engine: keep trying to watch for Docker Compose events if we didn't a…

…ctually start watching the first time (#1257)

* engine: keep trying to watch for Docker Compose events if we didn't actually start watching the first time

* test

internal/engine/docker_compose_event_watcher.go

@@ -30,7 +30,6 @@ func (w *DockerComposeEventWatcher) OnChange(ctx context.Context, st store.RStor
 	if !w.needsWatch(st) {
 		return
 	}
-	w.watching = true
 
 	state := st.RLockState()
 	configPath := state.DockerComposeConfigPath()
@@ -41,6 +40,7 @@ func (w *DockerComposeEventWatcher) OnChange(ctx context.Context, st store.RStor
 		return
 	}
 
+	w.watching = true
 	ch, err := w.startWatch(ctx, configPath)
 	if err != nil {
 		err = errors.Wrap(err, "Subscribing to docker-compose events")

internal/engine/upper_test.go

@@ -1868,6 +1868,29 @@ func TestDockerComposeEventSetsStatus(t *testing.T) {
 	})
 }
 
+func TestDockerComposeStartsEventWatcher(t *testing.T) {
+	f := newTestFixture(t)
+	_, m := f.setupDCFixture()
+
+	// Actual behavior is that we init with zero manifests, and add in manifests
+	// after Tiltfile loads. Mimic that here.
+	f.Start([]model.Manifest{}, true)
+	time.Sleep(10 * time.Millisecond)
+
+	f.store.Dispatch(ConfigsReloadedAction{Manifests: []model.Manifest{m}})
+	f.waitForCompletedBuildCount(1)
+
+	// Is DockerComposeEventWatcher watching for events??
+	err := f.dcc.SendEvent(dcContainerEvtForManifest(m, dockercompose.ActionCreate))
+	if err != nil {
+		f.T().Fatal(err)
+	}
+
+	f.WaitUntilManifestState("resource status = 'In Progress'", m.ManifestName(), func(ms store.ManifestState) bool {
+		return ms.DCResourceState().Status == dockercompose.StatusInProg
+	})
+}
+
 func TestDockerComposeRecordsBuildLogs(t *testing.T) {
 	f := newTestFixture(t)
 	m, _ := f.setupDCFixture()