NsdManager: add unit tests

import java.util.concurrent.CountDownLatch;

import com.android.internal.annotations.VisibleForTesting;

import com.android.internal.util.AsyncChannel;

import com.android.internal.util.Protocol;

        public void onServiceResolved(NsdServiceInfo serviceInfo);

    }

    private class ServiceHandler extends Handler {

    @VisibleForTesting

    class ServiceHandler extends Handler {

        ServiceHandler(Looper looper) {

            super(looper);

        }

/*

 * 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);

        }

    }

}