前言

UI单元测试使用官方的Espresso
在开发中对于重要的功能可编写单元测试,为防止后期的修改影响功能,每次开发完跑一遍测试即可保证功能的完整性

  1. 点击change按钮：设置内容到TextView上
  2. 点击open按钮：打开一个Activity,同时把内容传递过去,用来显示到TextView上

    Espresso依赖

    1
    2
    3
    4
    5
    6
    7
    8
    dependencies {
    	//test
        testImplementation 'junit:junit:4.12'
        androidTestImplementation 'androidx.test:runner:1.1.0'
        androidTestImplementation 'androidx.test:rules:1.1.0'
        //espresso
        androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
    }

环境依赖

1
2
3
4
5
android {
    defaultConfig {
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
}

添加单元测试任务

  1. Run>Edit Configurations
  2. 添加一个Android Instrumented Tests
  3. 选择对应的module
  4. 选择真机或者模拟器
  5. 如果选择真机：关闭开发者选项>绘画>窗口动画缩放;过滤动画缩放;动画程序时长缩放

    编写单元测试

    我们先验证应用是否开启了,直接验证是否有Hello World
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    @RunWith(AndroidJUnit4.class)
    @LargeTest
    public class ChangeTextBehaviorTest {

    	@Rule
        public ActivityTestRule<MainActivity> activityRule
                = new ActivityTestRule<>(MainActivity.class, false, true);

        @Test
        public void listGoesOverTheFold() {
            onView(withText("Hello world!")).check(matches(isDisplayed()));
        }
    }
  • 其中@LargeTest可根据自己情况来改变,具体见下图
    链接图片
  • @Rule定义测试启动的Activity
  • @Test来测试方法
  • 常用的Espresso的API
  1. onView 查找元素;onData() 查找AdapterView元素

    withText()通过文字查找

    withId()通过id查找
allOf()匹配多个条件-org.hamcrest.Matchers
  2. perform 执行操作

    click点击

    typeText点击并且输入一个值;最好结合closeSoftKeyboard
scrollTo滑动-onView必须是ScrollView
pressKey按键
clearText清空view的文字
  3. check 验证结果

    matches

  4. 所有的API可见官方给出的图示
    链接图片

如果我们启动的Activity不是MainActivity,而且需要intent传值,则可以使用下面的代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
@RunWith(AndroidJUnit4.class)
@LargeTest
public class TextShowTextActivity {

    private static final String MESSAGE = "12312";

    @Rule
    public ActivityTestRule<ShowTextActivity> activityRule
            = new ActivityTestRule<ShowTextActivity>(ShowTextActivity.class, false, true){
        @Override
        protected Intent getActivityIntent() {
            Intent result = new Intent();
            result.putExtra(ShowTextActivity.KEY_EXTRA_MESSAGE, MESSAGE);
            return result;
        }
    };

    @Test
    public void listGoesOverTheFold() {
        onView(withText(MESSAGE)).check(matches(isDisplayed()));
    }

}

使用intent单独测试Activity

即可以获取即将打开Activity的intent来检查一个Activity的完成性

  • 官方指南

  • 依赖

    1
    2
    3
    4
    dependencies {
    	//intent
        androidTestImplementation 'androidx.test.espresso:espresso-intents:3.1.0'
    }

  • 改变Rule

    1
    2
    @Rule
    public IntentsTestRule<MyActivity> intentsTestRule = new IntentsTestRule<>(MyActivity.class);

测试代码如下

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
@RunWith(JUnit4.class)
@LargeTest
public class ChangePageBehaviorTest {

    private static final String MESSAGE = "This is a test";
    private static final String PACKAGE_NAME = "com.mlc.android_test";

    @Rule
    public IntentsTestRule<MainActivity> intentsRule =
            new IntentsTestRule<>(MainActivity.class);
    @Test
    public void verifyMessageSentToMessageActivity() {

        // Types a message into a EditText element.
        onView(withId(R.id.editTextUserInput))
                .perform(typeText(MESSAGE), closeSoftKeyboard());

        // Clicks a button to send the message to another
        // activity through an explicit intent.
        onView(withId(R.id.activityChangeTextBtn)).perform(click());

        // Verifies that the DisplayMessageActivity received an intent
        // with the correct package name and message.
        intended(allOf(
                hasComponent(hasShortClassName(".ShowTextActivity")),
                toPackage(PACKAGE_NAME),
                hasExtra(ShowTextActivity.KEY_EXTRA_MESSAGE, MESSAGE)));
    }
}

UiAutomator

UIAutomator主要用于多个应用之间的测试
由于目前没有好的例子,Demo中也只是使用了官方的用例,这里只给出链接

  • 官方指南

    测试原理浅析

    首先我们需要了解Activity的开启流程,可以参考我总结的Activity启动流程
    Activity需要通过Instrumentation来与系统交互的,单元测试中其实也一样，通过它来开启Activity
    我们从ActivityTestRule来作为入口
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    #ActivityTestRule
    /**
      * Launches the Activity under test.
      */
     public T launchActivity(@Nullable Intent startIntent) {
       //...
        if (null == startIntent) {
          startIntent = getActivityIntent();
          if (null == startIntent) {        
            startIntent = new Intent(Intent.ACTION_MAIN);
          }
        }
        if (null == startIntent.getComponent()) {
          startIntent.setClassName(targetPackage, activityClass.getName());
        }
        T hardActivityRef = activityClass.cast(instrumentation.startActivitySync(startIntent));
        //...
        return hardActivityRef;
      }

启动Activity是通过launchActivity()方法来启动，看做了什么操作:

  1. 设置intent
  2. 使用instrumentation.startActivitySync()开启Activity
    到这里我们已经清楚单元测试也与普通的应用一样，是用instrumentation来开启Activity

    题外话

    其实这个instrumentation是MonitoringInstrumentation
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    #MonitoringInstrumentation

      @Override
      public Activity startActivitySync(final Intent intent) {
        checkNotMainThread();   
        Future<Activity> startedActivity =
            executorService.submit(
                new Callable<Activity>() {
                  @Override
                  public Activity call() {
                    return MonitoringInstrumentation.super.startActivitySync(intent);
                  }
                });

        try {
          return startedActivity.get(START_ACTIVITY_TIMEOUT_SECONDS, TimeUnit.SECONDS);
        } catch (TimeoutException te) {
          dumpThreadStateToOutputs("ThreadState-startActivityTimeout.txt");
          startedActivity.cancel(true);
          throw new RuntimeException(
              String.format(
                  "Could not launch intent %s within %s seconds."
                      + " Perhaps the main thread has not gone idle within a reasonable amount of "
                      + "time? There could be an animation or something constantly repainting the "
                      + "screen. Or the activity is doing network calls on creation? See the "
                      + "threaddump logs. For your reference the last time the event queue was idle "
                      + "before your activity launch request was %s and now the last time the queue "
                      + "went idle was: %s. If these numbers are the same your activity might be "
                      + "hogging the event queue.",
                  intent,
                  START_ACTIVITY_TIMEOUT_SECONDS,
                  lastIdleTimeBeforeLaunch,
                  lastIdleTime.get()));
        } catch (ExecutionException ee) {
          throw new RuntimeException("Could not launch activity", ee.getCause());
        } catch (InterruptedException ie) {
          Thread.currentThread().interrupt();
          throw new RuntimeException("interrupted", ie);
        }
      }

我们看到是通过线程池来开启，获取Future后，设置了超时时间45s。在我们设置activity有问题时经常出现

Tips

  • 真机运行可能需要安装应用后开启手机允许后台弹出界面权限