Make If return one validator to make usage easier

Author: wvell

errors.go

@@ -60,6 +60,18 @@ func (v Violation) Error() string {
 	return fmt.Sprintf("violation code: %s, args: %v", v.Code, v.Args)
 }
 
+type Violations []Violation
+
+func (v Violations) Error() string {
+	var errs []string
+
+	for _, err := range v {
+		errs = append(errs, err.Error())
+	}
+
+	return fmt.Sprintf("violations: %v", errs)
+}
+
 type Args map[string]any
 
 func (e Args) Add(key string, value any) Args {

examples_test.go

@@ -41,8 +41,8 @@ func ExampleCollect() {
 
 func ExampleIf() {
 	err := validate.Join(
-		validate.Field("email", "test", validate.If(true, validate.Email)...),
-		validate.Field("iban", "invalid", validate.If(false, validate.IBAN)...),
+		validate.Field("email", "test", validate.If(true, validate.Email)),
+		validate.Field("iban", "invalid", validate.If(false, validate.IBAN)),
 	)
 	printError(err)
 

validate.go

@@ -82,12 +82,25 @@ func Collect(err error) []Error {
 }
 
 // If will run the validators only if the shouldRun is true.
-func If[T any](shouldRun bool, validators ...Validator[T]) []Validator[T] {
+func If[T any](shouldRun bool, validators ...Validator[T]) Validator[T] {
 	if !shouldRun {
-		return nil
+		return func(value T) error {
+			return nil
+		}
 	}
 
-	return validators
+	return func(v T) error {
+		violations, err := validate(v, validators...)
+		if err != nil {
+			return err
+		}
+
+		if violations == nil {
+			return nil
+		}
+
+		return Violations(violations)
+	}
 }
 
 // FailFirst will run the validators in order and return the first error.
@@ -151,9 +164,12 @@ func validate[T any](
 			continue
 		}
 
-		if violation, ok := err.(*Violation); ok {
-			violations = append(violations, *violation)
-		} else {
+		switch err := err.(type) {
+		case Violations:
+			violations = append(violations, err...)
+		case *Violation:
+			violations = append(violations, *err)
+		default:
 			return nil, err
 		}
 	}

validate_test.go

@@ -31,24 +31,31 @@ func TestReturnError(t *testing.T) {
 }
 
 func TestIf(t *testing.T) {
-	// Validate true condition should run the validator.
+	// Validate true condition should run the validators.
 	err := validate.Field(
 		"first_name",
 		"John",
-		validate.If(true, failValidator[string])...,
+		validate.If(
+			true,
+			failValidatorWithCode[string]("first"),
+			failValidatorWithCode[string]("second"),
+			successValidator[string],
+		),
 	)
 	require.NotNil(t, err)
 
 	errs := validate.Collect(err)
 	require.Equal(t, 1, len(errs))
+	require.Equal(t, 2, len(errs[0].Violations))
 	require.Equal(t, "first_name", errs[0].Path)
-	require.Equal(t, "fail", errs[0].Violations[0].Code)
+	require.Equal(t, "first", errs[0].Violations[0].Code)
+	require.Equal(t, "second", errs[0].Violations[1].Code)
 
 	// Validate false condition should not run the validator.
 	err = validate.Field[string](
 		"first_name",
 		"John",
-		validate.If(false, failValidator[string])...,
+		validate.If(false, failValidator[string]),
 	)
 	require.Nil(t, err)
 }
@@ -188,3 +195,7 @@ func failValidatorWithCode[T any](code string) validate.Validator[T] {
 func failValidator[T any](value T) error {
 	return &validate.Violation{Code: "fail"}
 }
+
+func successValidator[T any](value T) error {
+	return nil
+}