fix: Clean up BatchUploader timers and event listeners on re-init

src/batchUploader.ts

@@ -47,6 +47,10 @@ export class BatchUploader {
     private uploader: AsyncUploader;
     private lastASTEventTime: number = 0;
     private readonly AST_DEBOUNCE_MS: number = 1000; // 1 second debounce
+    private uploadIntervalTimerId: ReturnType<typeof setTimeout> | null = null;
+    private exitHandler: (() => void) | null = null;
+    private visibilityChangeHandler: (() => void) | null = null;
+    private destroyed = false;
 
     /**
      * Creates an instance of a BatchUploader
@@ -105,6 +109,31 @@ export class BatchUploader {
         this.addEventListeners();
     }
 
+    /**
+     * Cleans up timers and event listeners to prevent leaks when the SDK
+     * is re-initialized (e.g. between tests or on repeated init calls).
+     */
+    public destroy(): void {
+        this.destroyed = true;
+
+        if (this.uploadIntervalTimerId !== null) {
+            clearTimeout(this.uploadIntervalTimerId);
+            this.uploadIntervalTimerId = null;
+        }
+
+        if (this.visibilityChangeHandler) {
+            document.removeEventListener('visibilitychange', this.visibilityChangeHandler);
+        }
+
+        if (this.exitHandler) {
+            window.removeEventListener('beforeunload', this.exitHandler);
+            window.removeEventListener('pagehide', this.exitHandler);
+        }
+
+        this.exitHandler = null;
+        this.visibilityChangeHandler = null;
+    }
+
     private isOfflineStorageAvailable(): boolean {
         const {
             _Helpers: { getFeatureFlag },
@@ -218,12 +247,17 @@ export class BatchUploader {
             // Then trigger the upload with beacon
             _this.prepareAndUpload(false, _this.isBeaconAvailable());
         };
-        // visibility change is a document property, not window
-        document.addEventListener('visibilitychange', () => {
+
+        this.exitHandler = handleExit;
+
+        this.visibilityChangeHandler = () => {
             if (document.visibilityState === 'hidden') {
                 handleExit();
             }
-        });
+        };
+
+        // visibility change is a document property, not window
+        document.addEventListener('visibilitychange', this.visibilityChangeHandler);
         window.addEventListener('beforeunload', handleExit);
         window.addEventListener('pagehide', handleExit);
     }
@@ -240,7 +274,7 @@ export class BatchUploader {
         triggerFuture: boolean = false,
         useBeacon: boolean = false
     ): void {
-        setTimeout(() => {
+        this.uploadIntervalTimerId = setTimeout(() => {
             this.prepareAndUpload(triggerFuture, useBeacon);
         }, this.uploadIntervalMillis);
     }
@@ -445,7 +479,7 @@ export class BatchUploader {
             this.batchesQueuedForProcessing = [];
         }
 
-        if (triggerFuture) {
+        if (triggerFuture && !this.destroyed) {
             this.triggerUploadInterval(triggerFuture, false);
         }
     }

src/mp-instance.ts

@@ -126,12 +126,12 @@
     this._instanceName = instanceName;
     this._NativeSdkHelpers = new NativeSdkHelpers(this);
     this._SessionManager = new SessionManager(this);
     this._Persistence = new Persistence(this);
     this._Helpers = new Helpers(this);
     this._Events = new Events(this);
     this._CookieSyncManager = new CookieSyncManager(this);
     this._ServerModel = new ServerModel(this);
     this._Ecommerce = new Ecommerce(this);
     this._ForwardingStatsUploader = new ForwardingStatsUploader(this);
     this._Consent = new Consent(this);
     this._IdentityAPIClient = new IdentityAPIClient(this);
@@ -189,7 +189,7 @@
     this.ProductActionType = ProductActionType;
 
 
     this._Identity = new Identity(this);
     this.Identity = this._Identity.IdentityAPI;
     this.generateHash = this._Helpers.generateHash;
 
@@ -198,9 +198,9 @@
     this.getDeviceId = this._Persistence.getDeviceId;
 
     if (typeof window !== 'undefined') {
         if (window.mParticle && window.mParticle.config) {
             if (window.mParticle.config.hasOwnProperty('rq')) {
                 this._preInit.readyQueue = window.mParticle.config.rq;
             }
         }
     }
@@ -1446,6 +1446,11 @@
     const kitBlocker = createKitBlocker(config, mpInstance);
     const { getFeatureFlag } = mpInstance._Helpers;
 
+    // Destroy previous batch uploader to prevent leaked timers and event listeners
+    if (mpInstance._APIClient?.uploader) {
+        mpInstance._APIClient.uploader.destroy();
+    }
+
     mpInstance._APIClient = new APIClient(mpInstance, kitBlocker);
     mpInstance._Forwarders = new Forwarders(mpInstance, kitBlocker);
     mpInstance._Store.processConfig(config);
@@ -1648,7 +1653,7 @@
     mpInstance._ErrorReportingDispatcher.logger = mpInstance.Logger;
     mpInstance._LoggingDispatcher.logger = mpInstance.Logger;
     mpInstance._Store = new Store(config, mpInstance, apiKey);
     window.mParticle.Store = mpInstance._Store;
     mpInstance.Logger.verbose(StartingInitialization);
 
     // Initialize CookieConsentManager with privacy flags from launcherOptions

test/jest/batchUploader.spec.ts

@@ -53,6 +53,7 @@ describe('BatchUploader', () => {
     });
 
     afterEach(() => {
+        batchUploader.destroy();
         jest.useRealTimers();
         global.fetch = originalFetch;
     });

test/src/config/setup.ts

@@ -30,6 +30,13 @@ beforeEach(function() {
         clearInterval(forwardingStatsTimer);
         mParticleSDK._forwardingStatsTimer = 0;
     }
+
+    // Destroy the batch uploader to prevent leaked timers and event listeners
+    // from accumulating across tests
+    const uploader = mpInstance?._APIClient?.uploader;
+    if (uploader) {
+        uploader.destroy();
+    }
 
     // mocha can't clean up after itself, so this lets
     // tests mock the current user and restores in between runs.