Add support for validating map types

binding/binding.go

@@ -52,9 +52,9 @@ type BindingUri interface {
 // https://github.com/go-playground/validator/tree/v10.6.1.
 type StructValidator interface {
 	// ValidateStruct can receive any kind of type and it should never panic, even if the configuration is not right.
-	// If the received type is a slice|array, the validation should be performed travel on every element.
+	// If the received type is a slice/array/map, the validation should be performed on every element.
-	// If the received type is not a struct or slice|array, any validation should be skipped and nil must be returned.
+	// If the received type is not a struct or slice/array/map, any validation should be skipped and nil must be returned.
-	// If the received type is a struct or pointer to a struct, the validation should be performed.
+	// If the received type is a pointer to a struct/slice/array/map, the validation should be performed.
 	// If the struct is not valid or the validation itself fails, a descriptive error should be returned.
 	// Otherwise nil must be returned.
 	ValidateStruct(interface{}) error

binding/binding_nomsgpack.go

@@ -50,8 +50,9 @@ type BindingUri interface {
 // https://github.com/go-playground/validator/tree/v10.6.1.
 type StructValidator interface {
 	// ValidateStruct can receive any kind of type and it should never panic, even if the configuration is not right.
-	// If the received type is not a struct, any validation should be skipped and nil must be returned.
+	// If the received type is a slice/array/map, the validation should be performed on every element.
-	// If the received type is a struct or pointer to a struct, the validation should be performed.
+	// If the received type is not a struct or slice/array/map, any validation should be skipped and nil must be returned.
+	// If the received type is a pointer to a struct/slice/array/map, the validation should be performed.
 	// If the struct is not valid or the validation itself fails, a descriptive error should be returned.
 	// Otherwise nil must be returned.
 	ValidateStruct(interface{}) error

binding/default_validator.go

@@ -41,9 +41,33 @@ func (fe sliceFieldError) Unwrap() error {
 	return fe.FieldError
 }
 
+// MapFieldError is returned for invalid map values.
+// It extends validator.FieldError with the key of the failing value.
+type MapFieldError interface {
+	validator.FieldError
+	Key() interface{}
+}
+
+type mapFieldError struct {
+	validator.FieldError
+	key interface{}
+}
+
+func (fe mapFieldError) Key() interface{} {
+	return fe.key
+}
+
+func (fe mapFieldError) Error() string {
+	return fmt.Sprintf("[%v]: %s", fe.key, fe.FieldError.Error())
+}
+
+func (fe mapFieldError) Unwrap() error {
+	return fe.FieldError
+}
+
 var _ StructValidator = &defaultValidator{}
 
-// ValidateStruct receives any kind of type, but validates only structs, pointers, slices, and arrays.
+// ValidateStruct receives any kind of type, but validates only structs, pointers, slices, arrays, and maps.
 func (v *defaultValidator) ValidateStruct(obj interface{}) error {
 	if obj == nil {
 		return nil
@@ -56,8 +80,8 @@ func (v *defaultValidator) ValidateStruct(obj interface{}) error {
 	case reflect.Struct:
 		return v.validateStruct(obj)
 	case reflect.Slice, reflect.Array:
-		count := value.Len()
 		var errs validator.ValidationErrors
+		count := value.Len()
 		for i := 0; i < count; i++ {
 			if err := v.ValidateStruct(value.Index(i).Interface()); err != nil {
 				for _, fieldError := range err.(validator.ValidationErrors) { // nolint: errorlint
@@ -69,6 +93,19 @@ func (v *defaultValidator) ValidateStruct(obj interface{}) error {
 			return errs
 		}
 		return nil
+	case reflect.Map:
+		var errs validator.ValidationErrors
+		for _, key := range value.MapKeys() {
+			if err := v.ValidateStruct(value.MapIndex(key).Interface()); err != nil {
+				for _, fieldError := range err.(validator.ValidationErrors) { // nolint: errorlint
+					errs = append(errs, mapFieldError{fieldError, key.Interface()})
+				}
+			}
+		}
+		if len(errs) > 0 {
+			return errs
+		}
+		return nil
 	default:
 		return nil
 	}

binding/default_validator_test.go

@@ -21,6 +21,20 @@ func TestSliceFieldError(t *testing.T) {
 	assert.Equal(t, fe, errors.Unwrap(err))
 }
 
+func TestMapFieldError(t *testing.T) {
+	var fe validator.FieldError = dummyFieldError{msg: "test error"}
+
+	var err MapFieldError = mapFieldError{fe, "test key"}
+	assert.Equal(t, "test key", err.Key())
+	assert.Equal(t, "[test key]: test error", err.Error())
+	assert.Equal(t, fe, errors.Unwrap(err))
+
+	err = mapFieldError{fe, 123}
+	assert.Equal(t, 123, err.Key())
+	assert.Equal(t, "[123]: test error", err.Error())
+	assert.Equal(t, fe, errors.Unwrap(err))
+}
+
 type dummyFieldError struct {
 	validator.FieldError
 	msg string
@@ -61,6 +75,18 @@ func TestDefaultValidator(t *testing.T) {
 		{"validate *[]*struct failed-1", &defaultValidator{}, &[]*exampleStruct{{A: "123456789", B: 1}}, true},
 		{"validate *[]*struct failed-2", &defaultValidator{}, &[]*exampleStruct{{A: "12345678", B: 0}}, true},
 		{"validate *[]*struct passed", &defaultValidator{}, &[]*exampleStruct{{A: "12345678", B: 1}}, false},
+		{"validate map[string]struct failed-1", &defaultValidator{}, map[string]exampleStruct{"x": {A: "123456789", B: 1}}, true},
+		{"validate map[string]struct failed-2", &defaultValidator{}, map[string]exampleStruct{"x": {A: "12345678", B: 0}}, true},
+		{"validate map[string]struct passed", &defaultValidator{}, map[string]exampleStruct{"x": {A: "12345678", B: 1}}, false},
+		{"validate map[string]*struct failed-1", &defaultValidator{}, map[string]*exampleStruct{"x": {A: "123456789", B: 1}}, true},
+		{"validate map[string]*struct failed-2", &defaultValidator{}, map[string]*exampleStruct{"x": {A: "12345678", B: 0}}, true},
+		{"validate map[string]*struct passed", &defaultValidator{}, map[string]*exampleStruct{"x": {A: "12345678", B: 1}}, false},
+		{"validate *map[string]struct failed-1", &defaultValidator{}, &map[string]exampleStruct{"x": {A: "123456789", B: 1}}, true},
+		{"validate *map[string]struct failed-2", &defaultValidator{}, &map[string]exampleStruct{"x": {A: "12345678", B: 0}}, true},
+		{"validate *map[string]struct passed", &defaultValidator{}, &map[string]exampleStruct{"x": {A: "12345678", B: 1}}, false},
+		{"validate *map[string]*struct failed-1", &defaultValidator{}, &map[string]*exampleStruct{"x": {A: "123456789", B: 1}}, true},
+		{"validate *map[string]*struct failed-2", &defaultValidator{}, &map[string]*exampleStruct{"x": {A: "12345678", B: 0}}, true},
+		{"validate *map[string]*struct passed", &defaultValidator{}, &map[string]*exampleStruct{"x": {A: "12345678", B: 1}}, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {