我正在尝试使用 Espresso 来测试我的 UI。当我登录到我的应用程序时，我调用 Parse API(网络调用)来验证用户名和密码。如果一切顺利，用户将被引导至新 Activity 。我想对此进行测试，但我似乎无法使用空闲资源。

代码:

public class ApplicationTest extends ActivityInstrumentationTestCase2<LoginActivity> {


private CountingIdlingResource fooServerIdlingResource;

public ApplicationTest() {
    super(LoginActivity.class);
}

@Before
public void setUp() throws Exception {
    super.setUp();
    injectInstrumentation(InstrumentationRegistry.getInstrumentation());
    getActivity();
    CountingIdlingResource countingResource = new CountingIdlingResource("FooServerCalls");
    this.fooServerIdlingResource = countingResource;
    Espresso.registerIdlingResources(countingResource);
}


public void testChangeText_sameActivity() {
    // Type text and then press the button.
    onView(withId(R.id.username))
            .perform(typeText("s@s.nl"), closeSoftKeyboard());
    onView(withId(R.id.password))
            .perform(typeText("s"), closeSoftKeyboard());

    if(performClick())
        onView(withId(R.id.main_relative_layout))
                .check(matches(isDisplayed()));
    // Check that the text was changed.
}

public boolean performClick(){
    fooServerIdlingResource.increment();
    try {
        onView(withId(R.id.login)).perform(click());
        return true;
    } finally {
        fooServerIdlingResource.decrement();
    }
}


@SuppressWarnings("javadoc")
public final class CountingIdlingResource implements IdlingResource {
    private static final String TAG = "CountingIdlingResource";
    private final String resourceName;
    private final AtomicInteger counter = new AtomicInteger(0);
    private final boolean debugCounting;

    // written from main thread, read from any thread.
    private volatile ResourceCallback resourceCallback;

    // read/written from any thread - used for debugging messages.
    private volatile long becameBusyAt = 0;
    private volatile long becameIdleAt = 0;

    /**
     * Creates a CountingIdlingResource without debug tracing.
     *
     * @param resourceName the resource name this resource should report to Espresso.
     */
    public CountingIdlingResource(String resourceName) {
        this(resourceName, false);
    }

    /**
     * Creates a CountingIdlingResource.
     *
     * @param resourceName  the resource name this resource should report to Espresso.
     * @param debugCounting if true increment & decrement calls will print trace information to logs.
     */
    public CountingIdlingResource(String resourceName, boolean debugCounting) {
        this.resourceName = checkNotNull(resourceName);
        this.debugCounting = debugCounting;
    }

    @Override
    public String getName() {
        return resourceName;
    }

    @Override
    public boolean isIdleNow() {
        return counter.get() == 0;
    }

    @Override
    public void registerIdleTransitionCallback(ResourceCallback resourceCallback) {
        this.resourceCallback = resourceCallback;
    }

    /**
     * Increments the count of in-flight transactions to the resource being monitored.
     * <p/>
     * This method can be called from any thread.
     */
    public void increment() {
        int counterVal = counter.getAndIncrement();
        if (0 == counterVal) {
            becameBusyAt = SystemClock.uptimeMillis();
        }

        if (debugCounting) {
            Log.i(TAG, "Resource: " + resourceName + " in-use-count incremented to: " + (counterVal + 1));
        }
    }

    /**
     * Decrements the count of in-flight transactions to the resource being monitored.
     * <p/>
     * If this operation results in the counter falling below 0 - an exception is raised.
     *
     * @throws IllegalStateException if the counter is below 0.
     */
    public void decrement() {
        int counterVal = counter.decrementAndGet();

        if (counterVal == 0) {
            // we've gone from non-zero to zero. That means we're idle now! Tell espresso.
            if (null != resourceCallback) {
                resourceCallback.onTransitionToIdle();
            }
            becameIdleAt = SystemClock.uptimeMillis();
        }

        if (debugCounting) {
            if (counterVal == 0) {
                Log.i(TAG, "Resource: " + resourceName + " went idle! (Time spent not idle: " +
                        (becameIdleAt - becameBusyAt) + ")");
            } else {
                Log.i(TAG, "Resource: " + resourceName + " in-use-count decremented to: " + counterVal);
            }
        }
        checkState(counterVal > -1, "Counter has been corrupted!");
    }

    /**
     * Prints the current state of this resource to the logcat at info level.
     */
    public void dumpStateToLogs() {
        StringBuilder message = new StringBuilder("Resource: ")
                .append(resourceName)
                .append(" inflight transaction count: ")
                .append(counter.get());
        if (0 == becameBusyAt) {
            Log.i(TAG, message.append(" and has never been busy!").toString());
        } else {
            message.append(" and was last busy at: ")
                    .append(becameBusyAt);
            if (0 == becameIdleAt) {
                Log.w(TAG, message.append(" AND NEVER WENT IDLE!").toString());
            } else {
                message.append(" and last went idle at: ")
                        .append(becameIdleAt);
                Log.i(TAG, message.toString());
            }
        }
    }
}

}

我现在得到的异常如下:

ndroid.support.test.espresso.IdlingResourceTimeoutException: Wait for [FooServerCalls] to become idle timed out

当我运行测试时，正在填写用户名和密码，但从未调用过执行单击，几秒钟后我得到了异常。应该如何正确实现空闲资源？

编辑 --

我建议使用适用于 Android 的 Calabash。 Calabash 的工作原理类似，但不需要您更改应用代码进行测试。

最佳答案

就像其他答案所暗示的那样，countingIdlingResource 并不真正适用于您的用例。

我总是做的是添加一个接口(interface) - 我们称之为 ProgressListener - 作为具有等待资源的 Activity/fragment 的字段(异步后台工作，更长的网络 session ，等)以及每次显示或关闭进度时通知它的方法。

我假设您在 LoginActivity 中有凭据验证逻辑和对 Parse API 的调用，如果成功，它将调用 MainActivity 的 Intent 。

public class LoginActivity extends AppCompatActivity {

    private ProgressListener mListener;
     
    ...    

    public interface ProgressListener {
        public void onProgressShown();          
        public void onProgressDismissed();
    }
    
    public void setProgressListener(ProgressListener progressListener) {
        mListener = progressListener;
    }

    ...

    public void onLoginButtonClicked (View view) {
        String username = mUsername.getText().toString();
        String password = mPassword.getText().toString();
        
        // validate credentials for blanks and so on

        // show progress and call parse login in background method
        showProgress();
        ParseUser.logInInBackground(username,password, new LogInCallback() {
                    @Override
                    public void done(ParseUser parseUser, ParseException e) {
                        dismissProgress();
                        if (e == null){
                            // Success!, continue to MainActivity via intent
                            Intent intent = new Intent (LoginActivity.this, MainActivity.class);
                            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
                            startActivity(intent);
                        }
                        else {
                             // login failed dialog or similar.
                        }
                   }
               });
    }  
    
    private void showProgress() {
    // show the progress and notify the listener
    ... 
    notifyListener(mListener);
    }
    
    private void dismissProgress() {
    // hide the progress and notify the listener        
    ...
    notifyListener(mListener);
    }        

    public boolean isInProgress() {
    // return true if progress is visible 
    }

    private void notifyListener(ProgressListener listener) {
        if (listener == null){
            return;
        }
        if (isInProgress()){
            listener.onProgressShown();
        }
        else {
            listener.onProgressDismissed();
        }
    }
}

然后，只需执行 IdlingResource当资源通过其ResourceCallBack 由忙转为空闲时，类并覆盖其通信方法。

public class ProgressIdlingResource implements IdlingResource {

    private ResourceCallback resourceCallback;
    private LoginActivity loginActivity;
    private LoginActivity.ProgressListener progressListener;

    public ProgressIdlingResource(LoginActivity activity){
        loginActivity = activity;

        progressListener = new LoginActivity.ProgressListener() {
            @Override
            public void onProgressShown() {
            }
            @Override
            public void onProgressDismissed() {
                if (resourceCallback == null){
                    return ;
                }
            //Called when the resource goes from busy to idle.
            resourceCallback.onTransitionToIdle();
            }
        };

        loginActivity.setProgressListener (progressListener);
    }
    @Override
    public String getName() {
        return "My idling resource";
    }

    @Override
    public boolean isIdleNow() {
        // the resource becomes idle when the progress has been dismissed
        return !loginActivity.isInProgress();
    }

    @Override
    public void registerIdleTransitionCallback(ResourceCallback resourceCallback) {
        this.resourceCallback = resourceCallback;
    }
}

最后一步是在测试的 setUp() 方法中注册您的自定义空闲资源:

Espresso.registerIdlingResources(new ProgressIdlingResource((LoginActivity) getActivity()));

就是这样!现在 espresso 将等待您的登录过程完成，然后继续进行所有其他测试。

如果我不够清楚或者这正是您所需要的，请告诉我。

关于android - 如何使用 Espresso 空闲资源进行网络调用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30733718/