NsdManager: add unit tests

This prepares some refactoring and the addition of a timeout to
resolveService.

Test: new tests pass
Bug: 37013369, 33298084
Change-Id: Ie8277bd5983278507bfa70495b4ce7d13895b24b

tests/net/java/android/net/nsd/NsdManagerTest.java

@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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 android.net.nsd;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.times;
+
+import android.os.HandlerThread;
+import android.os.Handler;
+import android.os.Looper;
+import android.content.Context;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import android.os.Message;
+import android.os.Messenger;
+import com.android.internal.util.AsyncChannel;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class NsdManagerTest {
+
+    @Mock Context mContext;
+    @Mock INsdManager mService;
+    MockServiceHandler mServiceHandler;
+
+    long mTimeoutMs = 100; // non-final so that tests can adjust the value.
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+
+        mServiceHandler = spy(MockServiceHandler.create(mContext));
+        when(mService.getMessenger()).thenReturn(new Messenger(mServiceHandler));
+    }
+
+    @Test
+    public void testResolveService() {
+        NsdManager manager = makeManager();
+
+        NsdServiceInfo request = new NsdServiceInfo("a_name", "a_type");
+        NsdServiceInfo reply = new NsdServiceInfo("resolved_name", "resolved_type");
+        NsdManager.ResolveListener listener = mock(NsdManager.ResolveListener.class);
+
+        manager.resolveService(request, listener);
+        int key1 = verifyRequest(NsdManager.RESOLVE_SERVICE);
+        int err = 33;
+        sendResponse(NsdManager.RESOLVE_SERVICE_FAILED, err, key1, null);
+        verify(listener, timeout(mTimeoutMs).times(1)).onResolveFailed(request, err);
+
+        manager.resolveService(request, listener);
+        int key2 = verifyRequest(NsdManager.RESOLVE_SERVICE);
+        sendResponse(NsdManager.RESOLVE_SERVICE_SUCCEEDED, 0, key2, reply);
+        verify(listener, timeout(mTimeoutMs).times(1)).onServiceResolved(reply);
+    }
+
+    @Test
+    public void testParallelResolveService() {
+        NsdManager manager = makeManager();
+
+        NsdServiceInfo request = new NsdServiceInfo("a_name", "a_type");
+        NsdServiceInfo reply = new NsdServiceInfo("resolved_name", "resolved_type");
+
+        NsdManager.ResolveListener listener1 = mock(NsdManager.ResolveListener.class);
+        NsdManager.ResolveListener listener2 = mock(NsdManager.ResolveListener.class);
+
+        manager.resolveService(request, listener1);
+        int key1 = verifyRequest(NsdManager.RESOLVE_SERVICE);
+
+        manager.resolveService(request, listener2);
+        int key2 = verifyRequest(NsdManager.RESOLVE_SERVICE);
+
+        sendResponse(NsdManager.RESOLVE_SERVICE_SUCCEEDED, 0, key2, reply);
+        sendResponse(NsdManager.RESOLVE_SERVICE_SUCCEEDED, 0, key1, reply);
+
+        verify(listener1, timeout(mTimeoutMs).times(1)).onServiceResolved(reply);
+        verify(listener2, timeout(mTimeoutMs).times(1)).onServiceResolved(reply);
+   }
+
+    NsdManager makeManager() {
+        NsdManager manager = new NsdManager(mContext, mService);
+        // Acknowledge first two messages connecting the AsyncChannel.
+        verify(mServiceHandler, timeout(mTimeoutMs).times(2)).handleMessage(any());
+        reset(mServiceHandler);
+        assertNotNull(mServiceHandler.chan);
+        return manager;
+    }
+
+    int verifyRequest(int expectedMessageType) {
+        verify(mServiceHandler, timeout(mTimeoutMs)).handleMessage(any());
+        reset(mServiceHandler);
+        Message received = mServiceHandler.lastMessage;
+        assertEquals(NsdManager.nameOf(expectedMessageType), NsdManager.nameOf(received.what));
+        return received.arg2;
+    }
+
+    void sendResponse(int replyType, int arg, int key, Object obj) {
+        mServiceHandler.chan.sendMessage(replyType, arg, key, obj);
+    }
+
+    // Implements the server side of AsyncChannel connection protocol
+    public static class MockServiceHandler extends Handler {
+        public Context mContext;
+        public AsyncChannel chan;
+        public Message lastMessage;
+
+        MockServiceHandler(Looper looper, Context context) {
+            super(looper);
+            mContext = context;
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            lastMessage = obtainMessage();
+            lastMessage.copyFrom(msg);
+            if (msg.what == AsyncChannel.CMD_CHANNEL_FULL_CONNECTION) {
+                chan = new AsyncChannel();
+                chan.connect(mContext, this, msg.replyTo);
+                chan.sendMessage(AsyncChannel.CMD_CHANNEL_FULLY_CONNECTED);
+            }
+
+        }
+
+        public static MockServiceHandler create(Context context) {
+            HandlerThread t = new HandlerThread("mock-service-handler");
+            t.start();
+            return new MockServiceHandler(t.getLooper(), context);
+        }
+    }
+}