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.

Robolectric supports running unit tests for 14 different versions of Android, ranging from Lollipop (API level 21) to U (API level 34).

Usage

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

@RunWith(AndroidJUnit4.class)
public class MyActivityTest {

  @Test
  public void clickingButton_shouldChangeResultsViewText() {
    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 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 "junit:junit:4.13.2"
testImplementation "org.robolectric:robolectric:4.13"

Building and Contributing

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

To get Robolectric up and running on your machine, check out this guide.

To get a high-level overview of Robolectric's architecture, check out ARCHITECTURE.md.

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 the master and may contain bugs.

build.gradle

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

dependencies {
    testImplementation "org.robolectric:robolectric:4.14-SNAPSHOT"
}