grpc: fixed BoardListWatch streaming call (#2664)

* grpc: fixed BoardListWatch streaming call

* Added integration test

* Fixed also existing calls to BoardListWatch

Author: cmaglie

Diff for: commands/service_board_list.go

@@ -318,5 +318,6 @@ func (s *arduinoCoreServerImpl) BoardListWatch(req *rpc.BoardListWatchRequest, s
 		}
 	}()
 
+	<-stream.Context().Done()
 	return nil
 }

Diff for: internal/cli/arguments/port.go

@@ -89,17 +89,14 @@ func (p *Port) GetPort(ctx context.Context, instance *rpc.Instance, srv rpc.Ardu
 	}
 	logrus.WithField("port", address).Tracef("Upload port")
 
-	ctx, cancel := context.WithCancel(ctx)
+	ctx, cancel := context.WithTimeout(ctx, p.timeout.Get())
 	defer cancel()
 
 	stream, watcher := commands.BoardListWatchProxyToChan(ctx)
-	err := srv.BoardListWatch(&rpc.BoardListWatchRequest{Instance: instance}, stream)
+	go func() {
+		_ = srv.BoardListWatch(&rpc.BoardListWatchRequest{Instance: instance}, stream)
+	}()
 
-	if err != nil {
-		return nil, err
-	}
-
-	deadline := time.After(p.timeout.Get())
 	for {
 		select {
 		case portEvent := <-watcher:
@@ -111,7 +108,7 @@ func (p *Port) GetPort(ctx context.Context, instance *rpc.Instance, srv rpc.Ardu
 				return port, nil
 			}
 
-		case <-deadline:
+		case <-ctx.Done():
 			// No matching port found
 			if protocol == "" {
 				return &rpc.Port{

Diff for: internal/cli/board/list.go

@@ -91,10 +91,12 @@ func runListCommand(ctx context.Context, srv rpc.ArduinoCoreServiceServer, watch
 
 func watchList(ctx context.Context, inst *rpc.Instance, srv rpc.ArduinoCoreServiceServer) {
 	stream, eventsChan := commands.BoardListWatchProxyToChan(ctx)
-	err := srv.BoardListWatch(&rpc.BoardListWatchRequest{Instance: inst}, stream)
-	if err != nil {
-		feedback.Fatal(i18n.Tr("Error detecting boards: %v", err), feedback.ErrNetwork)
-	}
+	go func() {
+		err := srv.BoardListWatch(&rpc.BoardListWatchRequest{Instance: inst}, stream)
+		if err != nil {
+			feedback.Fatal(i18n.Tr("Error detecting boards: %v", err), feedback.ErrNetwork)
+		}
+	}()
 
 	// This is done to avoid printing the header each time a new event is received
 	if feedback.GetFormat() == feedback.Text {

Diff for: internal/integrationtest/daemon/daemon_test.go

@@ -91,6 +91,24 @@ func TestArduinoCliDaemon(t *testing.T) {
 
 	testWatcher()
 	testWatcher()
+
+	{
+		// Test that the watcher stays open until the grpc call is canceled
+
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*2)
+		defer cancel()
+
+		start := time.Now()
+		watcher, err := grpcInst.BoardListWatch(ctx)
+		require.NoError(t, err)
+		for {
+			_, err := watcher.Recv()
+			if err != nil {
+				break
+			}
+		}
+		require.Greater(t, time.Since(start), 2*time.Second)
+	}
 }
 
 func TestDaemonAutoUpdateIndexOnFirstInit(t *testing.T) {