Fix requiredfields linter to respect OmitEmpty Ignore policy

When the requiredfields linter is configured with omitempty policy set to
'Ignore', violations for missing omitempty tags were still reported because
checkFieldPropertiesWithoutOmitEmpty was hardcoded to use
OmitEmptyPolicySuggestFix instead of respecting the configured policy.

Use s.omitEmptyPolicy and skip subsequent pointer checks when policy is
Ignore, since those checks assume omitempty will be added.

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>

Author: saschagrunert

pkg/analysis/optionalfields/testdata/src/c/a.go

@@ -32,3 +32,18 @@ func TestDefaultConfiguration(t *testing.T) {
 
 	analysistest.RunWithSuggestedFixes(t, testdata, a, "a")
 }
+
+func TestOmitEmptyIgnorePolicy(t *testing.T) {
+	testdata := analysistest.TestData()
+
+	a, err := requiredfields.Initializer().Init(&requiredfields.RequiredFieldsConfig{
+		OmitEmpty: requiredfields.RequiredFieldsOmitEmpty{
+			Policy: requiredfields.RequiredFieldsOmitEmptyPolicyIgnore,
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	analysistest.RunWithSuggestedFixes(t, testdata, a, "omitempty_ignore")
+}

pkg/analysis/optionalfields/testdata/src/c/a.go.golden

@@ -0,0 +1,31 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package omitempty_ignore
+
+// TestOmitEmptyIgnore tests that when omitempty policy is set to Ignore,
+// no diagnostics are reported for required fields missing omitempty tags.
+type TestOmitEmptyIgnore struct {
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	// This field does not allow the zero value (empty string) and does not have omitempty.
+	// With Ignore policy, no diagnostic should be reported.
+	RequiredFieldWithoutOmitEmpty string `json:"requiredField"`
+
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	// This field has omitempty, so it should work normally.
+	RequiredFieldWithOmitEmpty string `json:"requiredFieldWithOmitEmpty,omitempty"`
+}

pkg/analysis/requiredfields/analyzer_test.go

@@ -176,15 +176,19 @@ func (s *serializationCheck) checkFieldPropertiesWithOmitEmptyRequired(pass *ana
 }
 
 func (s *serializationCheck) checkFieldPropertiesWithoutOmitEmpty(pass *analysis.Pass, field *ast.Field, fieldName string, jsonTags extractjsontags.FieldTagInfo, underlying ast.Expr, hasValidZeroValue, completeValidation, isPointer, isStruct bool, markersAccess markershelper.Markers, qualifiedFieldName string) {
+	// When policy is Ignore, skip all checks for fields without omitempty.
+	// We respect the user's choice to not enforce omitempty requirements.
+	if s.omitEmptyPolicy == OmitEmptyPolicyIgnore {
+		return
+	}
+
 	switch {
 	case hasValidZeroValue:
 		// The field is not omitempty, and the zero value is valid, the field does not need to be a pointer.
 		s.handleFieldShouldNotBePointer(pass, field, fieldName, isPointer, underlying, markersAccess, "field %s does not have omitempty and allows the zero value. The field does not need to be a pointer.", qualifiedFieldName)
 	case !hasValidZeroValue:
 		// The zero value would not be accepted, so the field needs to have omitempty.
-		// Force the omitempty policy to suggest a fix. We can only get to this function when the policy is configured to Ignore.
-		// Since we absolutely have to add the omitempty tag, we can report it as a suggestion.
-		reportShouldAddOmitEmpty(pass, field, OmitEmptyPolicySuggestFix, qualifiedFieldName, "field %s does not allow the zero value. It must have the omitempty tag.", jsonTags)
+		reportShouldAddOmitEmpty(pass, field, s.omitEmptyPolicy, qualifiedFieldName, "field %s does not allow the zero value. It must have the omitempty tag.", jsonTags)
 		// Once it has the omitempty tag, it will also need to be a pointer in some cases.
 		// Now handle it as if it had the omitempty already.
 		// We already handle the omitempty tag above, so force the `hasOmitEmpty` to true.

pkg/analysis/requiredfields/testdata/src/omitempty_ignore/test.go

@@ -10,7 +10,7 @@ type TestArrays struct {
 	ArrayWithOmitEmptyPtr []*string `json:"arrayWithOmitEmptyPtr,omitempty"`
 
 	// +kubebuilder:validation:MinItems=1
-	ArrayWithPositiveMinItems []string `json:"arrayWithPositiveMinItems"` // want "field TestArrays.ArrayWithPositiveMinItems does not allow the zero value. It must have the omitempty tag."
+	ArrayWithPositiveMinItems []string `json:"arrayWithPositiveMinItems"`
 
 	// +kubebuilder:validation:MinItems=1
 	ArrayWithPositiveMinItemsWithOmitEmpty []string `json:"arrayWithPositiveMinItemsWithOmitEmpty,omitempty"`
@@ -26,7 +26,7 @@ type TestArrays struct {
 	ByteArrayWithOmitEmpty []byte `json:"byteArrayWithOmitEmpty,omitempty"`
 
 	// +kubebuilder:validation:MinLength=1
-	ByteArrayWithMinLength []byte `json:"byteArrayWithMinLength"` // want "field TestArrays.ByteArrayWithMinLength does not allow the zero value. It must have the omitempty tag."
+	ByteArrayWithMinLength []byte `json:"byteArrayWithMinLength"`
 
 	// +kubebuilder:validation:MinLength=1
 	ByteArrayWithMinLengthWithOmitEmpty []byte `json:"byteArrayWithMinLengthWithOmitEmpty,omitempty"`
@@ -37,7 +37,7 @@ type TestArrays struct {
 	// +kubebuilder:validation:MinLength=0
 	ByteArrayWithMinLength0WithOmitEmpty []byte `json:"byteArrayWithMinLength0WithOmitEmpty,omitempty"`
 
-	PtrArray *[]string `json:"ptrArray"` // want "field TestArrays.PtrArray does not have omitempty and allows the zero value. The field does not need to be a pointer."
+	PtrArray *[]string `json:"ptrArray"`
 
 	PtrArrayWithOmitEmpty *[]string `json:"ptrArrayWithOmitEmpty,omitempty"` // want "field TestArrays.PtrArrayWithOmitEmpty underlying type does not need to be a pointer. The pointer should be removed."
 }

pkg/analysis/utils/serialization/serialization_check.go

@@ -10,7 +10,7 @@ type TestArrays struct {
 	ArrayWithOmitEmptyPtr []*string `json:"arrayWithOmitEmptyPtr,omitempty"`
 
 	// +kubebuilder:validation:MinItems=1
-	ArrayWithPositiveMinItems []string `json:"arrayWithPositiveMinItems,omitempty"` // want "field TestArrays.ArrayWithPositiveMinItems does not allow the zero value. It must have the omitempty tag."
+	ArrayWithPositiveMinItems []string `json:"arrayWithPositiveMinItems"`
 
 	// +kubebuilder:validation:MinItems=1
 	ArrayWithPositiveMinItemsWithOmitEmpty []string `json:"arrayWithPositiveMinItemsWithOmitEmpty,omitempty"`
@@ -26,7 +26,7 @@ type TestArrays struct {
 	ByteArrayWithOmitEmpty []byte `json:"byteArrayWithOmitEmpty,omitempty"`
 
 	// +kubebuilder:validation:MinLength=1
-	ByteArrayWithMinLength []byte `json:"byteArrayWithMinLength,omitempty"` // want "field TestArrays.ByteArrayWithMinLength does not allow the zero value. It must have the omitempty tag."
+	ByteArrayWithMinLength []byte `json:"byteArrayWithMinLength"`
 
 	// +kubebuilder:validation:MinLength=1
 	ByteArrayWithMinLengthWithOmitEmpty []byte `json:"byteArrayWithMinLengthWithOmitEmpty,omitempty"`
@@ -37,7 +37,7 @@ type TestArrays struct {
 	// +kubebuilder:validation:MinLength=0
 	ByteArrayWithMinLength0WithOmitEmpty []byte `json:"byteArrayWithMinLength0WithOmitEmpty,omitempty"`
 
-	PtrArray []string `json:"ptrArray"` // want "field TestArrays.PtrArray does not have omitempty and allows the zero value. The field does not need to be a pointer."
+	PtrArray *[]string `json:"ptrArray"`
 
-	PtrArrayWithOmitEmpty []string `json:"ptrArrayWithOmitEmpty,omitempty"` // want "field TestArrays.PtrArrayWithOmitEmpty underlying type does not need to be a pointer. The pointer should be removed."
+	PtrArrayWithOmitEmpty *[]string `json:"ptrArrayWithOmitEmpty,omitempty"` // want "field TestArrays.PtrArrayWithOmitEmpty underlying type does not need to be a pointer. The pointer should be removed."
 }

pkg/analysis/utils/serialization/testdata/src/pointers_when_required_omit_empty_ignore/arrays.go

@@ -5,7 +5,7 @@ type TestBools struct {
 
 	BoolWithOmitEmpty bool `json:"boolWithOmitEmpty,omitempty"` // want "field TestBools.BoolWithOmitEmpty has a valid zero value \\(false\\) and should be a pointer."
 
-	BoolPtr *bool `json:"boolPtr"` // want "field TestBools.BoolPtr does not have omitempty and allows the zero value. The field does not need to be a pointer."
+	BoolPtr *bool `json:"boolPtr"`
 
 	BoolPtrWithOmitEmpty *bool `json:"boolPtrWithOmitEmpty,omitempty"`
 }

pkg/analysis/utils/serialization/testdata/src/pointers_when_required_omit_empty_ignore/arrays.go.golden

@@ -3,9 +3,9 @@ package a
 type TestBools struct {
 	Bool bool `json:"bool"`
 
-	BoolWithOmitEmpty *bool `json:"boolWithOmitEmpty,omitempty"` // want "field TestBools.BoolWithOmitEmpty has a valid zero value \\(false\\) and should be a pointer."
+	BoolWithOmitEmpty bool `json:"boolWithOmitEmpty,omitempty"` // want "field TestBools.BoolWithOmitEmpty has a valid zero value \\(false\\) and should be a pointer."
 
-	BoolPtr bool `json:"boolPtr"` // want "field TestBools.BoolPtr does not have omitempty and allows the zero value. The field does not need to be a pointer."
+	BoolPtr *bool `json:"boolPtr"`
 
 	BoolPtrWithOmitEmpty *bool `json:"boolPtrWithOmitEmpty,omitempty"`
 }

pkg/analysis/utils/serialization/testdata/src/pointers_when_required_omit_empty_ignore/bool.go

@@ -5,12 +5,12 @@ type TestMaps struct {
 
 	MapWithOmitEmpty map[string]string `json:"mapWithOmitEmpty,omitempty"`
 
-	MapPtr *map[string]string `json:"mapPtr"` // want "field TestMaps.MapPtr does not have omitempty and allows the zero value. The field does not need to be a pointer."
+	MapPtr *map[string]string `json:"mapPtr"`
 
 	MapPtrWithOmitEmpty *map[string]string `json:"mapPtrWithOmitEmpty,omitempty"` // want "field TestMaps.MapPtrWithOmitEmpty underlying type does not need to be a pointer. The pointer should be removed."
 
 	// +kubebuilder:validation:MinProperties=1
-	MapWithPositiveMinProperties map[string]string `json:"mapWithPositiveMinProperties"` // want "field TestMaps.MapWithPositiveMinProperties does not allow the zero value. It must have the omitempty tag."
+	MapWithPositiveMinProperties map[string]string `json:"mapWithPositiveMinProperties"`
 
 	// +kubebuilder:validation:MinProperties=1
 	MapWithPositiveMinPropertiesWithOmitEmpty map[string]string `json:"mapWithPositiveMinPropertiesWithOmitEmpty,omitempty"`