \"tsc --watch --preserveWatchOutput --outDir \"build/src\" --declarationDir \"build/declarations\"\" \"gulp interactiveMocha\"",
     "test:compile:advanced": "gulp buildAdvancedCompilationTest --debug",
     "updateGithubPages": "npm ci && gulp gitUpdateGithubPages"
   },
@@ -138,6 +138,7 @@
     "patch-package": "^8.0.0",
     "prettier": "^3.3.3",
     "prettier-plugin-organize-imports": "^4.0.0",
+    "puppeteer-core": "^24.17.0",
     "readline-sync": "^1.4.10",
     "rimraf": "^5.0.0",
     "typescript": "^5.3.3",

scripts/gulpfiles/test_tasks.mjs

@@ -257,9 +257,9 @@ async function metadata() {
  * Run Mocha tests inside a browser.
  * @return {Promise} Asynchronous result.
  */
-async function mocha() {
+async function mocha(exitOnCompletion = true) {
   return runTestTask('mocha', async () => {
-    const result = await runMochaTestsInBrowser().catch(e => {
+    const result = await runMochaTestsInBrowser(exitOnCompletion).catch(e => {
       throw e;
     });
     if (result) {
@@ -269,6 +269,14 @@ async function mocha() {
   });
 }
 
+/**
+ * Run Mocha tests inside a browser and keep the browser open upon completion.
+ * @return {Promise} Asynchronous result.
+ */
+export async function interactiveMocha() {
+  return mocha(false);
+}
+
 /**
  * Helper method for comparison file.
  * @param {string} file1 First target file.

tests/mocha/webdriver.js

@@ -15,9 +15,12 @@ const {posixPath} = require('../../scripts/helpers');
  * Runs the Mocha tests in this directory in Chrome. It uses webdriverio to
  * launch Chrome and load index.html. Outputs a summary of the test results
  * to the console.
+ *
+ * @param {boolean} exitOnCompletetion True if the browser should automatically
+ *     quit after tests have finished running.
  * @return {number} 0 on success, 1 on failure.
  */
-async function runMochaTestsInBrowser() {
+async function runMochaTestsInBrowser(exitOnCompletion = true) {
   const options = {
     capabilities: {
       browserName: 'chrome',
@@ -45,6 +48,17 @@ async function runMochaTestsInBrowser() {
   console.log('Loading URL: ' + url);
   await browser.url(url);
 
+  // Toggle the devtools setting to emulate focus, so that the window will
+  // always act as if it has focus regardless of the state of the window manager
+  // or operating system. This improves the reliability of FocusManager-related
+  // tests.
+  const puppeteer = await browser.getPuppeteer();
+  await browser.call(async () => {
+    const page = (await puppeteer.pages())[0];
+    const session = await page.createCDPSession();
+    await session.send('Emulation.setFocusEmulationEnabled', { enabled: true });
+  });
+
   await browser.waitUntil(async() => {
     const elem = await browser.$('#failureCount');
     const text = await elem.getAttribute('tests_failed');
@@ -74,7 +88,7 @@ async function runMochaTestsInBrowser() {
   if (parseInt(numOfFailure) !== 0) {
     return 1;
   }
-  await browser.deleteSession();
+  if (exitOnCompletion) await browser.deleteSession();
   return 0;
 }