没有错误，Android Studio仍然表示“没有发现测试”

Question

我正试图为我的主要活动编写一个仪器测试。我遵循了这里给出的答案。但是Android Studio找不到任何测试。我在androidTest文件夹中有applicationTest.java类。以下是这堂课的内容：

package com.example.monicamarcus.mymusicplayer

import android.app.Activity;
import android.test.ActivityInstrumentationTestCase2;
import com.example.monicamarcus.mymusicplayer.MainActivity;

public class ApplicationTest extends ActivityInstrumentationTestCase2<MainActivity> { 
    public ApplicationTest() {
        super(MainActivity.class);
    }

    public void testNextTrackButton() throws Exception {
        Activity activity = getActivity();

        Button nextButton = (Button) activity.findViewById(R.id.nextTrackBt);
        activity.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                nextButton.performClick();
                assertTrue(currentPosition < songList.size());
            }});
        activity.finish();
    }
}

这个测试类出了什么问题？还是测试？我没有得到任何错误，它只是没有找到任何测试运行。运行ApplicationTest后，输出以以下行结束：

Running tests
Test running startedFinish
Empty test suite.

以下是该应用程序的build.gradle文件：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "com.example.monicamarcus.mymusicplayer"
        minSdkVersion 16
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
        testApplicationId "app.src.androidTest.java.com.example.monicamarcus.mymusicplayer"
        testInstrumentationRunner "android.test.InstrumentationTestRunner"
    }
    buildTypes {
        debug {
            minifyEnabled false
        }
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

android {
    useLibrary 'org.apache.http.legacy'
}

android {

    sourceSets {

        androidTest {
            java.srcDirs = ['androidTest/java']
        }

    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.1.1'
    androidTestCompile 'junit:junit:4.12'
}

以下是测试运行的输出：

Testing started at 1:56 PM ...
Target device: gt_i8190n-4790068ee9a750c6
Installing APK: /Users/monicamarcus/AndroidStudioProjects/MyMusicPlayer/app/build/outputs/apk/app-debug.apk
Uploading file to: /data/local/tmp/com.example.monicamarcus.mymusicplayer
Installing com.example.monicamarcus.mymusicplayer
DEVICE SHELL COMMAND: pm install -r "/data/local/tmp/com.example.monicamarcus.mymusicplayer"
pkg: /data/local/tmp/com.example.monicamarcus.mymusicplayer
Success


Installing APK: /Users/monicamarcus/AndroidStudioProjects/MyMusicPlayer/app/build/outputs/apk/app-debug-androidTest-unaligned.apk
Uploading file to: /data/local/tmp/app.src.androidTest.java.com.example.monicamarcus.mymusicplayer
Installing app.src.androidTest.java.com.example.monicamarcus.mymusicplayer
DEVICE SHELL COMMAND: pm install -r "/data/local/tmp/app.src.androidTest.java.com.example.monicamarcus.mymusicplayer"
pkg: /data/local/tmp/app.src.androidTest.java.com.example.monicamarcus.mymusicplayer
Success


Running tests
Test running startedFinish
Empty test suite.

在我做了一些更改（如果有人感兴趣，我可以发布它们）之后，运行仪表测试类的结果如下：“运行测试。测试运行开始了。测试运行失败了：没有测试结果。空测试套件。”没有人有这种测试的经验？

Answer 1

在build.gradle中，TestApplicationID看起来非常奇怪。我将删除它和TestInstrumentationRunner。默认值应该没问题。具体地说，如果您没有指定TestApplicationID，它将通过在ApplicationID后面追加“.test”来创建。