测试是软件开发中重要的一步，本文介绍如何创建grpc的测试来保证代码的质量。这里都沿用的server和client代码

服务端测试

public class HelloWorldServerTest {  //定义服务名字用于绑定客户端调用的服务端  private static final String UNIQUE_SERVER_NAME = "in-process server for " + HelloWorldServerTest.class;  //创建一个进程内的server  private final Server inProcessServer = InProcessServerBuilder.forName(UNIQUE_SERVER_NAME).addService(new HelloServiceImpl()).directExecutor().build();  //创建一个进程内的channel  private final ManagedChannel inProcessChannel = InProcessChannelBuilder.forName(UNIQUE_SERVER_NAME).directExecutor().build();  /**   * 初始化进城内服务器   */  @Before  public void setUp() throws Exception {    inProcessServer.start();  }  /**   * 使用stub调用server并验证返回结果   */  @Test  public void testSimple() throws Exception {    HelloServiceGrpc.HelloServiceBlockingStub blockingStub = HelloServiceGrpc.newBlockingStub(inProcessChannel);    String testName = "World";    //调用服务    blog.proto.ProtoObj.Result reply = blockingStub.simpleHello(ProtoObj.Person.newBuilder().setMyName(testName).build());    //验证·    assertEquals("hello, " + testName, reply.getString());  }    /**   * 关闭服务器和channel   */  @After  public void tearDown() {    inProcessChannel.shutdownNow();    inProcessServer.shutdownNow();  }}

客户端测试

在客户端测试之前，需要对客户端进行一些改动，需要将channel变为实例变量，方便注入，这里以simple服务为例：

public class HelloClient {    private static final Logger logger = Logger.getLogger(HelloClient.class.getName());    //提出的channel    private final ManagedChannel channel;    //stub    private final HelloServiceGrpc.HelloServiceBlockingStub blockingStub;    //在构造方法中传入channel    public HelloClient(ManagedChannel channel){        this.channel=channel;        blockingStub = HelloServiceGrpc.newBlockingStub(channel);    }    public void simple(String name) {        logger.info("Will try to greet " + name + " ...");        ProtoObj.Person person = ProtoObj.Person.newBuilder().setMyName(name).build();        try {            ProtoObj.Result response = blockingStub.simpleHello(person);            logger.info(response.getString());        } catch (StatusRuntimeException e) {            logger.log(Level.WARNING, "RPC failed: {0}", e.getStatus());            return;        }    }}

之后进行测试：

public class HelloWorldClientTest {  //spy一个服务实例  private final HelloServiceGrpc.HelloServiceImplBase serviceImpl = spy(new HelloServiceGrpc.HelloServiceImplBase() {  });  private Server fakeServer;  private HelloClient client;  ManagedChannel channel;  /**   * 模拟server和channel并创建client   */  @Before  public void setUp() throws Exception {    String uniqueServerName = "fake server.java for " + getClass();    //创建进程内服务和channel    fakeServer = InProcessServerBuilder.forName(uniqueServerName).directExecutor().addService(serviceImpl).build().start();    InProcessChannelBuilder channelBuilder = InProcessChannelBuilder.forName(uniqueServerName).directExecutor();    channel=channelBuilder.build();    //创建client    client = new HelloClient(channel);  }  @Test  public void greet_messageDeliveredToServer() {    ArgumentCaptor< ProtoObj.Person> requestCaptor = ArgumentCaptor.forClass( ProtoObj.Person.class);    String testName = "world";    client.simple(testName);    //验证服务器期望收到的参数    verify(serviceImpl).simpleHello(requestCaptor.capture(), Matchers.
    
     
      >any());    assertEquals(testName, requestCaptor.getValue().getMyName());  }    @After  public void tearDown() throws Exception {    //关闭channel和server    channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);    fakeServer.shutdownNow();  }}
     
    

总结

在单元测试时一大麻烦的是多线程的处理，使用InProcessServerBuilder会创建进程内的调用，server和client将同步在main线程中调用，这样就减少了多线程、异步测试会遇到的问题。