Repository: go-playground/validator
Pull request #847 (2021-10-14 00:16:12)

added excluded_if/excluded_unless tags + tests
## Fixes Or Enhances

Adds `excluded_if` and `excluded_unless` tags with tests.

**Make sure that you've checked the boxes below before you submit PR:**
- [x] Tests exist or have been written that cover this particular change.

@go-playground/validator-maintainers

agbishop: This would be useful, can someone please review this?

Patch:
diff --git a/README.md b/README.md
index 6712e95..f25649a 100644
--- a/README.md
+++ b/README.md
@@ -219,6 +219,8 @@ Baked-in Validations
 | required_with_all | Required With All |
 | required_without | Required Without |
 | required_without_all | Required Without All |
+| excluded_if | Excluded If |
+| excluded_unless | Excluded Unless |
 | excluded_with | Excluded With |
 | excluded_with_all | Excluded With All |
 | excluded_without | Excluded Without |
diff --git a/baked_in.go b/baked_in.go
index 7868b66..36a410b 100644
--- a/baked_in.go
+++ b/baked_in.go
@@ -75,6 +75,8 @@ var (
 		"required_with_all":             requiredWithAll,
 		"required_without":              requiredWithout,
 		"required_without_all":          requiredWithoutAll,
+		"excluded_if":                   excludedIf,
+		"excluded_unless":               excludedUnless,
 		"excluded_with":                 excludedWith,
 		"excluded_with_all":             excludedWithAll,
 		"excluded_without":              excludedWithout,
@@ -1542,6 +1544,22 @@ func requiredIf(fl FieldLevel) bool {
 	return hasValue(fl)
 }
 
+// excludedIf is the validation function
+// The field under validation must not be present or is empty only if all the other specified fields are equal to the value following with the specified field.
+func excludedIf(fl FieldLevel) bool {
+	params := parseOneOfParam2(fl.Param())
+	if len(params)%2 != 0 {
+		panic(fmt.Sprintf("Bad param number for excluded_if %s", fl.FieldName()))
+	}
+
+	for i := 0; i < len(params); i += 2 {
+		if !requireCheckFieldValue(fl, params[i], params[i+1], false) {
+			return false
+		}
+	}
+	return true
+}
+
 // requiredUnless is the validation function
 // The field under validation must be present and not empty only unless all the other specified fields are equal to the value following with the specified field.
 func requiredUnless(fl FieldLevel) bool {
@@ -1558,6 +1576,21 @@ func requiredUnless(fl FieldLevel) bool {
 	return hasValue(fl)
 }
 
+// excludedUnless is the validation function
+// The field under validation must not be present or is empty unless all the other specified fields are equal to the value following with the specified field.
+func excludedUnless(fl FieldLevel) bool {
+	params := parseOneOfParam2(fl.Param())
+	if len(params)%2 != 0 {
+		panic(fmt.Sprintf("Bad param number for excluded_unless %s", fl.FieldName()))
+	}
+	for i := 0; i < len(params); i += 2 {
+		if !requireCheckFieldValue(fl, params[i], params[i+1], false) {
+			return true
+		}
+	}
+	return !hasValue(fl)
+}
+
 // excludedWith is the validation function
 // The field under validation must not be present or is empty if any of the other specified fields are present.
 func excludedWith(fl FieldLevel) bool {
diff --git a/doc.go b/doc.go
index b284c37..6cf6208 100644
--- a/doc.go
+++ b/doc.go
@@ -349,6 +349,40 @@ Example:
 	// require the field if the Field1 and Field2 is not present:
 	Usage: required_without_all=Field1 Field2
 
+Excluded If
+
+The field under validation must not be present or not empty only if all
+the other specified fields are equal to the value following the specified
+field. For strings ensures value is not "". For slices, maps, pointers,
+interfaces, channels and functions ensures the value is not nil.
+
+	Usage: excluded_if
+
+Examples:
+
+	// exclude the field if the Field1 is equal to the parameter given:
+	Usage: excluded_if=Field1 foobar
+
+	// exclude the field if the Field1 and Field2 is equal to the value respectively:
+	Usage: excluded_if=Field1 foo Field2 bar
+
+Excluded Unless
+
+The field under validation must not be present or empty unless all
+the other specified fields are equal to the value following the specified
+field. For strings ensures value is not "". For slices, maps, pointers,
+interfaces, channels and functions ensures the value is not nil.
+
+	Usage: excluded_unless
+
+Examples:
+
+	// exclude the field unless the Field1 is equal to the parameter given:
+	Usage: excluded_unless=Field1 foobar
+
+	// exclude the field unless the Field1 and Field2 is equal to the value respectively:
+	Usage: excluded_unless=Field1 foo Field2 bar
+
 Is Default
 
 This validates that the value is the default value and is almost the
diff --git a/validator_instance.go b/validator_instance.go
index 973964f..6d66060 100644
--- a/validator_instance.go
+++ b/validator_instance.go
@@ -33,6 +33,8 @@ const (
 	excludedWithoutTag    = "excluded_without"
 	excludedWithTag       = "excluded_with"
 	excludedWithAllTag    = "excluded_with_all"
+	excludedIfTag         = "excluded_if"
+	excludedUnlessTag     = "excluded_unless"
 	skipValidationTag     = "-"
 	diveTag               = "dive"
 	keysTag               = "keys"
@@ -120,7 +122,7 @@ func New() *Validate {
 		switch k {
 		// these require that even if the value is nil that the validation should run, omitempty still overrides this behaviour
 		case requiredIfTag, requiredUnlessTag, requiredWithTag, requiredWithAllTag, requiredWithoutTag, requiredWithoutAllTag,
-			excludedWithTag, excludedWithAllTag, excludedWithoutTag, excludedWithoutAllTag:
+			excludedIfTag, excludedUnlessTag, excludedWithTag, excludedWithAllTag, excludedWithoutTag, excludedWithoutAllTag:
 			_ = v.registerValidation(k, wrapFunc(val), true, true)
 		default:
 			// no need to error check here, baked in will always be valid


Test patch:
diff --git a/validator_test.go b/validator_test.go
index 3730fb9..4da0de6 100644
--- a/validator_test.go
+++ b/validator_test.go
@@ -10675,6 +10675,145 @@ func TestRequiredWithoutAll(t *testing.T) {
 	AssertError(t, errs, "Field2", "Field2", "Field2", "Field2", "required_without_all")
 }
 
+func TestExcludedIf(t *testing.T) {
+	validate := New()
+	type Inner struct {
+		Field *string
+	}
+
+	test1 := struct {
+		FieldE  string  `validate:"omitempty" json:"field_e"`
+		FieldER *string `validate:"excluded_if=FieldE test" json:"field_er"`
+	}{
+		FieldE: "test",
+	}
+	errs := validate.Struct(test1)
+	Equal(t, errs, nil)
+
+	test2 := struct {
+		FieldE  string `validate:"omitempty" json:"field_e"`
+		FieldER string `validate:"excluded_if=FieldE test" json:"field_er"`
+	}{
+		FieldE: "notest",
+	}
+	errs = validate.Struct(test2)
+	NotEqual(t, errs, nil)
+	ve := errs.(ValidationErrors)
+	Equal(t, len(ve), 1)
+	AssertError(t, errs, "FieldER", "FieldER", "FieldER", "FieldER", "excluded_if")
+
+	shouldError := "shouldError"
+	test3 := struct {
+		Inner  *Inner
+		FieldE string `validate:"omitempty" json:"field_e"`
+		Field1 int    `validate:"excluded_if=Inner.Field test" json:"field_1"`
+	}{
+		Inner: &Inner{Field: &shouldError},
+	}
+	errs = validate.Struct(test3)
+	NotEqual(t, errs, nil)
+	ve = errs.(ValidationErrors)
+	Equal(t, len(ve), 1)
+	AssertError(t, errs, "Field1", "Field1", "Field1", "Field1", "excluded_if")
+
+	shouldPass := "test"
+	test4 := struct {
+		Inner  *Inner
+		FieldE string `validate:"omitempty" json:"field_e"`
+		Field1 int    `validate:"excluded_if=Inner.Field test" json:"field_1"`
+	}{
+		Inner: &Inner{Field: &shouldPass},
+	}
+	errs = validate.Struct(test4)
+	Equal(t, errs, nil)
+
+	// Checks number of params in struct tag is correct
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("panicTest should have panicked!")
+		}
+	}()
+	fieldVal := "panicTest"
+	panicTest := struct {
+		Inner  *Inner
+		Field1 string `validate:"excluded_if=Inner.Field" json:"field_1"`
+	}{
+		Inner: &Inner{Field: &fieldVal},
+	}
+	_ = validate.Struct(panicTest)
+}
+
+func TestExcludedUnless(t *testing.T) {
+	validate := New()
+	type Inner struct {
+		Field *string
+	}
+
+	fieldVal := "test"
+	test := struct {
+		FieldE  string `validate:"omitempty" json:"field_e"`
+		FieldER string `validate:"excluded_unless=FieldE test" json:"field_er"`
+	}{
+		FieldE:  "notest",
+		FieldER: "filled",
+	}
+	errs := validate.Struct(test)
+	Equal(t, errs, nil)
+
+	test2 := struct {
+		FieldE  string `validate:"omitempty" json:"field_e"`
+		FieldER string `validate:"excluded_unless=FieldE test" json:"field_er"`
+	}{
+		FieldE:  "test",
+		FieldER: "filled",
+	}
+	errs = validate.Struct(test2)
+	NotEqual(t, errs, nil)
+	ve := errs.(ValidationErrors)
+	Equal(t, len(ve), 1)
+	AssertError(t, errs, "FieldER", "FieldER", "FieldER", "FieldER", "excluded_unless")
+
+	shouldError := "test"
+	test3 := struct {
+		Inner  *Inner
+		Field1 string `validate:"excluded_unless=Inner.Field test" json:"field_1"`
+	}{
+		Inner:  &Inner{Field: &shouldError},
+		Field1: "filled",
+	}
+	errs = validate.Struct(test3)
+	NotEqual(t, errs, nil)
+	ve = errs.(ValidationErrors)
+	Equal(t, len(ve), 1)
+	AssertError(t, errs, "Field1", "Field1", "Field1", "Field1", "excluded_unless")
+
+	shouldPass := "shouldPass"
+	test4 := struct {
+		Inner  *Inner
+		FieldE string `validate:"omitempty" json:"field_e"`
+		Field1 string `validate:"excluded_unless=Inner.Field test" json:"field_1"`
+	}{
+		Inner:  &Inner{Field: &shouldPass},
+		Field1: "filled",
+	}
+	errs = validate.Struct(test4)
+	Equal(t, errs, nil)
+
+	// Checks number of params in struct tag is correct
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("panicTest should have panicked!")
+		}
+	}()
+	panicTest := struct {
+		Inner  *Inner
+		Field1 string `validate:"excluded_unless=Inner.Field" json:"field_1"`
+	}{
+		Inner: &Inner{Field: &fieldVal},
+	}
+	_ = validate.Struct(panicTest)
+}
+
 func TestLookup(t *testing.T) {
 	type Lookup struct {
 		FieldA *string `json:"fieldA,omitempty" validate:"required_without=FieldB"`
@@ -11460,7 +11599,7 @@ func TestSemverFormatValidation(t *testing.T) {
 		}
 	}
 }
-  
+
 func TestRFC1035LabelFormatValidation(t *testing.T) {
 	tests := []struct {
 		value    string `validate:"dns_rfc1035_label"`