Fix equivalence test (#208)

* Revert "Use endpoint instead of connection in equivalence_test (#207)"

This reverts commit b2a517b.

* Make test result more accurate

equivalence_test.go

@@ -132,10 +132,17 @@ func TestEquivalenceStatsVsMetricsUploads(t *testing.T) {
 	server, addr, doneFn := createFakeServer(t)
 	defer doneFn()
 
+	// Now create a gRPC connection to the fake Stackdriver server.
+	conn, err := grpc.Dial(addr, grpc.WithInsecure())
+	if err != nil {
+		t.Fatalf("Failed to make a gRPC connection to the server: %v", err)
+	}
+	defer conn.Close()
+
 	// Finally create the OpenCensus stats exporter
 	exporterOptions := Options{
 		ProjectID:               "equivalence",
-		MonitoringClientOptions: []option.ClientOption{option.WithEndpoint(addr)},
+		MonitoringClientOptions: []option.ClientOption{option.WithGRPCConn(conn)},
 
 		// Setting this time delay threshold to a very large value
 		// so that batching is performed deterministically and flushing is
@@ -342,6 +349,14 @@ func TestEquivalenceStatsVsMetricsUploads(t *testing.T) {
 		stackdriverMetricDescriptorsFromMetricsPb = append(stackdriverMetricDescriptorsFromMetricsPb, sdmd)
 	})
 
+	if len(stackdriverTimeSeriesFromMetrics) == 0 {
+		t.Fatalf("Failed to export timeseries with metrics")
+	}
+
+	if len(stackdriverTimeSeriesFromMetricsPb) == 0 {
+		t.Fatalf("Failed to export timeseries with metrics pb")
+	}
+
 	// The results should be equal now
 	if diff := cmpTSReqs(stackdriverTimeSeriesFromMetricsPb, stackdriverTimeSeriesFromMetrics); diff != "" {
 		t.Fatalf("Unexpected CreateTimeSeriesRequests -FromMetricsPb +FromMetrics: %s", diff)