From 22d015afc1067f8895a2603ae859d11d33f06a36 Mon Sep 17 00:00:00 2001
From: Andrei Scripniciuc
 <46186670+andrei-scripniciuc@users.noreply.github.com>
Date: Fri, 12 Apr 2024 10:27:18 -0700
Subject: [PATCH] feat(AIP-133): ignore create methods with invalid LRO
 response types (#1366)

* feat(AIP-133): ignore create methods with invalid LRO response types

* chore: clean up return type resolution logic
---
 rules/aip0133/request_required_fields.go |  2 +-
 rules/internal/utils/method.go           | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/rules/aip0133/request_required_fields.go b/rules/aip0133/request_required_fields.go
index 6ba022947..04111a3dd 100644
--- a/rules/aip0133/request_required_fields.go
+++ b/rules/aip0133/request_required_fields.go
@@ -28,7 +28,7 @@ import (
 // The create request message should not have unrecognized fields.
 var requestRequiredFields = &lint.MethodRule{
 	Name:   lint.NewRuleName(133, "request-required-fields"),
-	OnlyIf: utils.IsCreateMethod,
+	OnlyIf: utils.IsCreateMethodWithResolvedReturnType,
 	LintMethod: func(m *desc.MethodDescriptor) []lint.Problem {
 		ot := utils.GetResponseType(m)
 		r := utils.GetResource(ot)
diff --git a/rules/internal/utils/method.go b/rules/internal/utils/method.go
index 3de11d923..69f2ad62d 100644
--- a/rules/internal/utils/method.go
+++ b/rules/internal/utils/method.go
@@ -36,6 +36,18 @@ func IsCreateMethod(m *desc.MethodDescriptor) bool {
 	return createMethodRegexp.MatchString(m.GetName())
 }
 
+// IsCreateMethod returns true if this is a AIP-133 Create method with
+// a non-nil response type. This method should be used for filtering in linter
+// rules which access the response type of the method, to avoid crashing due
+// to dereferencing a nil pointer to the response.
+func IsCreateMethodWithResolvedReturnType(m *desc.MethodDescriptor) bool {
+	if !IsCreateMethod(m) {
+		return false
+	}
+
+	return GetResponseType(m) != nil
+}
+
 // IsGetMethod returns true if this is a AIP-131 Get method.
 func IsGetMethod(m *desc.MethodDescriptor) bool {
 	methodName := m.GetName()