chore: export MarshalIndent api in root (bytedance#668)

Author: liuq19

api.go

@@ -157,6 +157,13 @@ func Marshal(val interface{}) ([]byte, error) {
     return ConfigDefault.Marshal(val)
 }
 
+// MarshalIndent is like Marshal but applies Indent to format the output.
+// Each JSON element in the output will begin on a new line beginning with prefix
+// followed by one or more copies of indent according to the indentation nesting.
+func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
+    return ConfigDefault.MarshalIndent(v, prefix, indent)
+}
+
 // MarshalString returns the JSON encoding string of v.
 func MarshalString(val interface{}) (string, error) {
     return ConfigDefault.MarshalToString(val)

api_test.go

@@ -49,3 +49,21 @@ func TestValid(t *testing.T) {
         require.Equal(t, tc.expected, Valid([]byte(tc.data)), tc.data)
     }
 }
+
+
+func TestIdent(t *testing.T) {
+    foo := struct {
+        Name string
+        Age  int
+    }{
+        Name: "sonic",
+        Age:  20,
+    }
+
+    out, err := MarshalIndent(&foo, "", "  ")
+    require.Nil(t, err)
+    require.Equal(t, `{
+  "Name": "sonic",
+  "Age": 20
+}`, string(out))
+}