使用Android排球进行单元测试

Question

我想知道如何为排球框架创建单元测试.模拟请求,响应,以便我可以创建不需要Web服务工作和网络访问的单元测试.

我用谷歌搜索了它,但我根本找不到有关该框架的更多信息

Answer 1

我实现了一个名为FakeHttpStack的HttpStack子类,它从res/raw中的本地文件加载伪响应体.我这样做是为了开发目的,也就是说,我可以在服务器准备好之前为新API开发一些东西,但是你可以从这里学到一些东西(例如,重写HttpStack#peformRequest和createEntity).

/**
 * Fake {@link HttpStack} that returns the fake content using resource file in res/raw.
 */
class FakeHttpStack implements HttpStack {
    private static final String DEFAULT_STRING_RESPONSE = "Hello";
    private static final String DEFAULT_JSON_RESPONSE = " {\"a\":1,\"b\":2,\"c\":3}";
    private static final String URL_PREFIX = "http://example.com/";
    private static final String LOGGER_TAG = "STACK_OVER_FLOW";

    private static final int SIMULATED_DELAY_MS = 500;
    private final Context context;

    FakeHttpStack(Context context) {
        this.context = context;
    }

    @Override
    public HttpResponse performRequest(Request<?> request, Map<String, String> stringStringMap)
            throws IOException, AuthFailureError {
        try {
            Thread.sleep(SIMULATED_DELAY_MS);
        } catch (InterruptedException e) {
        }
        HttpResponse response
                = new BasicHttpResponse(new BasicStatusLine(HttpVersion.HTTP_1_1, 200, "OK"));
        List<Header> headers = defaultHeaders();
        response.setHeaders(headers.toArray(new Header[0]));
        response.setLocale(Locale.JAPAN);
        response.setEntity(createEntity(request));
        return response;
    }

    private List<Header> defaultHeaders() {
        DateFormat dateFormat = new SimpleDateFormat("EEE, dd mmm yyyy HH:mm:ss zzz");
        return Lists.<Header>newArrayList(
                new BasicHeader("Date", dateFormat.format(new Date())),
                new BasicHeader("Server",
                        /* Data below is header info of my server */
                        "Apache/1.3.42 (Unix) mod_ssl/2.8.31 OpenSSL/0.9.8e")
        );
    }

    /**
     * returns the fake content using resource file in res/raw. fake_res_foo.txt is used for
     * request to http://example.com/foo
     */
    private HttpEntity createEntity(Request request) throws UnsupportedEncodingException {
        String resourceName = constructFakeResponseFileName(request);
        int resourceId = context.getResources().getIdentifier(
                resourceName, "raw", context.getApplicationContext().getPackageName());
        if (resourceId == 0) {
            Log.w(LOGGER_TAG, "No fake file named " + resourceName
                    + " found. default fake response should be used.");
        } else {
            InputStream stream = context.getResources().openRawResource(resourceId);
            try {
                String string = CharStreams.toString(new InputStreamReader(stream, Charsets.UTF_8));
                return new StringEntity(string);
            } catch (IOException e) {
                Log.e(LOGGER_TAG, "error reading " + resourceName, e);
            }
        }

        // Return default value since no fake file exists for given URL.
        if (request instanceof StringRequest) {
            return new StringEntity(DEFAULT_STRING_RESPONSE);
        }
        return new StringEntity(DEFAULT_JSON_RESPONSE);
    }

    /**
     * Map request URL to fake file name
     */
    private String constructFakeResponseFileName(Request request) {
        String reqUrl = request.getUrl();
        String apiName = reqUrl.substring(URL_PREFIX.length());
        return "fake_res_" + apiName;
    }
}

要使用FakeHttpStack,您只需将其传递给RequestQueue即可.我也覆盖了RequestQueue.

public class FakeRequestQueue extends RequestQueue {
    public FakeRequestQueue(Context context) {
        super(new NoCache(), new BasicNetwork(new FakeHttpStack(context)));
    }
}

这种方法的好处在于,它不需要对代码进行太多更改.您只需在测试时将RequestQueue切换到FakeRequestQueue.因此,它可以用于验收测试或系统测试.

另一方面,对于单元测试,可能会有更紧凑的方式.例如,您可以将Request.Listener子类实现为单独的类,以便可以轻松地测试onResponse方法.我建议你详细说明你想要测试的内容或者放一些代码片段.

Answer 2

看一下volley tests文件夹,你可以在那里找到例子.

MockCache.java
MockHttpClient.java
MockHttpStack.java
MockHttpURLConnection.java
MockNetwork.java
MockRequest.java
MockResponseDelivery.java

Answer 3

不能 100% 确定我明白你想要做什么，但如果我明白，那么 easymock （一个允许创建模拟类的库，你可以调用并接收预定的响应）将为你提供很多帮助。一个叫 Lars Vogel 的人写了一篇关于这个主题的好文章，我不久前使用它时发现它很有用。

http://www.vogella.com/articles/EasyMock/article.html