Fix NewSketch crash when directories.user is not set (#2862)

* integrationtest: add dameon NewSketch tests

* commands: fix panic when calling `NewSketch` with empty directories.user

We were calling directly a function that lookup for user definied
settings. In case an user did not set explictly the directory it would
return an empty string causing a panic. Instead we should have used a
dedicated function `UserDir` that uses a fallback the default
directories.user

Author: alessio-perugini

Diff for: commands/service_sketch_new.go

@@ -48,7 +48,7 @@ func (s *arduinoCoreServerImpl) NewSketch(ctx context.Context, req *rpc.NewSketc
 	if len(req.GetSketchDir()) > 0 {
 		sketchesDir = req.GetSketchDir()
 	} else {
-		sketchesDir = s.settings.GetString("directories.User")
+		sketchesDir = s.settings.UserDir().String()
 	}
 
 	if err := validateSketchName(req.GetSketchName()); err != nil {

Diff for: internal/integrationtest/arduino-cli.go

@@ -710,3 +710,14 @@ func (inst *ArduinoCLIInstance) BoardIdentify(ctx context.Context, props map[str
 	resp, err := inst.cli.daemonClient.BoardIdentify(ctx, req)
 	return resp, err
 }
+
+// NewSketch calls the "NewSketch" gRPC method.
+func (inst *ArduinoCLIInstance) NewSketch(ctx context.Context, sketchName, sketchDir string, overwrite bool) (*commands.NewSketchResponse, error) {
+	req := &commands.NewSketchRequest{
+		SketchName: sketchName,
+		SketchDir:  sketchDir,
+		Overwrite:  overwrite,
+	}
+	logCallf(">>> NewSketch(%+v)\n", req)
+	return inst.cli.daemonClient.NewSketch(ctx, req)
+}

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

@@ -614,6 +614,22 @@ func TestDaemonUserAgent(t *testing.T) {
 	}
 }
 
+func TestDaemonCreateSketch(t *testing.T) {
+	// https://github.com/arduino/arduino-cli/issues/2861
+
+	env, cli := integrationtest.CreateEnvForDaemon(t)
+	defer env.CleanUp()
+
+	grpcInst := cli.Create()
+	require.NoError(t, grpcInst.Init("", "", func(ir *commands.InitResponse) {
+		fmt.Printf("INIT> %v\n", ir.GetMessage())
+	}))
+
+	sketchName := "test_sketch.ino"
+	_, err := grpcInst.NewSketch(context.Background(), sketchName, "", false)
+	require.NoError(t, err)
+}
+
 func analyzeUpdateIndexClient(t *testing.T, cl commands.ArduinoCoreService_UpdateIndexClient) (map[string]*commands.DownloadProgressEnd, error) {
 	analyzer := NewDownloadProgressAnalyzer(t)
 	for {