Ensure node.StartApp always returns.

pkg/visor/rpc_test.go

@@ -1,6 +1,7 @@
 package visor
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"os"
@@ -124,7 +125,7 @@ func TestStartStopApp(t *testing.T) {
 
 	err = rpc.StopApp(&unknownApp, nil)
 	require.Error(t, err)
-	assert.Equal(t, ErrUnknownApp, err)
+	assert.Equal(t, errors.New("app is either non-existent, or is already stopped"), err)
 
 	require.NoError(t, rpc.StopApp(&app, nil))
 	time.Sleep(100 * time.Millisecond)

pkg/visor/visor.go

@@ -400,18 +400,25 @@ func (node *Node) Apps() []*AppState {
 
 // StartApp starts registered App.
 func (node *Node) StartApp(appName string) error {
-	for _, app := range node.appsConf {
-		if app.App == appName {
-			startCh := make(chan struct{})
-			go func(app AppConfig) {
-				if err := node.SpawnApp(&app, startCh); err != nil {
-					node.logger.Warnf("Failed to start app %s: %s", appName, err)
-				}
-			}(app)
-
-			<-startCh
-			return nil
+	for _, appC := range node.appsConf {
+		if appC.App != appName {
+			continue
 		}
+
+		done := make(chan struct{}, 1)
+		var err error
+
+		go func(appC AppConfig) {
+			if err = node.SpawnApp(&appC, done); err != nil {
+				done <- struct{}{}
+				node.logger.Warnf("Failed to start app %s: %s", appName, err)
+			}
+		}(appC)
+
+		<-done
+		close(done)
+
+		return err
 	}
 
 	return ErrUnknownApp