fix: accept EventListener callbacks (#175)

* fix: accept EventListener callbacks * chore: improve typing of helper functions/structures Co-authored-by: Bartlomiej Obecny <[email protected]>
open-telemetry · Oct 1, 2020 · 7e9f1ae · 7e9f1ae
1 parent d06d575
commit 7e9f1ae
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Showing 2 changed files with 36 additions and 5 deletions.
diff --git a/plugins/web/opentelemetry-plugin-user-interaction/src/userInteraction.ts b/plugins/web/opentelemetry-plugin-user-interaction/src/userInteraction.ts
@@ -50,7 +50,7 @@ export class UserInteractionPlugin extends BasePlugin<unknown> {
   private _zonePatched = false;
   // for addEventListener/removeEventListener state
   private _wrappedListeners = new WeakMap<
-    Function,
+    Function | EventListenerObject,
     Map<string, Map<HTMLElement, Function>>
   >();
   // for event bubbling
@@ -178,7 +178,7 @@ export class UserInteractionPlugin extends BasePlugin<unknown> {
   private addPatchedListener(
     on: HTMLElement,
     type: string,
-    listener: Function,
+    listener: Function | EventListenerObject,
     wrappedListener: Function
   ): boolean {
     let listener2Type = this._wrappedListeners.get(listener);
@@ -204,7 +204,7 @@ export class UserInteractionPlugin extends BasePlugin<unknown> {
   private removePatchedListener(
     on: HTMLElement,
     type: string,
-    listener: Function
+    listener: Function | EventListenerObject
   ): Function | undefined {
     const listener2Type = this._wrappedListeners.get(listener);
     if (!listener2Type) {
@@ -227,6 +227,19 @@ export class UserInteractionPlugin extends BasePlugin<unknown> {
     return patched;
   }
 
+  // utility method to deal with the Function|EventListener nature of addEventListener
+  private _invokeListener(
+    listener: Function | EventListenerObject,
+    target: any,
+    args: any[]
+  ): any {
+    if (typeof listener === 'function') {
+      return listener.apply(target, args);
+    } else {
+      return listener.handleEvent(args[0]);
+    }
+  }
+
   /**
    * This patches the addEventListener of HTMLElement to be able to
    * auto instrument the click events
@@ -258,13 +271,13 @@ export class UserInteractionPlugin extends BasePlugin<unknown> {
               plugin._eventsSpanMap.set(event, span);
             }
             return plugin._tracer.withSpan(span, () => {
-              const result = listener.apply(target, args);
+              const result = plugin._invokeListener(listener, target, args);
               // no zone so end span immediately
               span.end();
               return result;
             });
           } else {
-            return listener.apply(target, args);
+            return plugin._invokeListener(listener, target, args);
           }
         };
         if (plugin.addPatchedListener(this, type, listener, patchedListener)) {

diff --git a/plugins/web/opentelemetry-plugin-user-interaction/test/userInteraction.nozone.test.ts b/plugins/web/opentelemetry-plugin-user-interaction/test/userInteraction.nozone.test.ts
@@ -161,6 +161,24 @@ describe('UserInteractionPlugin', () => {
       assert.strictEqual(callCount, 3);
     });
 
+    it('should handle EventListener callbacks', () => {
+      let callCount = 0;
+      const listener = {
+        handleEvent(evt: Event) {
+          if (evt) {
+            callCount++;
+          }
+        },
+      };
+      document.body.addEventListener('EventListenerEvent', listener);
+      document.body.dispatchEvent(new Event('EventListenerEvent'));
+      assert.strictEqual(callCount, 1);
+      callCount = 0;
+      document.body.removeEventListener('EventListenerEvent', listener);
+      document.body.dispatchEvent(new Event('EventListenerEvent'));
+      assert.strictEqual(callCount, 0);
+    });
+
     it('should handle task without async operation', () => {
       fakeInteraction();
       assert.equal(exportSpy.args.length, 1, 'should export one span');