Add documentation to force build

Author: rytswd

pkg/testutil/doc.go

@@ -0,0 +1,22 @@
+// Package testutil provides test utility for Kubernetes operators. The amin
+// support is around envtest and resource watching logic, where you can use
+// the following code to wait for the matching resource to appear.
+//
+// Example:
+//
+//	watcher.SetCmpOpts(testutil.CompareSpecOnly()...)
+//	expectedSts := &appsv1.StatefulSet{
+//	    Spec: appsv1.StatefulSetSpec{Replicas: ptr.To(int32(3))},
+//	}
+//	expectedSvc := &corev1.Service{...}
+//
+//	err := watcher.WaitForMatch(expectedSts, expectedSvc)
+//	if err != nil {
+//	    t.Errorf("Resources never reached expected state: %v", err)
+//	}
+//
+// This utility allows resource matching logic to be fully declarative, and
+// while integration tests are more expensive to run in terms of time spent,
+// this makes sure that there is no unnecessary sleep logic, and all the tests
+// can be run in an event driven fashion.
+package testutil