add validation and test case

kustomize/commands/edit/add/addmetadata.go

@@ -116,6 +116,9 @@ func (o *addMetadataOptions) validateAndParse(args []string) error {
 	if len(args) < 1 {
 		return fmt.Errorf("must specify %s", o.kind)
 	}
+	if !o.labelsWithoutSelector && o.includeTemplates {
+		return fmt.Errorf("--without-selector flag must be specified for --include-templates to work")
+	}
 	m, err := util.ConvertSliceToMap(args, o.kind.String())
 	if err != nil {
 		return err

kustomize/commands/edit/add/addmetadata_test.go

@@ -294,6 +294,19 @@ func TestAddLabelWithoutSelectorIncludeTemplates(t *testing.T) {
 	assert.Equal(t, m.Labels[0], types.Label{Pairs: map[string]string{"new": "label"}, IncludeTemplates: true})
 }
 
+func TestAddLabelIncludeTemplatesWithoutRequiredFlag(t *testing.T) {
+	fSys := filesys.MakeFsInMemory()
+	v := valtest_test.MakeHappyMapValidator(t)
+	cmd := newCmdAddLabel(fSys, v.Validator)
+	args := []string{"new:label"}
+	_ = cmd.Flag("include-templates").Value.Set("true")
+	_ = cmd.Flag("without-selector").Value.Set("false")
+	err := cmd.RunE(cmd, args)
+	v.VerifyNoCall()
+	require.Error(t, err)
+	require.Containsf(t, err.Error(), "--without-selector flag must be specified for --include-templates to work", "incorrect error: %s", err.Error())
+}
+
 func TestAddLabelWithoutSelectorAddLabel(t *testing.T) {
 	var o addMetadataOptions
 	o.metadata = map[string]string{"owls": "cute", "otters": "adorable"}