Fix server delete tests

Now we pass a collector to `ServerDelete()`, more metrics are in the
registry and the ones we want are at the end.

Author: iainlane

metrics/server_delete_test.go

@@ -35,7 +35,8 @@ func TestServerDelete(t *testing.T) {
 	provider.EXPECT().Destroy(noContext, instance).Times(3).Return(nil)
 	provider.EXPECT().Destroy(noContext, instance).Return(errors.New("error"))
 
-	providerInst := ServerDelete(provider)
+	collector := New()
+	providerInst := ServerDelete(provider, collector)
 	for i := 0; i < 3; i++ {
 		err := providerInst.Destroy(noContext, instance)
 		if err != nil {
@@ -52,20 +53,20 @@ func TestServerDelete(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	if want, got := len(metrics), 2; want != got {
-		t.Errorf("Expect registered metric")
+	if want, got := len(metrics), 8; want != got {
+		t.Errorf("Expect registered metric %d, got %d", want, got)
 		return
 	}
-	if got, want := metrics[0].GetName(), "drone_servers_deleted"; want != got {
+	if got, want := metrics[6].GetName(), "drone_servers_deleted"; want != got {
 		t.Errorf("Expect metric name %s, got %s", want, got)
 	}
-	if got, want := metrics[0].Metric[0].Counter.GetValue(), float64(3); want != got {
+	if got, want := metrics[6].Metric[0].Counter.GetValue(), float64(3); want != got {
 		t.Errorf("Expect metric value %f, got %f", want, got)
 	}
-	if got, want := metrics[1].GetName(), "drone_servers_deleted_err"; want != got {
+	if got, want := metrics[7].GetName(), "drone_servers_deleted_err"; want != got {
 		t.Errorf("Expect metric name %s, got %s", want, got)
 	}
-	if got, want := metrics[1].Metric[0].Counter.GetValue(), float64(1); want != got {
+	if got, want := metrics[7].Metric[0].Counter.GetValue(), float64(1); want != got {
 		t.Errorf("Expect metric value %f, got %f", want, got)
 	}
 }