fix: gjson customized slice unmarshal failed

binding/gjson/gjson.go

@@ -38,7 +38,10 @@ import (
 	"github.com/bytedance/go-tagexpr/v2/binding/gjson/internal/rt"
 )
 
-var programCache = caching.CreateProgramCache()
+var (
+	programCache = caching.CreateProgramCache()
+	unmarshalerInterface = reflect.TypeOf((*json.Unmarshaler)(nil)).Elem()
+)
 
 func init() {
 	gjson.DisableModifiers = true
@@ -97,7 +100,13 @@ func assign(jsval gjson.Result, goval reflect.Value) (err error) {
 			goval.Set(reflect.ValueOf(data))
 		} else {
 			if !jsval.IsArray() {
-				return nil
+				// canAddr: true, implement unmarshaler : true   -> continue
+				// canAddr: true, implement unmarshaler : false  -> return
+				// canAddr: false, implement unmarshaler : true  -> return
+				// canAddr: false, implement unmarshaler : false -> return
+				if !goval.CanAddr() || !goval.Addr().Type().Implements(unmarshalerInterface) {
+					return nil
+				}
 			}
 			jsvals := jsval.Array()
 			slice := reflect.MakeSlice(t, len(jsvals), len(jsvals))

binding/gjson/gjson_test.go

@@ -236,3 +236,43 @@ func getFiledInfoWithMap(t reflect.Type) map[string][]int {
 	}
 	return sf
 }
+
+
+// MarshalJSON to output non base64 encoded []byte
+func (j ByteSlice) MarshalJSON() ([]byte, error) {
+	if len(j) == 0 {
+		return []byte("null"), nil
+	}
+
+	return json.RawMessage(j).MarshalJSON()
+}
+
+// UnmarshalJSON to deserialize []byte
+func (j *ByteSlice) UnmarshalJSON(b []byte) error {
+	result := json.RawMessage{}
+	err := result.UnmarshalJSON(b)
+	*j = ByteSlice(result)
+	return err
+}
+
+type ByteSlice []byte
+
+func TestCustomizedGjsonUnmarshal(t *testing.T) {
+	str := `{"h1":{"h2":1}}`
+	type F struct {
+		H ByteSlice `json:"h1"`
+	}
+
+	obj := F{}
+	err := Unmarshal([]byte(str), &obj)
+
+	assert.NoError(t, err)
+	assert.Equal(t, "{\"h2\":1}", string(obj.H))
+
+	obj2 := F{}
+	err = json.Unmarshal([]byte(str), &obj2)
+	assert.NoError(t, err)
+	assert.Equal(t, "{\"h2\":1}", string(obj2.H))
+
+	assert.Equal(t, obj.H, obj2.H)
+}