Customizing Robolectric

Many aspects of Robolectric can be configured at runtime by subclassing RobolectricTestRunner to create a custom test runner.

Test Setup

Location of AndroidManifest.xml and resources

By default, Robolectric will look for your AndroidManifest.xml file in the current working directory, and will look for your resource files in the "res" directory in the same place.

You can override these defaults in your custom test runner by specifying alternate values in the super constructor call:

public class CustomTestRunner extends RobolectricTestRunner {
    public CustomTestRunner(Class testClass) throws InitializationError {
        // defaults to "AndroidManifest.xml", "res" in the current directory
        super(testClass, new File("../other/project-root"));
    }
}

Application class

By default, Robolectric will create a new instance of the application class specified in AndroidManifest.xml for each test.

You may override this behavior in your custom test runner by overriding the createApplication method:

public class CustomTestRunner extends RobolectricTestRunner {
    public CustomTestRunner(Class testClass) throws InitializationError {
        super(testClass);
    }

    @Override protected Application createApplication() {
        return new CustomApplication();
    }
}

Test setup and tear-down

Robolectric resets some internal state automatically before every test, including:

• stored SharedPreferences
• displayed Toasts and Dialogs
• enqueued Looper work

Robolectric provides hooks for specifying your own code to run before and after every test in every test class that uses your test runner. This can be especially useful for resetting state between tests, or triggering dependency injection (e.g. with RoboGuice).

public class CustomTestRunner extends RobolectricTestRunner {
    public CustomTestRunner(Class testClass) throws InitializationError {
        super(testClass);
    }

    @Override public void prepareTest(Object test) {
    }

    @Override public void beforeTest(Method method) {
    }

    @Override public void afterTest(Method method) {
    }
}

Custom Shadows

Robolectric provides shadow implementations of many Android classes, but you may find that you want to add your own, or change the way a shadow works. You can do this by registering your shadow classes in the beforeTest(Method method) method.

public class CustomTestRunner extends RobolectricTestRunner {
    public CustomTestRunner(Class testClass) throws InitializationError {
        super(testClass);
    }

    @Override public void beforeTest(Method method) {
        Robolectric.bindShadowClass(ShadowBitmapFactory.class);
        Robolectric.bindShadowClass(ShadowDrawable.class);
        Robolectric.bindShadowClass(ShadowGeocoder.class);
    }
}