fix: Do not require undelete method if delete is not present. (#753)

rules/aip0164/declarative_friendly_required.go

@@ -20,7 +20,8 @@ var declarativeFriendlyRequired = &lint.MessageRule{
 	LintMessage: func(m *desc.MessageDescriptor) []lint.Problem {
 		resource := m.GetName()
 		want := fmt.Sprintf("Undelete%s", resource)
-		if utils.FindMethod(m.GetFile(), want) == nil {
+		delete := fmt.Sprintf("Delete%s", resource)
+		if utils.FindMethod(m.GetFile(), want) == nil && utils.FindMethod(m.GetFile(), delete) != nil {
 			return []lint.Problem{{
 				Message:    fmt.Sprintf("Declarative-friendly %s should have an Undelete method.", resource),
 				Descriptor: m,

rules/aip0164/declarative_friendly_required_test.go

@@ -20,15 +20,18 @@ func TestDeclarativeFriendlyRequired(t *testing.T) {
 		t.Run(test.testName, func(t *testing.T) {
 			file := testutils.ParseProto3Tmpl(t, `
 				import "google/api/resource.proto";
+				import "google/protobuf/empty.proto";
 				service Library {
 					rpc {{.MethodName}}({{.MethodName}}Request) returns (Book);
+					rpc DeleteBook(DeleteBookRequest) returns (google.protobuf.Empty);
 				}
 				message Book {
 					option (google.api.resource) = {
 						{{.Style}}
 					};
 				}
 				message {{.MethodName}}Request {}
+				message DeleteBookRequest {}
 			`, test)
 			message := file.GetMessageTypes()[0]
 			problems := declarativeFriendlyRequired.Lint(file)
@@ -37,4 +40,24 @@ func TestDeclarativeFriendlyRequired(t *testing.T) {
 			}
 		})
 	}
+
+	// Also test that undelete is not required if delete is not present.
+	t.Run("ValidNoDelete", func(t *testing.T) {
+		file := testutils.ParseProto3String(t, `
+			import "google/api/resource.proto";
+			service Library {
+				rpc GetBook(GetBookRequest) returns (Book);
+			}
+			message Book {
+				option (google.api.resource) = {
+					style: DECLARATIVE_FRIENDLY
+				};
+			}
+			message GetBookRequest {}
+		`)
+		problems := declarativeFriendlyRequired.Lint(file)
+		if len(problems) > 0 {
+			t.Errorf("Got %v, expected no problems.", problems)
+		}
+	})
 }