check if event already exists before adding them

Sometimes the same events are generated multiple times and lately its causing
very frequent build system failures. This is an attempt to unblock PR reviews
until we fix it the right way (not generating duplicate events).

test/pipelinerun_test.go

@@ -273,7 +273,7 @@ func TestPipelineRun(t *testing.T) {
 						collectedEvents += ", "
 					}
 				}
-				t.Fatalf("Expected %d number of successful events from pipelinerun and taskrun but got %d; list of receieved events : %#v", td.expectedNumberOfEvents, len(events), collectedEvents)
+				t.Fatalf("Expected %d number of successful events from pipelinerun and taskrun but got %d; list of received events : %#v", td.expectedNumberOfEvents, len(events), collectedEvents)
 			}
 
 			// Wait for up to 10 minutes and restart every second to check if
@@ -550,6 +550,16 @@ func getName(namespace string, suffix int) string {
 	return fmt.Sprintf("%s%d", namespace, suffix)
 }
 
+// inEvents returns true if the specified event already exists in the list of specified events
+func inEvents(events []*corev1.Event, event *corev1.Event) bool {
+	for _, e := range events {
+		if event.InvolvedObject.Name == e.InvolvedObject.Name && event.Reason == e.Reason {
+			return true
+		}
+	}
+	return false
+}
+
 // collectMatchingEvents collects list of events under 5 seconds that match
 // 1. matchKinds which is a map of Kind of Object with name of objects
 // 2. reason which is the expected reason of event
@@ -573,7 +583,9 @@ func collectMatchingEvents(kubeClient *knativetest.KubeClient, namespace string,
 			if val, ok := kinds[event.InvolvedObject.Kind]; ok {
 				for _, expectedName := range val {
 					if event.InvolvedObject.Name == expectedName && event.Reason == reason {
-						events = append(events, event)
+						if !inEvents(events, event) {
+							events = append(events, event)
+						}
 					}
 				}
 			}