refactor: use regexp to get root path

main_test.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRootDir(t *testing.T) {
+	projectDirName := "go-root-dir"
+	dir := RootDir(projectDirName)
+	require.NotEmpty(t, dir)
+	require.Equal(t, strings.Split(dir, "/")[len(strings.Split(dir, "/"))-1], projectDirName)
+}
+
+func TestRootDirError(t *testing.T) {
+	require.Empty(t, RootDir(""))
+	require.Empty(t, RootDir("aaa"))
+}