fix #184, support null as number

Author: taowen

feature_reflect_native.go

@@ -441,9 +441,13 @@ type jsonNumberCodec struct {
 }
 
 func (codec *jsonNumberCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	if iter.WhatIsNext() == StringValue {
+	switch iter.WhatIsNext() {
+	case StringValue:
 		*((*json.Number)(ptr)) = json.Number(iter.ReadString())
-	} else {
+	case NilValue:
+		iter.skipFourBytes('n', 'u', 'l', 'l')
+		*((*json.Number)(ptr)) = ""
+	default:
 		*((*json.Number)(ptr)) = json.Number([]byte(iter.readNumberAsString()))
 	}
 }
@@ -464,9 +468,13 @@ type jsoniterNumberCodec struct {
 }
 
 func (codec *jsoniterNumberCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	if iter.WhatIsNext() == StringValue {
+	switch iter.WhatIsNext() {
+	case StringValue:
 		*((*Number)(ptr)) = Number(iter.ReadString())
-	} else {
+	case NilValue:
+		iter.skipFourBytes('n', 'u', 'l', 'l')
+		*((*Number)(ptr)) = ""
+	default:
 		*((*Number)(ptr)) = Number([]byte(iter.readNumberAsString()))
 	}
 }

jsoniter_int_test.go

@@ -518,6 +518,18 @@ func Test_non_numeric_as_number(t *testing.T) {
 	should.Equal("500", string(v2))
 }
 
+func Test_null_as_number(t *testing.T) {
+	should := require.New(t)
+	var v1 json.Number
+	err := json.Unmarshal([]byte(`null`), &v1)
+	should.Nil(err)
+	should.Equal("", string(v1))
+	var v2 Number
+	err = Unmarshal([]byte(`null`), &v2)
+	should.Nil(err)
+	should.Equal("", string(v2))
+}
+
 func Benchmark_jsoniter_encode_int(b *testing.B) {
 	stream := NewStream(ConfigDefault, ioutil.Discard, 64)
 	for n := 0; n < b.N; n++ {