[Android] Setting a quick instrumentation test environment with Espresso + JUnit + Mockito

1.- Gradle dependencies – global build.gradle

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.1.0'
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.4'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
        maven { url "https://jitpack.io" }
    }
} 

2.- Gradle dependencies – app/build.gradle

defaultConfig {
    applicationId "..."
    minSdkVersion 15
    testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'
}

dependencies { 
    // ... testCompile 'junit:junit:4.12' 
    androidTestCompile 'com.google.dexmaker:dexmaker:1.2' 
    androidTestCompile('com.google.dexmaker:dexmaker-mockito:1.2') { 
        exclude group: 'org.hamcrest', module: 'hamcrest-core' 
    }
    androidTestCompile 'com.android.support.test:runner:0.4.1' 
    androidTestCompile 'com.android.support.test:rules:0.4.1'
    androidTestCompile 'org.mockito:mockito-core:1.10.19' 
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.1') 
    { 
        exclude group: 'javax.inject', module: 'javax.inject'
        exclude group: 'com.squareup', module: 'javawriter' 
    }
    androidTestCompile('com.android.support.test.espresso:espresso-contrib:2.2.1') 
    { 
        exclude module: 'support-annotations' 
        exclude module: 'recyclerview-v7' exclude module: 'support-v4' 
    }
    androidTestCompile('com.android.support.test.espresso:espresso-intents:2.2.1') 
    testCompile "org.mockito:mockito-core:1.9.5" 
    testCompile 'org.mockito:mockito-all:1.9.5' 
}

configurations.all { 
    resolutionStrategy.force 'com.android.support:support-annotations:23.0.1' 
}

3.- Sample test (androidTest/com/package/name folder)

@RunWith(AndroidJUnit4.class) @LargeTest
public class IssuesActivityTest {
    @Rule
    public IntentsTestRule<IssuesActivity> activityRule =
            new IntentsTestRule<>(IssuesActivity.class, true, false);

    @Test
    public void shouldDisplayToolbarOnStart() {
        startActivity();

        onView(withId(R.id.toolbar)).check(matches(isDisplayed()));
    }

    private IssuesActivity startActivity() {
        return activityRule.launchActivity(null);
    }
}

And that’s all folks