add json test (#1031)

encoding/json/json.go

@@ -39,15 +39,14 @@ func (codec) Marshal(v interface{}) ([]byte, error) {
 
 func (codec) Unmarshal(data []byte, v interface{}) error {
 	rv := reflect.ValueOf(v)
-	for rv.Kind() == reflect.Ptr {
+	if rv.Kind() == reflect.Ptr {
 		if rv.IsNil() {
 			rv.Set(reflect.New(rv.Type().Elem()))
 		}
-		rv = rv.Elem()
 	}
 	if m, ok := v.(proto.Message); ok {
 		return UnmarshalOptions.Unmarshal(data, m)
-	} else if m, ok := reflect.Indirect(reflect.ValueOf(v)).Interface().(proto.Message); ok {
+	} else if m, ok := reflect.Indirect(rv).Interface().(proto.Message); ok {
 		return UnmarshalOptions.Unmarshal(data, m)
 	}
 	return json.Unmarshal(data, v)

encoding/json/json_test.go

@@ -0,0 +1,80 @@
+package json
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+type testEmbed struct {
+	Level1a int `json:"a"`
+	Level1b int `json:"b"`
+	Level1c int `json:"c"`
+}
+
+type testMessage struct {
+	Field1 string     `json:"a"`
+	Field2 string     `json:"b"`
+	Field3 string     `json:"c"`
+	Embed  *testEmbed `json:"embed,omitempty"`
+}
+
+func TestJSON_Marshal(t *testing.T) {
+	tests := []struct {
+		input  interface{}
+		expect string
+	}{
+		{
+			input:  &testMessage{},
+			expect: `{"a":"","b":"","c":""}`,
+		},
+		{
+			input:  &testMessage{Field1: "a", Field2: "b", Field3: "c"},
+			expect: `{"a":"a","b":"b","c":"c"}`,
+		},
+	}
+	for _, v := range tests {
+		data, err := (codec{}).Marshal(v.input)
+		if err != nil {
+			t.Errorf("marshal(%#v): %s", v.input, err)
+		}
+		if got, want := string(data), v.expect; got != want {
+			if strings.Contains(want, "\n") {
+				t.Errorf("marshal(%#v):\nHAVE:\n%s\nWANT:\n%s", v.input, got, want)
+			} else {
+				t.Errorf("marshal(%#v):\nhave %#q\nwant %#q", v.input, got, want)
+			}
+		}
+	}
+}
+
+func TestJSON_Unmarshal(t *testing.T) {
+	p := &testMessage{}
+	tests := []struct {
+		input  string
+		expect interface{}
+	}{
+		{
+			input:  `{"a":"","b":"","c":""}`,
+			expect: &testMessage{},
+		},
+		{
+			input:  `{"a":"a","b":"b","c":"c"}`,
+			expect: &p,
+		},
+	}
+	for _, v := range tests {
+		want := []byte(v.input)
+		err := (codec{}).Unmarshal(want, &v.expect)
+		if err != nil {
+			t.Errorf("marshal(%#v): %s", v.input, err)
+		}
+		got, err := codec{}.Marshal(v.expect)
+		if err != nil {
+			t.Errorf("marshal(%#v): %s", v.input, err)
+		}
+		if !bytes.Equal(got, want) {
+			t.Errorf("marshal(%#v):\nhave %#q\nwant %#q", v.input, got, want)
+		}
+	}
+}