add FieldName API

pkg/analysis/commentstart/analyzer.go

@@ -27,6 +27,7 @@ import (
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/inspector"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/markers"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 )
 
 const name = "commentstart"
@@ -58,10 +59,8 @@ func checkField(pass *analysis.Pass, field *ast.Field, tagInfo extractjsontags.F
 		return
 	}
 
-	var fieldName string
-	if len(field.Names) > 0 {
-		fieldName = field.Names[0].Name
-	} else {
+	fieldName := utils.FieldName(field)
+	if fieldName == "" {
 		fieldName = types.ExprString(field.Type)
 	}
 

pkg/analysis/helpers/inspector/analyzer_test.go

@@ -25,6 +25,7 @@ import (
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/inspector"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/markers"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 )
 
 func TestInspector(t *testing.T) {
@@ -49,14 +50,7 @@ func run(pass *analysis.Pass) (any, error) {
 	}
 
 	inspect.InspectFields(func(field *ast.Field, stack []ast.Node, jsonTagInfo extractjsontags.FieldTagInfo, markersAccess markers.Markers) {
-		var fieldName string
-		if len(field.Names) > 0 {
-			fieldName = field.Names[0].Name
-		} else if ident, ok := field.Type.(*ast.Ident); ok {
-			fieldName = ident.Name
-		}
-
-		pass.Reportf(field.Pos(), "field: %v", fieldName)
+		pass.Reportf(field.Pos(), "field: %v", utils.FieldName(field))
 
 		if jsonTagInfo.Name != "" {
 			pass.Reportf(field.Pos(), "json tag: %v", jsonTagInfo.Name)

pkg/analysis/jsontags/analyzer.go

@@ -24,6 +24,7 @@ import (
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/inspector"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/markers"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 	"sigs.k8s.io/kube-api-linter/pkg/config"
 
 	"golang.org/x/tools/go/analysis"
@@ -75,13 +76,13 @@ func (a *analyzer) run(pass *analysis.Pass) (any, error) {
 }
 
 func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field, tagInfo extractjsontags.FieldTagInfo) {
-	var prefix string
-	if len(field.Names) > 0 && field.Names[0] != nil {
-		prefix = fmt.Sprintf("field %s", field.Names[0].Name)
-	} else if ident, ok := field.Type.(*ast.Ident); ok {
-		prefix = fmt.Sprintf("embedded field %s", ident.Name)
+	prefix := "field %s"
+	if len(field.Names) == 0 || field.Names[0] == nil {
+		prefix = "embedded field %s"
 	}
 
+	prefix = fmt.Sprintf(prefix, utils.FieldName(field))
+
 	if tagInfo.Missing {
 		pass.Reportf(field.Pos(), "%s is missing json tag", prefix)
 		return

pkg/analysis/maxlength/analyzer.go

@@ -55,11 +55,11 @@ func run(pass *analysis.Pass) (any, error) {
 }
 
 func checkField(pass *analysis.Pass, field *ast.Field, markersAccess markershelper.Markers) {
-	if len(field.Names) == 0 || field.Names[0] == nil {
+	fieldName := utils.FieldName(field)
+	if fieldName == "" {
 		return
 	}
 
-	fieldName := field.Names[0].Name
 	prefix := fmt.Sprintf("field %s", fieldName)
 
 	checkTypeExpr(pass, field.Type, field, nil, markersAccess, prefix, markers.KubebuilderMaxLengthMarker, needsStringMaxLength)

pkg/analysis/nomaps/analyzer.go

@@ -26,6 +26,7 @@ import (
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/inspector"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/markers"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 	"sigs.k8s.io/kube-api-linter/pkg/config"
 )
 
@@ -81,7 +82,7 @@ func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field) {
 	}
 
 	if a.policy == config.NoMapsEnforce {
-		report(pass, field.Pos(), field.Names[0].Name)
+		report(pass, field.Pos(), utils.FieldName(field))
 		return
 	}
 
@@ -90,7 +91,7 @@ func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field) {
 			return
 		}
 
-		report(pass, field.Pos(), field.Names[0].Name)
+		report(pass, field.Pos(), utils.FieldName(field))
 	}
 
 	if a.policy == config.NoMapsIgnore {
@@ -104,7 +105,7 @@ func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field) {
 			return
 		}
 
-		report(pass, field.Pos(), field.Names[0].Name)
+		report(pass, field.Pos(), utils.FieldName(field))
 	}
 }
 

pkg/analysis/nophase/analyzer.go

@@ -24,6 +24,7 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 	kalerrors "sigs.k8s.io/kube-api-linter/pkg/analysis/errors"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 )
 
 const name = "nophase"
@@ -68,7 +69,7 @@ func run(pass *analysis.Pass) (any, error) {
 			return
 		}
 
-		fieldName := field.Names[0].Name
+		fieldName := utils.FieldName(field)
 
 		// First check if the struct field name contains 'phase'
 		if strings.Contains(strings.ToLower(fieldName), "phase") {

pkg/analysis/optionalorrequired/analyzer.go

@@ -24,6 +24,7 @@ import (
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/inspector"
 	markershelper "sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/markers"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 	"sigs.k8s.io/kube-api-linter/pkg/config"
 	"sigs.k8s.io/kube-api-linter/pkg/markers"
 )
@@ -107,13 +108,13 @@ func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field, fieldMarker
 		return
 	}
 
-	var prefix string
-	if len(field.Names) > 0 && field.Names[0] != nil {
-		prefix = fmt.Sprintf("field %s", field.Names[0].Name)
-	} else if ident, ok := field.Type.(*ast.Ident); ok {
-		prefix = fmt.Sprintf("embedded field %s", ident.Name)
+	prefix := "field %s"
+	if len(field.Names) == 0 || field.Names[0] == nil {
+		prefix = "embedded field %s"
 	}
 
+	prefix = fmt.Sprintf(prefix, utils.FieldName(field))
+
 	hasPrimaryOptional := fieldMarkers.Has(a.primaryOptionalMarker)
 	hasPrimaryRequired := fieldMarkers.Has(a.primaryRequiredMarker)
 

pkg/analysis/requiredfields/analyzer.go

@@ -25,6 +25,7 @@ import (
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/extractjsontags"
 	"sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/inspector"
 	markershelper "sigs.k8s.io/kube-api-linter/pkg/analysis/helpers/markers"
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
 	"sigs.k8s.io/kube-api-linter/pkg/config"
 	"sigs.k8s.io/kube-api-linter/pkg/markers"
 )
@@ -71,12 +72,11 @@ func (a *analyzer) run(pass *analysis.Pass) (any, error) {
 }
 
 func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field, fieldMarkers markershelper.MarkerSet, fieldTagInfo extractjsontags.FieldTagInfo) {
-	if field == nil || len(field.Names) == 0 {
+	fieldName := utils.FieldName(field)
+	if fieldName == "" {
 		return
 	}
 
-	fieldName := field.Names[0].Name
-
 	if !fieldMarkers.Has(markers.RequiredMarker) && !fieldMarkers.Has(markers.KubebuilderRequiredMarker) {
 		// The field is not marked required, so we don't need to check it.
 		return

pkg/analysis/utils/type_check.go

@@ -62,11 +62,11 @@ func (t *typeChecker) CheckNode(pass *analysis.Pass, node ast.Node) {
 }
 
 func (t *typeChecker) checkField(pass *analysis.Pass, field *ast.Field) {
-	if field == nil || len(field.Names) == 0 || field.Names[0] == nil {
+	fieldName := FieldName(field)
+	if fieldName == "" {
 		return
 	}
 
-	fieldName := field.Names[0].Name
 	prefix := fmt.Sprintf("field %s", fieldName)
 
 	t.checkTypeExpr(pass, field.Type, field, prefix)

pkg/analysis/utils/utils.go

@@ -77,6 +77,26 @@ func LookupTypeSpec(pass *analysis.Pass, ident *ast.Ident) (*ast.TypeSpec, bool)
 	return nil, false
 }
 
+// FieldName returns the name of the field. If the field has a name, it returns that name.
+// If the field is embedded and it can be converted to an identifier, it returns the name of the identifier.
+// If it doesn't have a name and can't be converted to an identifier, it returns an empty string.
+func FieldName(field *ast.Field) string {
+	if len(field.Names) > 0 && field.Names[0] != nil {
+		return field.Names[0].Name
+	}
+
+	switch typ := field.Type.(type) {
+	case *ast.Ident:
+		return typ.Name
+	case *ast.StarExpr:
+		if ident, ok := typ.X.(*ast.Ident); ok {
+			return ident.Name
+		}
+	}
+
+	return ""
+}
+
 func getFilesForType(pass *analysis.Pass, ident *ast.Ident) (*token.File, *ast.File) {
 	namedType, ok := pass.TypesInfo.TypeOf(ident).(*types.Named)
 	if !ok {

pkg/analysis/utils/utils_suite_test.go

@@ -0,0 +1,28 @@
+/*
+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 utils_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestValidation(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Utils")
+}

pkg/analysis/utils/utils_test.go

@@ -0,0 +1,75 @@
+/*
+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 utils_test
+
+import (
+	"go/ast"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"sigs.k8s.io/kube-api-linter/pkg/analysis/utils"
+)
+
+var _ = Describe("FieldName", func() {
+	type fieldNameInput struct {
+		field *ast.Field
+		want  string
+	}
+
+	DescribeTable("Should extract the field name", func(in fieldNameInput) {
+		Expect(utils.FieldName(in.field)).To(Equal(in.want), "expect to match the extracted field name")
+	},
+		Entry("field has Names", fieldNameInput{
+			field: &ast.Field{
+				Names: []*ast.Ident{
+					{
+						Name: "foo",
+					},
+				},
+			},
+			want: "foo",
+		}),
+		Entry("field has no Names, but is an Ident", fieldNameInput{
+			field: &ast.Field{
+				Type: &ast.Ident{
+					Name: "foo",
+				},
+			},
+			want: "foo",
+		}),
+		Entry("field has no Names, but is a StarExpr with an Ident", fieldNameInput{
+			field: &ast.Field{
+				Type: &ast.StarExpr{
+					X: &ast.Ident{
+						Name: "foo",
+					},
+				},
+			},
+			want: "foo",
+		}),
+		Entry("field has no Names, and is not an Ident or StarExpr", fieldNameInput{
+			field: &ast.Field{
+				Type: &ast.ArrayType{
+					Elt: &ast.Ident{
+						Name: "foo",
+					},
+				},
+			},
+			want: "",
+		}),
+	)
+})