xref: /aosp_15_r20/external/robolectric/README.md (revision e6ba16074e6af37d123cb567d575f496bf0a58ee)

<a name="README">[<img src="https://rawgithub.com/robolectric/robolectric/master/images/robolectric-horizontal.png"/>](https://robolectric.org)</a>

[![Build Status](https://github.com/robolectric/robolectric/actions/workflows/tests.yml/badge.svg)](https://github.com/robolectric/robolectric/actions?query=workflow%3Atests)
[![GitHub release](https://img.shields.io/github/release/robolectric/robolectric.svg?maxAge=60)](https://github.com/robolectric/robolectric/releases)

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:

```java
@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](https://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](https://github.com/robolectric/deckard-maven) or [Gradle](https://github.com/robolectric/deckard-gradle)) as a guide to setting up both Android and Robolectric on your machine.

### `build.gradle`

```groovy
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](https://robolectric.org/building-robolectric/).

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

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

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