robolectric / Robolectric

Robolectric is the industry-standard unit testing framework for Android. With Robolectric, your tests run in a simulated Android environment inside a JVM, without the overhead and flakiness of an emulator. Robolectric tests routinely run 10x faster than those on cold-started emulators.

Robolectic supports running unit tests for 15 different versions of Android, ranging from Jelly Bean (API level 16) to S (API level 31).

Usage

Here's an example of a simple test written using Robolectric:

@RunWith(AndroidJUnit4.class)
public class MyActivityTest {

  @Test
  public void clickingButton_shouldChangeResultsViewText() throws Exception {
    Activity activity = Robolectric.setupActivity(MyActivity.class);

    Button button = (Button) activity.findViewById(R.id.press_me_button);
    TextView results = (TextView) activity.findViewById(R.id.results_text_view);

    button.performClick();
    assertThat(results.getText().toString(), equalTo("Testing Android Rocks!"));
  }
}

For more information about how to install and use Robolectric on your project, extend its functionality, and join the community of contributors, please visit http://robolectric.org.

Install

Starting a New Project

If you'd like to start a new project with Robolectric tests you can refer to deckard (for either maven or gradle) as a guide to setting up both Android and Robolectric on your machine.

build.gradle:

testImplementation "org.robolectric:robolectric:4.7.3"

Building And Contributing

Robolectric is built using Gradle. Both IntelliJ and Android Studio can import the top-level build.gradle file and will automatically generate their project files from it.

Robolectric supports running tests against multiple Android API levels. The work it must do to support each API level is slightly different, so its shadows are built separately for each. To build shadows for every API version, run:

./gradlew clean assemble testClasses --parallel

Using Snapshots

If you would like to live on the bleeding edge, you can try running against a snapshot build. Keep in mind that snapshots represent the most recent changes on master and may contain bugs.

build.gradle:

repositories {
    maven { url "https://oss.sonatype.org/content/repositories/snapshots" }
}

dependencies {
    testImplementation "org.robolectric:robolectric:4.8-SNAPSHOT"
}