better versatility for the first argument

.goreleaser.yml

@@ -30,7 +30,7 @@ brew:
     name: homebrew-tap
   folder: Formula
   homepage:  https://github.com/syntaqx/serve
-  description: `serve` is a static http server anywhere you need one.
+  description: serve is a static http server anywhere you need one.
   test: |
     system "#{bin}/serve version"
 changelog:

main.go

@@ -20,37 +20,49 @@ const version = "0.0.0-develop"
 type flags struct {
 	Host string `json:"host"`
 	Port int    `json:"port"`
+	Dir  string `json:"dir"`
 }
 
 func main() {
 	var opt flags
 	flag.StringVar(&opt.Host, "host", "", "host address to bind to")
 	flag.IntVar(&opt.Port, "port", 8080, "listening port")
+	flag.StringVar(&opt.Dir, "dir", "", "directory to serve")
 	flag.Parse()
 
 	log := log.New(os.Stderr, "[serve] ", log.LstdFlags)
 
-	// If an argument is provided, use it as the root directory.
-	dir := flag.Arg(0)
-	if len(dir) == 0 {
-		cwd, err := os.Getwd()
-		if err != nil {
-			log.Printf("unable to determine current working directory: %v\n", err)
-			os.Exit(1)
-		}
-		dir = cwd
-	}
+	// If an argument was provided, see if it's a command, or use it as opt.Dir
+	arg := flag.Arg(0)
 
 	// Version command, mostly used for testing if the binary is working.
-	if dir == "version" {
+	if arg == "version" {
 		fmt.Printf(fmt.Sprintf("serve version %s %s/%s", version, runtime.GOOS, runtime.GOARCH))
 		os.Exit(0)
 	}
 
+	// If an argument is provided, use it as the root directory.
+	if opt.Dir == "" {
+		if len(arg) == 0 {
+			cwd, err := os.Getwd()
+			if err != nil {
+				log.Printf("unable to determine current working directory: %v\n", err)
+				os.Exit(1)
+			}
+			opt.Dir = cwd
+		} else {
+			opt.Dir = arg
+		}
+	}
+
+	startHTTPServer(opt, log)
+}
+
+func startHTTPServer(opt flags, log *log.Logger) {
 	r := http.NewServeMux()
 
 	// Handler, wrapped with middleware
-	handler := http.FileServer(http.Dir(dir))
+	handler := http.FileServer(http.Dir(opt.Dir))
 	handler = Logger(log)(handler)
 	handler = CORS()(handler)
 	handler = NoCache()(handler)

main_test.go

@@ -11,6 +11,23 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestStartHTTPServer(t *testing.T) {
+	t.Skip()
+
+	t.Parallel()
+
+	assert := assert.New(t)
+
+	opt := flags{Port: 0, Dir: "."}
+
+	var b bytes.Buffer
+	log := log.New(&b, "[test] ", 0)
+
+	go startHTTPServer(opt, log)
+
+	assert.Contains(b.String(), "http server listening at")
+}
+
 func TestLogger(t *testing.T) {
 	t.Parallel()