Configuring Robolectric

Several aspects of Robolectric’s behavior can be configured at runtime, using robolectric.properties files for package-level configuration, or @Config annotations for class-level or method-level configuration.

@Config Annotation

To configure Robolectric for a single test class or method, use the @Config annotation. The annotation can be applied to classes and methods; values specified at the method level will override values specified at the class level.

Base classes are also searched for annotations, so if you find yourself specifying the same values on a large number of tests, you can create a base class and move your @Config annotation to that class.

  @Config(sdk=JELLYBEAN_MR1,
      shadows={ShadowFoo.class, ShadowBar.class})
  public class SandwichTest {
  }

robolectric.properties File

To configure all Robolectric tests within a package or group of packages, create a file named robolectric.properties in the appropriate package. Generally, this file would be placed within the appropriate package directory under src/test/resources in your project tree. Robolectric will search for properties files up the hierarchy of packages (including the unnamed default package at the top level), with values in deeper packages overriding values in more shallow packages. When test classes or methods have @Config annotations, those override any config from properties files.

Below is an example:

# src/test/resources/com/mycompany/app/robolectric.properties
sdk=18
shadows=my.package.ShadowFoo,my.package.ShadowBar

Version note: Prior to Robolectric 3.1.3, only a top-level robolectric.properties file may be specified.

Global Configuration

If you wish to change the default for any configurable value for all your tests, you may extend RobolectricTestRunner and override the buildGlobalConfig() method, then specify your custom test runner using the @RunWith annotation.

Configurables

The following examples show how to handle common configuration tasks. For clarity, @Config annotations are used, but any of these values may also be configured using properties files.

Configure SDK Level

By default, Robolectric will run your code against the targetSdkVersion specified in your manifest. If you want to test your code under a different SDK, you can specify the SDK using the sdk, minSdk and maxSdk config properties:

@Config(sdk = { JELLY_BEAN, JELLY_BEAN_MR1 })
public class SandwichTest {

    public void getSandwich_shouldReturnHamSandwich() {
      // will run on JELLY_BEAN and JELLY_BEAN_MR1
    }

    @Config(sdk = KITKAT)
    public void onKitKat_getSandwich_shouldReturnChocolateWaferSandwich() {
      // will run on KITKAT
    }
    
    @Config(minSdk=LOLLIPOP)
    public void fromLollipopOn_getSandwich_shouldReturnTunaSandwich() {
      // will run on LOLLIPOP, M, etc.
    }
}

Note that sdk and minSdk/maxSdk may not be specified in the same config annotation or file; however, minSdk and maxSdk may be specified together. If any of them is present, they override any SDK specification from a less-specific configuration location.

Version note: Prior to Robolectric 3.2, minSdk and maxSdk are ignored, and NEWEST, OLDEST, and TARGET are not supported. Also, only integers corresponding to API levels may be specified in a properties file.

Configure Application Class

Robolectric will attempt to create an instance of your Application class as specified in the manifest. If you want to provide a custom implementation, you can specify it by setting:

@Config(application = CustomApplication.class)
public class SandwichTest {

    @Config(application = CustomApplicationOverride.class)
    public void getSandwich_shouldReturnHamSandwich() {
    }
}

Configure Qualifiers

You can explicitly configure the set of resource qualifiers in effect for a test:

public class SandwichTest {

    @Config(qualifiers = "fr-xlarge")
    public void getSandwichName() {
      assertThat(sandwich.getName()).isEqualTo("Grande Croque Monégasque");
    }
}

See Using Qualifiers for more details.

System Properties

Some additional options can be configured globally by setting these system properties:

• robolectric.enabledSdks — Comma-separated list of SDK levels or names (e.g. 19, 21 or KITKAT, LOLLIPOP) which are enabled for this process. Only tests targetted at the listed SDKs will be run. By default, all SDKs are enabled.
• robolectric.offline — Set to true to disable runtime fetching of jars.
• robolectric.usePreinstrumentedJars — If true, Robolectric will use instrumented jars to reduce instrumentation overhead. If changes are made to instrumentation, this can be set to false to ensure the changes are included when building Robolectric.
• robolectric.dependency.dir — When in offline mode, specifies a folder containing runtime dependencies.
• robolectric.dependency.repo.id — Set the ID of the Maven repository to use for the runtime dependencies (default mavenCentral).
• robolectric.dependency.repo.url — Set the URL of the Maven repository to use for the runtime dependencies (default https://repo.maven.apache.org/maven2/).
• robolectric.dependency.repo.username - Username of repository that you defined in robolectric.dependency.repo.url.
• robolectric.dependency.repo.password - Password of repository that you defined in robolectric.dependency.repo.url.
• robolectric.logging.enabled — Set to true to enable debug logging.

Since Robolectric 4.9.1, you can now add these parameters :

• robolectric.dependency.proxy.host — Set the host of the proxy to use for the runtime dependencies.
• robolectric.dependency.proxy.port — Set the port number of the proxy to use for the runtime dependencies (default 0).

When using Gradle, you can configure the System Properties for unit tests with the all block (see here). For example, to override the Maven repository URL and ID to download the runtime dependencies from a repository other than Maven Central:

android {
  testOptions {
    unitTests.all {
      systemProperty 'robolectric.dependency.repo.url', 'https://local-mirror/repo'
      systemProperty 'robolectric.dependency.repo.id', 'local'
      // Username and password only needed when local repository
      // needs account information.
      systemProperty 'robolectric.dependency.repo.username', 'username'
      systemProperty 'robolectric.dependency.repo.password', 'password'
      
      // Since Robolectric 4.9.1, these are available
      systemProperty 'robolectric.dependency.proxy.host', project.findProperty("systemProp.https.proxyHost") ?: System.getenv("ROBOLECTRIC_PROXY_HOST")
      systemProperty 'robolectric.dependency.proxy.port', project.findProperty("systemProp.https.proxyPort") ?: System.getenv("ROBOLECTRIC_PROXY_PORT")
    }
  }
}

ConscryptMode

Starting in Robolectric 4.9, Robolectric can currently either use Conscrypt and BouncyCastle or just BouncyCastle as the security provider. In order to migrate tests over time, there is a ConscryptMode annotation that controls whether Conscrypt is loaded as the default security provider with BouncyCastle as backup.

• If ConscryptMode is ON, it will install Conscrypt and BouncyCastle.
• If ConscryptMode is OFF, it will only install BouncyCastle.

This is closer to to the way that it works on real android. Robolectric will search for a requested security primitive from Conscrypt first. If it does not support it, Robolectric will try BouncyCastle second.