Add SafePtr wrapper

Author: kaisoz

safeptr.go

@@ -0,0 +1,34 @@
+//go:build go1.18
+// +build go1.18
+
+/*
+Copyright 2023 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 klog
+
+// SafePtr is a function that takes a pointer of any type (T) as an argument.
+// If the provided pointer is not nil, it returns the same pointer. If it is nil, it returns nil instead.
+//
+// This function is particularly useful to prevent nil pointer dereferencing when:
+//
+// - The type implements interfaces that are called by the logger, such as `fmt.Stringer`.
+// - And these interface implementations do not perform nil checks themselves.
+func SafePtr[T any](p *T) any {
+if p == nil {
+return nil
+}
+return p
+}

safeptr_test.go

@@ -0,0 +1,41 @@
+//go:build go1.18
+// +build go1.18
+
+/*
+Copyright 2023 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 klog_test
+
+import (
+"testing"
+
+"k8s.io/klog/v2"
+)
+
+func TestSafePtr(t *testing.T) {
+// Test with nil pointer
+var stringPtr *string = nil
+if result := klog.SafePtr(stringPtr); result != nil {
+t.Errorf("Expected nil, got %p", result)
+}
+
+// Test with non-nil pointer
+expected := "foo"
+stringPtr = &expected
+if result := klog.SafePtr(stringPtr); result != stringPtr {
+t.Errorf("Expected %v, got %v", stringPtr, result)
+}
+}