refactor admission handler and add UT

Kubernetes-commit: ac7ca5bd0a3e5448a3d3ce89aeffa028f026b5ca

pkg/admission/BUILD

@@ -12,6 +12,7 @@ go_test(
         "chain_test.go",
         "config_test.go",
         "errors_test.go",
+        "handler_test.go",
     ],
     importpath = "k8s.io/apiserver/pkg/admission",
     library = ":go_default_library",

pkg/admission/handler.go

@@ -66,14 +66,8 @@ func (h *Handler) WaitForReady() bool {
 	if h.readyFunc == nil {
 		return true
 	}
-	return h.waitForReadyInternal(time.After(timeToWaitForReady))
-}
 
-func (h *Handler) waitForReadyInternal(timeout <-chan time.Time) bool {
-	// there is no configured ready func, so return immediately
-	if h.readyFunc == nil {
-		return true
-	}
+	timeout := time.After(timeToWaitForReady)
 	for !h.readyFunc() {
 		select {
 		case <-time.After(100 * time.Millisecond):

pkg/admission/handler_test.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2017 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 admission
+
+import (
+	"testing"
+	"time"
+)
+
+func TestWaitForReady(t *testing.T) {
+	handler := newFakeHandler()
+
+	// 1. test no readyFunc
+	if !handler.WaitForReady() {
+		t.Errorf("Expect ready for no readyFunc provided.")
+	}
+
+	// 2. readyFunc return ready immediately
+	readyFunc := func() bool {
+		return true
+	}
+	handler.SetReadyFunc(readyFunc)
+	if !handler.WaitForReady() {
+		t.Errorf("Expect ready for readyFunc returns ready immediately.")
+	}
+
+	// 3. readyFunc always return not ready. WaitForReady timeout
+	readyFunc = func() bool {
+		return false
+	}
+	startTime := time.Now()
+	handler.SetReadyFunc(readyFunc)
+	if handler.WaitForReady() {
+		t.Errorf("Expect not ready for readyFunc returns not ready immediately.")
+	}
+	if time.Since(startTime) < timeToWaitForReady {
+		t.Errorf("Expect WaitForReady timeout.")
+	}
+}
+
+func newFakeHandler() *Handler {
+	return NewHandler(Create, Update)
+}