Merge pull request #14 from skybet/GS-953

[refs GS-953] Allow tags to work on fields that are structs

validator.go

@@ -990,10 +990,12 @@ func typeCheck(v reflect.Value, t reflect.StructField, o reflect.Value, options
 
 	var customTypeErrors Errors
 	optionsOrder := options.orderedKeys()
+	var processedTagsOnStruct bool
 	for _, validatorName := range optionsOrder {
 		validatorStruct := options[validatorName]
 		if validatefunc, ok := CustomTypeTagMap.Get(validatorName); ok {
 			delete(options, validatorName)
+			processedTagsOnStruct = true
 
 			if result := validatefunc(v.Interface(), o.Interface()); !result {
 				if len(validatorStruct.customErrorMessage) > 0 {
@@ -1182,8 +1184,18 @@ func typeCheck(v reflect.Value, t reflect.StructField, o reflect.Value, options
 		if v.IsNil() {
 			return true, nil
 		}
+		if v.Elem().Kind() == reflect.Struct && processedTagsOnStruct {
+			return true, nil
+		}
 		return typeCheck(v.Elem(), t, o, options)
 	case reflect.Struct:
+		// If a field which is a struct has validation tags, they will be custom tags because all built-in tags
+		// apply to non-struct types. processedTagsOnStruct will have been set to true in this case.
+		// The struct's fields will already have been validated on earlier, so return
+		// here so we don't validate those fields again and duplicate any validation errors.
+		if processedTagsOnStruct {
+			return true, nil
+		}
 		return ValidateStruct(v.Interface())
 	default:
 		return false, &UnsupportedTypeError{v.Type()}

validator_test.go

@@ -3535,3 +3535,117 @@ func TestSplitTag(t *testing.T) {
 	}
 
 }
+
+type NestedStruct struct {
+	AString string `valid:"alpha~AString: not alpha"`
+}
+
+type MainStruct struct {
+	Valid  bool
+	Nested NestedStruct `valid:"structtag~Nested: invalid struct"`
+}
+
+type MainStructPtr struct {
+	Valid     bool
+	NestedPtr *NestedStruct `valid:"structtagptr~Nested: invalid struct"`
+}
+
+func StructTag(v interface{}, o interface{}) bool {
+	main, ok := o.(MainStruct)
+	if !ok {
+		return false
+	}
+
+	return main.Valid
+}
+
+func StructTagPtr(v interface{}, o interface{}) bool {
+	main, ok := o.(MainStructPtr)
+	if !ok {
+		return false
+	}
+
+	return main.Valid
+}
+
+func TestValidatorTagOnAStructField(t *testing.T) {
+	var tt = []struct {
+		name               string
+		main               interface{}
+		expected           bool
+		expectedError      string
+		expectedErrorCount int
+	}{
+		{
+			name: "child tags not recursively run when parent struct tag passes validation",
+			main: MainStruct{
+				Valid: true, //this will make mainStruct return true
+				Nested: NestedStruct{
+					AString: "!!!", // this will return false from the alpha tag on the field in the struct
+				},
+			},
+			expected:           false,
+			expectedError:      "AString: not alpha",
+			expectedErrorCount: 1,
+		},
+		{
+			name: "child tags not recursively when a parent pointer-to-a-struct tag passes validation",
+			main: MainStructPtr{
+				Valid: true, //this will make mainStruct return true
+				NestedPtr: &NestedStruct{
+					AString: "!!!", // this will return false from the alpha tag on the field in the struct
+				},
+			},
+			expected:           false,
+			expectedError:      "AString: not alpha",
+			expectedErrorCount: 1,
+		},
+		{
+			name: "existing behaviour not broken - child tags not run recursively when tag on struct field is invalid",
+			main: MainStruct{
+				Valid: false, //this will make mainStruct return false
+				Nested: NestedStruct{
+					AString: "!!!", // this will return false from the alpha tag on the field in the struct
+				},
+			},
+			expected:           false,
+			expectedError:      "AString: not alpha;Nested: invalid struct",
+			expectedErrorCount: 2,
+		},
+		{
+			name: "all fields valid",
+			main: MainStruct{
+				Valid: true, //this will make mainStruct return true
+				Nested: NestedStruct{
+					AString: "aaa",
+				},
+			},
+			expected:           true,
+			expectedError:      "",
+			expectedErrorCount: 0,
+		},
+	}
+
+	CustomTypeTagMap.Set("structtag", StructTag)
+	CustomTypeTagMap.Set("structtagptr", StructTagPtr)
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+
+			actual, actualErrors := ValidateStruct(tc.main)
+			if actual != tc.expected {
+				t.Errorf("returned boolean unexpected. Want:\n%v\nHave\n%v", tc.expected, actual)
+			}
+
+			validatorErrors, _ := actualErrors.(Errors)
+
+			if validatorErrors.Error() != tc.expectedError {
+				t.Errorf("errors incorrect. Want\n%v\nHave\n%v", tc.expectedError, validatorErrors.Error())
+			}
+
+			if len(validatorErrors) != tc.expectedErrorCount {
+				t.Errorf("error count unexpected. Want\n%v\nHave\n%v", tc.expectedErrorCount, len(validatorErrors))
+			}
+		})
+	}
+}