Ensure caches are synchronized in reconciler tests (#3734)

Caches are started asynchronously, and we should wait for them to be
synchronized before proceeding with the test logic. In real execution,
controller-runtime takes care of this for us, but in tests which only
use the reconciler, we need to do it ourselves.

Author: swiatekm

controllers/reconcile_test.go

@@ -1362,7 +1362,7 @@ func createTestReconciler(t *testing.T, ctx context.Context, cfg config.Config)
 	require.NoError(t, err)
 	go func() {
 		startErr := runtimeCluster.Start(ctx)
-		require.NoError(t, startErr)
+		assert.NoError(t, startErr)
 	}()
 
 	cacheClient := runtimeCluster.GetClient()
@@ -1375,6 +1375,8 @@ func createTestReconciler(t *testing.T, ctx context.Context, cfg config.Config)
 	})
 	err = reconciler.SetupCaches(runtimeCluster)
 	require.NoError(t, err)
+	synced := runtimeCluster.GetCache().WaitForCacheSync(ctx)
+	require.True(t, synced, "caches didn't sync successfully")
 	return reconciler
 }