Fix bee generate output in watch.go

This removes the output of bee generate in watch.go as it shows
the entire logger output (including the banner). Added also the ability
to catch the exec.Command error instead of returning the exit status.

watch.go

@@ -120,8 +120,6 @@ func AutoBuild(files []string, isgenerate bool) {
 	state.Lock()
 	defer state.Unlock()
 
-	logger.Info("Start building...")
-
 	os.Chdir(currpath)
 
 	cmdName := "go"
@@ -129,17 +127,20 @@ func AutoBuild(files []string, isgenerate bool) {
 		cmdName = "gopm"
 	}
 
-	var err error
+	var (
+		err    error
+		stderr bytes.Buffer
+		stdout bytes.Buffer
+	)
 	// For applications use full import path like "github.com/.../.."
 	// are able to use "go install" to reduce build time.
 	if conf.GoInstall || conf.Gopm.Install {
 		icmd := exec.Command("go", "list", "./...")
-		buf := bytes.NewBuffer([]byte(""))
-		icmd.Stdout = buf
+		icmd.Stdout = &stdout
 		icmd.Env = append(os.Environ(), "GOGC=off")
 		err = icmd.Run()
 		if err == nil {
-			list := strings.Split(buf.String(), "\n")[1:]
+			list := strings.Split(stdout.String(), "\n")[1:]
 			for _, pkg := range list {
 				if len(pkg) == 0 {
 					continue
@@ -157,12 +158,15 @@ func AutoBuild(files []string, isgenerate bool) {
 	}
 
 	if isgenerate {
+		logger.Info("Generating the docs...")
 		icmd := exec.Command("bee", "generate", "docs")
 		icmd.Env = append(os.Environ(), "GOGC=off")
-		icmd.Stdout = os.Stdout
-		icmd.Stderr = os.Stderr
-		icmd.Run()
-		logger.Info("============== Generate Docs ===================")
+		err = icmd.Run()
+		if err != nil {
+			logger.Errorf("Failed to generate the docs.")
+			return
+		}
+		logger.Success("Docs generated!")
 	}
 
 	if err == nil {
@@ -180,15 +184,14 @@ func AutoBuild(files []string, isgenerate bool) {
 
 		bcmd := exec.Command(cmdName, args...)
 		bcmd.Env = append(os.Environ(), "GOGC=off")
-		bcmd.Stdout = os.Stdout
-		bcmd.Stderr = os.Stderr
+		bcmd.Stderr = &stderr
 		err = bcmd.Run()
+		if err != nil {
+			logger.Errorf("Failed to build the application: %s", stderr.String())
+			return
+		}
 	}
 
-	if err != nil {
-		logger.Error("============== Build Failed ===================")
-		return
-	}
 	logger.Success("Built Successfully!")
 	Restart(appname)
 }