fix access request cache test race (#44652)

lib/services/access_request_cache.go

@@ -344,6 +344,7 @@ func (c *AccessRequestCache) getResourcesAndUpdateCurrent(ctx context.Context) e
 	c.rw.Lock()
 	defer c.rw.Unlock()
 	c.primaryCache = cache
+	close(c.initC)
 	return nil
 }
 
@@ -394,6 +395,12 @@ func (c *AccessRequestCache) initializationChan() <-chan struct{} {
 	return c.initC
 }
 
+// InitializationChan is part of the resourceCollector interface and gets the channel
+// used to signal that the accessRequestCache has been initialized.
+func (c *AccessRequestCache) InitializationChan() <-chan struct{} {
+	return c.initializationChan()
+}
+
 // Close terminates the background process that keeps the access request cache up to
 // date, and terminates any inflight load operations.
 func (c *AccessRequestCache) Close() error {

lib/services/access_request_cache_test.go

@@ -51,6 +51,12 @@ func newAccessRequestPack(t *testing.T) (accessRequestServices, *services.Access
 	})
 	require.NoError(t, err)
 
+	select {
+	case <-cache.InitializationChan():
+	case <-time.After(time.Second * 30):
+		require.FailNow(t, "timeout waiting for access request cache to initialize")
+	}
+
 	return svcs, cache
 }