Do not ignore *.yml file on linting while accepting *.yaml

From : https://github.com/helm/helm/pull/30712/files#r2417446037

Signed-off-by: Benoit Tigeot <benoit.tigeot@lifen.fr>

internal/chart/v3/lint/rules/template.go

@@ -126,7 +126,7 @@ func TemplatesWithSkipSchemaValidation(linter *support.Linter, values map[string
 		linter.RunLinterRule(support.ErrorSev, fpath, validateAllowedExtension(fileName))
 
 		// We only apply the following lint rules to yaml files
-		if filepath.Ext(fileName) != ".yaml" || filepath.Ext(fileName) == ".yml" {
+		if !isYamlFileExtension(fileName) {
 			continue
 		}
 
@@ -335,6 +335,11 @@ func validateListAnnotations(yamlStruct *k8sYamlStruct, manifest string) error {
 	return nil
 }
 
+func isYamlFileExtension(fileName string) bool {
+	ext := strings.ToLower(filepath.Ext(fileName))
+	return ext == ".yaml" || ext == ".yml"
+}
+
 // k8sYamlStruct stubs a Kubernetes YAML file.
 type k8sYamlStruct struct {
 	APIVersion string `json:"apiVersion"`

pkg/chart/v2/lint/rules/template.go

@@ -126,7 +126,7 @@ func TemplatesWithSkipSchemaValidation(linter *support.Linter, values map[string
 		linter.RunLinterRule(support.ErrorSev, fpath, validateAllowedExtension(fileName))
 
 		// We only apply the following lint rules to yaml files
-		if filepath.Ext(fileName) != ".yaml" || filepath.Ext(fileName) == ".yml" {
+		if !isYamlFileExtension(fileName) {
 			continue
 		}
 
@@ -335,6 +335,11 @@ func validateListAnnotations(yamlStruct *k8sYamlStruct, manifest string) error {
 	return nil
 }
 
+func isYamlFileExtension(fileName string) bool {
+	ext := strings.ToLower(filepath.Ext(fileName))
+	return ext == ".yaml" || ext == ".yml"
+}
+
 // k8sYamlStruct stubs a Kubernetes YAML file.
 type k8sYamlStruct struct {
 	APIVersion string `json:"apiVersion"`