如何对http请求进行单元测试

Question

我使用了库Robolectric，这是另一个可能的框架。用于Android http://loopj.com/android-async-http/的Http客户机

static AsyncHttpClient client = new AsyncHttpClient();

public static void getData (final ServerCallback callback) {

    client.get("http://httpbin.org/get", new AsyncHttpResponseHandler() {

        @Override
        public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
            callback.onSuccess(statusCode, new String(responseBody));
        }

        @Override
        public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
            callback.onFailure(statusCode, new String(responseBody));
        }

    });
}

试题班：

@RunWith(RobolectricTestRunner.class)
public class ApiTest{

@Test
public void testgetData () {

}

}

接口

public interface ServerCallback {
    // Api detect connection
    void onSuccess(int statusCode, String response);
    void onFailure(int statusCode, String response);
}

Answer 1

Роман，

我会给出一个大致的答案，让你走上正确的方向。测试http请求的首选方法是使用square okhttp mockwebserver。如果您对项目单元测试的使用有疑问，请检查它们。

在您的具体案例中，有几个问题需要解决：

• 您需要覆盖测试中使用的基url
• 但是，为了运行一致的单元测试，android-async-http库是异步的，您希望请求/响应是同步的

因此，按照您的示例，让我们按照以下步骤设置您的测试客户机：

public class TestHttpClient {
    // package-local client that can be set in tests
    static AsyncHttpClient client = new AsyncHttpClient(); 
    // package-local baseUrl that can be set in tests
    static String baseUrl = "http://pastbin.org/";  

    public static void getData(final ServerCallback callback) {
        String url = baseUrl + "get";
        client.get(url, new AsyncHttpResponseHandler() {
            @Override
            public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
                callback.onSuccess(statusCode, new String(responseBody));
            }

            @Override
            public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
                callback.onFailure(statusCode, new String(responseBody));
            }
        });
    }
}

若要测试TestHttpClient，请使用MockWebServer为测试拆分服务器，并设置客户端向服务器发出请求：

@RunWith(RobolectricTestRunner.class)
@Config(manifest = Config.NONE, sdk = Build.VERSION_CODES.LOLLIPOP)
public class TestHttpRequestTest {

    @Rule
    public MockWebServer mockWebServer = new MockWebServer();

    @Test
    public void getData_onSuccess_doesSomething() throws InterruptedException {
        // Here we are creating a mock ServerCallback.  We will use
        // this mock object to verify the callback is invoked
        ServerCallback callback = mock(ServerCallback.class);

        // To test the client, we need to send a request to the mock mockWebServer.
        // The MockWebServer spins up an actual backend to handle calls.  You MUST
        // setup the client to use the base Url of the mockWebServer instead of
        // the actual url e.g.: http://httpbin.org.
        TestHttpClient.baseUrl = mockWebServer.url("/").toString();

        // For testing, use a synchronous client so that we can get the response before
        // the test completes.
        TestHttpClient.client = new SyncHttpClient();

        // Set up the mockWebServer to return a MockResponse with
        // some data in the body. This data can be whatever you want... json, xml, etc.
        // The default response code is 200.
        mockWebServer.enqueue(new MockResponse().setBody("success"));
        // To simulate an error
        // mockWebServer.enqueue(new MockResponse().setResponseCode(500).setBody("error"));

        TestHttpClient.getData(callback); // calling the method under test

        verify(callback).onSuccess(200, "success"); // using verify of mockito
    }
}

备注：

• async http client库需要一些android系统组件才能正常工作，因此必须使用@RunWith(...)注释。
• MockWebServer需要将sdk设置为v21或更高版本的@Config(sdk = 21)来使用v21。

要在项目中包括mockwebserver & mockito，请将以下内容添加到build.gradle中

dependencies {
        testCompile 'com.squareup.okhttp3:mockwebserver:3.2.0'
        testCompile 'org.mockito:mockito-core:1.10.19'
    }

考试愉快！