Merge pull request #20 from itchyny/fix-escape-key-marshal

Fix escaping keys in MarshalJSON

Author: iancoleman

orderedmap.go

@@ -315,25 +315,24 @@ func sliceStringToSliceWithOrderedMaps(valueStr string, newSlice *[]interface{})
 }
 
 func (o OrderedMap) MarshalJSON() ([]byte, error) {
-	s := "{"
-	for _, k := range o.keys {
+	var buf bytes.Buffer
+	buf.WriteByte('{')
+	encoder := json.NewEncoder(&buf)
+	encoder.SetEscapeHTML(o.escapeHTML)
+	for i, k := range o.keys {
+		if i > 0 {
+			buf.WriteByte(',')
+		}
 		// add key
-		kEscaped := strings.Replace(k, `"`, `\"`, -1)
-		s = s + `"` + kEscaped + `":`
+		if err := encoder.Encode(k); err != nil {
+			return nil, err
+		}
+		buf.WriteByte(':')
 		// add value
-		v := o.values[k]
-		buffer := new(bytes.Buffer)
-		encoder := json.NewEncoder(buffer)
-		encoder.SetEscapeHTML(o.escapeHTML)
-		err := encoder.Encode(v)
-		if err != nil {
-			return []byte{}, err
+		if err := encoder.Encode(o.values[k]); err != nil {
+			return nil, err
 		}
-		s = s + buffer.String() + ","
-	}
-	if len(o.keys) > 0 {
-		s = s[0 : len(s)-1]
 	}
-	s = s + "}"
-	return []byte(s), nil
+	buf.WriteByte('}')
+	return buf.Bytes(), nil
 }

orderedmap_test.go

@@ -132,16 +132,16 @@ func TestMarshalJSON(t *testing.T) {
 	v.Set("e", 1)
 	v.Set("a", 2)
 	o.Set("orderedmap", v)
-	// double quote in key
-	o.Set(`test"ing`, 9)
+	// escape key
+	o.Set("test\n\r\t\\\"ing", 9)
 	// convert to json
 	b, err := json.Marshal(o)
 	if err != nil {
 		t.Error("Marshalling json", err)
 	}
 	s := string(b)
 	// check json is correctly ordered
-	if s != `{"number":4,"string":"x","specialstring":"\\.\u003c\u003e[]{}_-","z":1,"a":2,"b":3,"slice":["1",1],"orderedmap":{"e":1,"a":2},"test\"ing":9}` {
+	if s != `{"number":4,"string":"x","specialstring":"\\.\u003c\u003e[]{}_-","z":1,"a":2,"b":3,"slice":["1",1],"orderedmap":{"e":1,"a":2},"test\n\r\t\\\"ing":9}` {
 		t.Error("JSON Marshal value is incorrect", s)
 	}
 	// convert to indented json
@@ -165,7 +165,7 @@ func TestMarshalJSON(t *testing.T) {
     "e": 1,
     "a": 2
   },
-  "test\"ing": 9
+  "test\n\r\t\\\"ing": 9
 }`
 	if si != ei {
 		fmt.Println(ei)