More robust max pending event handling.

Author: kinyoklion

packages/telemetry/browser-telemetry/__tests__/BrowserTelemetryImpl.test.ts

@@ -208,3 +208,37 @@ it('unregisters collectors on close', () => {
 
   expect(mockCollector.unregister).toHaveBeenCalled();
 });
+
+it('logs event dropped message when maxPendingEvents is reached', () => {
+  const mockLogger = {
+    warn: jest.fn(),
+  };
+  const telemetry = new BrowserTelemetryImpl({
+    ...defaultOptions,
+    breadcrumbs: {
+      maxBreadcrumbs: 2,
+      click: false,
+      keyboardInput: false,
+      http: {
+        instrumentFetch: false,
+        instrumentXhr: false,
+      },
+      evaluations: false,
+      flagChange: false,
+    },
+    maxPendingEvents: 2,
+    logger: mockLogger,
+  });
+  telemetry.captureError(new Error('Test error'));
+  expect(mockLogger.warn).not.toHaveBeenCalled();
+  telemetry.captureError(new Error('Test error 2'));
+  expect(mockLogger.warn).not.toHaveBeenCalled();
+
+  telemetry.captureError(new Error('Test error 3'));
+  expect(mockLogger.warn).toHaveBeenCalledWith(
+    'LaunchDarkly - Browser Telemetry: Maximim pending events reached. Old events will be dropped until the SDK' +
+    ' client is registered.');
+
+  telemetry.captureError(new Error('Test error 4'));
+  expect(mockLogger.warn).toHaveBeenCalledTimes(1)
+});

packages/telemetry/browser-telemetry/src/BrowserTelemetryImpl.ts

@@ -83,6 +83,9 @@ export default class BrowserTelemetryImpl implements BrowserTelemetry {
 
   private _logger: MinLogger;
 
+  // Used to ensure we only log the event dropped message once.
+  private _eventsDropped: boolean = false;
+
   constructor(private _options: ParsedOptions) {
     configureTraceKit(_options.stack);
 
@@ -168,11 +171,14 @@ export default class BrowserTelemetryImpl implements BrowserTelemetry {
     if (this._client === undefined) {
       this._pendingEvents.push({ type, data: event });
       if (this._pendingEvents.length > this._maxPendingEvents) {
-        this._logger.warn(
-          prefixLog(
-            `Dropping ${this._pendingEvents.length - this._maxPendingEvents} pending events.`,
-          ),
-        );
+        if (!this._eventsDropped) {
+          this._eventsDropped = true;
+          this._logger.warn(
+            prefixLog(
+              `Maximim pending events reached. Old events will be dropped until the SDK client is registered.`,
+            ),
+          );
+        }
         this._pendingEvents.shift();
       }
     }
@@ -184,20 +190,20 @@ export default class BrowserTelemetryImpl implements BrowserTelemetry {
 
     const data: ErrorData = validException
       ? {
-          type: exception.name || exception.constructor?.name || GENERIC_EXCEPTION,
-          // Only coalesce null/undefined, not empty.
-          message: exception.message ?? MISSING_MESSAGE,
-          stack: parse(exception, this._options.stack),
-          breadcrumbs: [...this._breadcrumbs],
-          sessionId: this._sessionId,
-        }
+        type: exception.name || exception.constructor?.name || GENERIC_EXCEPTION,
+        // Only coalesce null/undefined, not empty.
+        message: exception.message ?? MISSING_MESSAGE,
+        stack: parse(exception, this._options.stack),
+        breadcrumbs: [...this._breadcrumbs],
+        sessionId: this._sessionId,
+      }
       : {
-          type: GENERIC_EXCEPTION,
-          message: NULL_EXCEPTION_MESSAGE,
-          stack: { frames: [] },
-          breadcrumbs: [...this._breadcrumbs],
-          sessionId: this._sessionId,
-        };
+        type: GENERIC_EXCEPTION,
+        message: NULL_EXCEPTION_MESSAGE,
+        stack: { frames: [] },
+        breadcrumbs: [...this._breadcrumbs],
+        sessionId: this._sessionId,
+      };
     this._capture(ERROR_KEY, data);
   }
 

packages/telemetry/browser-telemetry/src/collectors/http/fetchDecorator.ts

@@ -77,7 +77,7 @@ export default function decorateFetch(callback: (breadcrumb: HttpBreadcrumb) =>
       return response;
     });
   }
-  wrapper.prototype = originalFetch.prototype;
+  wrapper.prototype = originalFetch?.prototype;
 
   try {
     // Use defineProperty to prevent this value from being enumerable.