fix: issue go-kratos#2782

encoding/proto/proto.go

@@ -3,7 +3,9 @@
 package proto
 
 import (
+	"errors"
 	"google.golang.org/protobuf/proto"
+	"reflect"
 
 	"github.com/go-kratos/kratos/v2/encoding"
 )
@@ -23,9 +25,26 @@ func (codec) Marshal(v interface{}) ([]byte, error) {
 }
 
 func (codec) Unmarshal(data []byte, v interface{}) error {
-	return proto.Unmarshal(data, v.(proto.Message))
+	pm, err := getProtoMessage(v)
+	if err != nil {
+		return err
+	}
+	return proto.Unmarshal(data, pm)
 }
 
 func (codec) Name() string {
 	return Name
 }
+
+func getProtoMessage(v interface{}) (proto.Message, error) {
+	if d, ok := v.(proto.Message); ok {
+		return d, nil
+	}
+	e := reflect.ValueOf(v)
+	if e.Kind() != reflect.Ptr {
+		return nil, errors.New("not proto message")
+	}
+
+	e = e.Elem()
+	return getProtoMessage(e.Interface())
+}

encoding/proto/proto_test.go

@@ -44,3 +44,61 @@ func TestCodec(t *testing.T) {
 		t.Errorf("Hobby should be %s, but got %s", res.Hobby, model.Hobby)
 	}
 }
+
+func TestCodec2(t *testing.T) {
+	c := new(codec)
+
+	model := testData.TestModel{
+		Id:    1,
+		Name:  "kratos",
+		Hobby: []string{"study", "eat", "play"},
+	}
+
+	m, err := c.Marshal(&model)
+	if err != nil {
+		t.Errorf("Marshal() should be nil, but got %s", err)
+	}
+
+	var res testData.TestModel
+	rp := &res
+
+	err = c.Unmarshal(m, &rp)
+	if err != nil {
+		t.Errorf("Unmarshal() should be nil, but got %s", err)
+	}
+	if !reflect.DeepEqual(res.Id, model.Id) {
+		t.Errorf("ID should be %d, but got %d", res.Id, model.Id)
+	}
+	if !reflect.DeepEqual(res.Name, model.Name) {
+		t.Errorf("Name should be %s, but got %s", res.Name, model.Name)
+	}
+	if !reflect.DeepEqual(res.Hobby, model.Hobby) {
+		t.Errorf("Hobby should be %s, but got %s", res.Hobby, model.Hobby)
+	}
+}
+
+func Test_getProtoMessage(t *testing.T) {
+	p := &testData.TestModel{Id: 1}
+	type args struct {
+		v interface{}
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{name: "test1", args: args{v: &testData.TestModel{}}, wantErr: false},
+		{name: "test2", args: args{v: testData.TestModel{}}, wantErr: true},
+		{name: "test3", args: args{v: &p}, wantErr: false},
+		{name: "test4", args: args{v: 1}, wantErr: true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := getProtoMessage(tt.args.v)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("getProtoMessage() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+		})
+	}
+}