Clean up BroadcastChannel resources to fix hanging tests

change/@azure-msal-browser-cc7b4b74-d9b1-4614-ab89-ac8dfb792a3f.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "Clean up BroadcastChannel resources to fix hanging tests #8045",
+  "packageName": "@azure/msal-browser",
+  "email": "kshabelko@microsoft.com",
+  "dependentChangeType": "patch"
+}

lib/msal-browser/package.json

@@ -68,7 +68,7 @@
     "clean:coverage": "rimraf ../../.nyc_output/*",
     "lint": "eslint src --ext .ts",
     "lint:fix": "npm run lint -- --fix",
-    "test": "jest --forceExit",
+    "test": "jest",
     "test:coverage": "jest --coverage",
     "test:coverage:only": "npm run clean:coverage && npm run test:coverage",
     "build:all": "cd ../.. && npm run build --workspace=@azure/msal-common --workspace=@azure/msal-browser",

lib/msal-browser/test/utils/BridgeSetup.ts

@@ -23,4 +23,21 @@ beforeAll(() => {
         window.nestedAppAuthBridge = new MockBridge();
     }
 });
-afterAll(() => {});
+
+afterEach(() => {
+    // Clean up BroadcastChannels after each test
+    if ((global as any).forceCleanupMsalBroadcastChannels) {
+        (global as any).forceCleanupMsalBroadcastChannels();
+    } else if ((global as any).cleanupMsalBroadcastChannels) {
+        (global as any).cleanupMsalBroadcastChannels();
+    }
+});
+
+afterAll(() => {
+    // Final aggressive cleanup
+    if ((global as any).forceCleanupMsalBroadcastChannels) {
+        (global as any).forceCleanupMsalBroadcastChannels();
+    } else if ((global as any).cleanupMsalBroadcastChannels) {
+        (global as any).cleanupMsalBroadcastChannels();
+    }
+});

shared-configs/jest-config/BroadcastChannelTracker.js

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
+/**
+ * Shared BroadcastChannel tracking utility for test environments.
+ * This module provides consistent tracking and cleanup functionality
+ * across different test environments (browser/jsdom and Node.js).
+ */
+
+/**
+ * Creates a BroadcastChannel tracker for a given environment
+ * @param {Function} getBroadcastChannel - Function that returns the BroadcastChannel constructor for the environment
+ * @returns {Object} Object containing TrackedBroadcastChannel class and cleanup functions
+ */
+function createBroadcastChannelTracker(getBroadcastChannel) {
+    const activeBroadcastChannels = new Set();
+    const OriginalBroadcastChannel = getBroadcastChannel();
+
+    class TrackedBroadcastChannel extends OriginalBroadcastChannel {
+        constructor(name) {
+            super(name);
+            activeBroadcastChannels.add(this);
+        }
+
+        close() {
+            super.close();
+            activeBroadcastChannels.delete(this);
+        }
+    }
+
+    // Basic cleanup function
+    function cleanupBroadcastChannels() {
+        activeBroadcastChannels.forEach((channel) => {
+            try {
+                channel.close();
+            } catch (error) {
+                // Ignore cleanup errors
+            }
+        });
+        activeBroadcastChannels.clear();
+    }
+
+    // Enhanced cleanup function with additional reset logic
+    function forceCleanupBroadcastChannels() {
+        // First try graceful cleanup
+        cleanupBroadcastChannels();
+
+        // Add more aggressive cleanup if needed for browser environments
+        if (typeof window !== "undefined" && window.BroadcastChannel) {
+            // Reset to original BroadcastChannel to prevent further leaks
+            window.BroadcastChannel = OriginalBroadcastChannel;
+            // Then restore tracked version
+            window.BroadcastChannel = TrackedBroadcastChannel;
+        }
+
+        // Clear any remaining instances in case some weren't tracked
+        activeBroadcastChannels.clear();
+    }
+
+    return {
+        TrackedBroadcastChannel,
+        cleanupBroadcastChannels,
+        forceCleanupBroadcastChannels,
+        OriginalBroadcastChannel
+    };
+}
+
+// Node.js-specific setup for @jest-environment node tests
+// This automatically sets up BroadcastChannel tracking when this module is imported
+if (typeof window === "undefined" && typeof global !== "undefined") {
+    // Create BroadcastChannel tracker for Node.js environment
+    const {
+        TrackedBroadcastChannel,
+        cleanupBroadcastChannels
+    } = createBroadcastChannelTracker(() => {
+        const { BroadcastChannel } = require('worker_threads');
+        return BroadcastChannel;
+    });
+
+    // Replace global BroadcastChannel with tracked version
+    global.BroadcastChannel = TrackedBroadcastChannel;
+
+    // Add cleanup hooks for Node.js test environment
+    if (typeof afterEach !== "undefined" && typeof afterAll !== "undefined") {
+        afterEach(cleanupBroadcastChannels);
+        afterAll(cleanupBroadcastChannels);
+    }
+}
+
+module.exports = {
+    createBroadcastChannelTracker
+};

shared-configs/jest-config/setupGlobals.cjs

@@ -6,10 +6,22 @@
 const crypto = require("crypto");
 const { TextDecoder, TextEncoder } = require("util");
 const { BroadcastChannel, MessageChannel } = require("worker_threads");
+const { createBroadcastChannelTracker } = require("./BroadcastChannelTracker");
+
+// Create BroadcastChannel tracker for browser/jsdom environment
+const {
+    TrackedBroadcastChannel,
+    cleanupBroadcastChannels,
+    forceCleanupBroadcastChannels
+} = createBroadcastChannelTracker(() => BroadcastChannel);
+
+// Add cleanup functions to global for use in test setup files
+global.cleanupMsalBroadcastChannels = cleanupBroadcastChannels;
+global.forceCleanupMsalBroadcastChannels = forceCleanupBroadcastChannels;
 
 try {
     Object?.defineProperties(global.self, {
-        "crypto": {
+        crypto: {
             value: {
                 subtle: crypto.webcrypto.subtle,
                 getRandomValues(dataBuffer) {
@@ -18,20 +30,20 @@ try {
                 randomUUID() {
                     return crypto.randomUUID();
                 },
-            }
+            },
+        },
+        TextDecoder: {
+            value: TextDecoder,
         },
-        "TextDecoder": {
-            value: TextDecoder
+        TextEncoder: {
+            value: TextEncoder,
         },
-        "TextEncoder": {
-            value: TextEncoder
+        BroadcastChannel: {
+            value: TrackedBroadcastChannel,
         },
-        "BroadcastChannel": {
-            value: BroadcastChannel
+        MessageChannel: {
+            value: MessageChannel,
         },
-        "MessageChannel": {
-            value: MessageChannel
-        }
     });
 } catch (e) {
     // catch silently for non-browser tests