bugfix: fix map decode (go-kratos#2979)

* fix map decode

* fix lint

* fix lint

Author: tonybase

encoding/form/proto_decode.go

@@ -20,7 +20,9 @@ import (
 	"google.golang.org/protobuf/types/known/wrapperspb"
 )
 
-var ErrInvalidFormatMapKey = errors.New("invalid formatting for map key")
+const fieldSeparater = "."
+
+var errInvalidFormatMapKey = errors.New("invalid formatting for map key")
 
 // DecodeValues decode url value into proto message.
 func DecodeValues(msg proto.Message, values url.Values) error {
@@ -91,6 +93,8 @@ func getFieldDescriptor(v protoreflect.Message, fieldName string) protoreflect.F
 			fd = getDescriptorByFieldAndName(fields, strings.TrimSuffix(fieldName, "[]"))
 		default:
 			// If the type is map, you get the string "map[kratos]", where "map" is a field of proto and "kratos" is a key of map
+			// Use symbol . for separating fields/structs. (eg. structfield.field)
+			// ref: https://github.com/go-playground/form
 			field, _, err := parseURLQueryMapKey(fieldName)
 			if err != nil {
 				break
@@ -357,8 +361,17 @@ func parseURLQueryMapKey(key string) (string, string, error) {
 		startIndex = strings.IndexByte(key, '[')
 		endIndex   = strings.IndexByte(key, ']')
 	)
+	if startIndex < 0 {
+		//nolint:gomnd
+		values := strings.SplitN(key, fieldSeparater, 2)
+		//nolint:gomnd
+		if len(values) != 2 {
+			return "", "", errInvalidFormatMapKey
+		}
+		return values[0], values[1], nil
+	}
 	if startIndex <= 0 || startIndex >= endIndex || len(key) != endIndex+1 {
-		return "", "", ErrInvalidFormatMapKey
+		return "", "", errInvalidFormatMapKey
 	}
 	return key[:startIndex], key[startIndex+1 : endIndex], nil
 }

encoding/form/proto_decode_test.go

@@ -97,6 +97,24 @@ func TestPopulateMapField(t *testing.T) {
 	}
 }
 
+func TestPopulateMapSepField(t *testing.T) {
+	query, err := url.ParseQuery("map.name=kratos")
+	if err != nil {
+		t.Fatal(err)
+	}
+	comp := &complex.Complex{}
+	field := getFieldDescriptor(comp.ProtoReflect(), "map")
+	// Fill the comp map field with the url query values
+	err = populateMapField(field, comp.ProtoReflect().Mutable(field).Map(), []string{"map.name"}, query["map.name"])
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Get the comp map field value
+	if query["map.name"][0] != comp.Map["name"] {
+		t.Errorf("want: %s, got: %s", query, comp.Map)
+	}
+}
+
 func TestParseField(t *testing.T) {
 	tests := []struct {
 		name                    string
@@ -230,31 +248,31 @@ func TestParseURLQueryMapKey(t *testing.T) {
 			fieldName: "map[]", field: "map", fieldKey: "", err: nil,
 		},
 		{
-			fieldName: "", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "[[]", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "[[]", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "map[kratos]=", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "map[kratos]=", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "[kratos]", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "[kratos]", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "map", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "map", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "map[", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "map[", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "]kratos[", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "]kratos[", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "[kratos", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "[kratos", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 		{
-			fieldName: "kratos]", field: "", fieldKey: "", err: ErrInvalidFormatMapKey,
+			fieldName: "kratos]", field: "", fieldKey: "", err: errInvalidFormatMapKey,
 		},
 	}
 	for _, test := range tests {