Test Runner and Configuration

/**
 * Loads and runs a test in a SandboxClassLoader to provide Android runtime simulation.
 * Use as @RunWith(RobolectricTestRunner.class) on test classes.
 */
public class RobolectricTestRunner extends SandboxTestRunner {
    // Constructor creates sandboxed test environment
    public RobolectricTestRunner(Class<?> testClass) throws InitializationError;
}

@RunWith(RobolectricTestRunner.class)
public class MyAndroidTest {
    @Test
    public void testSomething() {
        // Test code runs in Android simulation
    }
}

/**
 * Parameterized test runner extending RobolectricTestRunner.
 * Allows running tests with different parameters or configurations.
 */
public class ParameterizedRobolectricTestRunner extends RobolectricTestRunner {
    public ParameterizedRobolectricTestRunner(Class<?> testClass) throws InitializationError;
}

/**
 * Configuration settings that can be used on a per-class or per-test basis.
 * Controls Android simulation parameters and test environment setup.
 */
@Documented
@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
public @interface Config {
    
    /** Android SDK levels to emulate. Will also be set as Build.VERSION.SDK_INT */
    int[] sdk() default {};
    
    /** Minimum Android SDK level for multi-version tests */
    int minSdk() default -1;
    
    /** Maximum Android SDK level for multi-version tests */
    int maxSdk() default -1;
    
    /** Font scale factor (default 1.0f). Users can adjust this in Android U+ */
    float fontScale() default 1.0f;
    
    /** 
     * @deprecated Android manifest file path
     * Use build system integration instead
     */
    @Deprecated
    String manifest() default "--default";
    
    /** Application class to use, overrides AndroidManifest.xml setting */
    Class<? extends Application> application() default DefaultApplication.class;
    
    /** 
     * @deprecated Java package name for R.class
     * Override applicationId in build system instead
     */
    @Deprecated
    String packageName() default "";
    
    /** 
     * Device configuration qualifiers like "fr-normal-port-hdpi"
     * If prefixed with '+', overlays on broader-scoped qualifiers
     */
    String qualifiers() default "";
    
    /** 
     * @deprecated Resource directory path
     * Use build system integration instead
     */
    @Deprecated
    String resourceDir() default "res";
    
    /** 
     * @deprecated Asset directory path  
     * Use build system integration instead
     */
    @Deprecated
    String assetDir() default "assets";
    
    /** Additional shadow classes to enable */
    Class<?>[] shadows() default {};
    
    /** Additional instrumented packages */
    String[] instrumentedPackages() default {};
    
    /** 
     * @deprecated Android library dependencies
     * Use build system integration instead
     */
    @Deprecated
    String[] libraries() default {};
}

public @interface Config {
    // Special values
    String NONE = "--none";
    String DEFAULT_VALUE_STRING = "--default";
    int DEFAULT_VALUE_INT = -1;
    
    // SDK constants
    int ALL_SDKS = -2;      // Run on all supported SDKs
    int TARGET_SDK = -3;    // Use target SDK
    int OLDEST_SDK = -4;    // Use oldest supported SDK  
    int NEWEST_SDK = -5;    // Use newest supported SDK
    
    // Default configuration values
    String DEFAULT_MANIFEST_NAME = "AndroidManifest.xml";
    String DEFAULT_RES_FOLDER = "res";
    String DEFAULT_ASSET_FOLDER = "assets";
    Class<? extends Application> DEFAULT_APPLICATION = DefaultApplication.class;
}

// Single SDK version
@Config(sdk = 28)
public class MyTest { }

// Multiple SDK versions
@Config(sdk = {28, 29, 30})
public class CrossVersionTest { }

// SDK range
@Config(minSdk = 21, maxSdk = 30)
public class RangeTest { }

// Device configuration
@Config(qualifiers = "xlarge-land-mdpi")
public class TabletTest { }

// Custom application
@Config(application = MyCustomApplication.class)
public class CustomAppTest { }

// Additional shadows
@Config(shadows = {MyCustomShadow.class})
public class CustomShadowTest { }

// Method-level override
@Config(sdk = 28)
public class MyTest {
    @Config(sdk = 30)  // Overrides class-level config
    @Test
    public void newSdkTest() { }
}

/**
 * Builder for creating Config instances programmatically.
 * Useful for dynamic configuration or test parameterization.
 */
public static class Builder {
    public Builder();
    public Builder(Config config);
    
    public Builder setSdk(int... sdk);
    public Builder setMinSdk(int minSdk);
    public Builder setMaxSdk(int maxSdk);
    public Builder setManifest(String manifest);
    public Builder setQualifiers(String qualifiers);
    public Builder setFontScale(float fontScale);
    
    /** @deprecated Use build system integration */
    @Deprecated
    public Builder setPackageName(String packageName);
    
    /** @deprecated Use build system integration */
    @Deprecated  
    public Builder setResourceDir(String resourceDir);
    
    /** @deprecated Use build system integration */
    @Deprecated
    public Builder setAssetDir(String assetDir);
    
    public Builder setShadows(Class<?>... shadows);
    public Builder setInstrumentedPackages(String... instrumentedPackages);
    public Builder setApplication(Class<? extends Application> application);
    
    /** @deprecated Use build system integration */
    @Deprecated
    public Builder setLibraries(String... libraries);
    
    public Builder overlay(Config overlayConfig);
    public Implementation build();
    
    public static Builder defaults();
    public static boolean isDefaultApplication(Class<? extends Application> clazz);
}

/**
 * Concrete implementation of Config annotation.
 * Can be created from Properties or programmatically.
 */
public static class Implementation implements Config {
    public Implementation(/* parameters for all config values */);
    
    public static Config fromProperties(Properties properties);
    
    // Implements all Config interface methods
    public int[] sdk();
    public int minSdk();
    public int maxSdk();
    public String manifest();
    public float fontScale();
    public Class<? extends Application> application();
    public String qualifiers();
    public String packageName();
    public String resourceDir();
    public String assetDir();
    public Class<?>[] shadows();
    public String[] instrumentedPackages();
    public String[] libraries();
}

// Create from properties
Properties props = new Properties();
props.setProperty("sdk", "28,29,30");
props.setProperty("qualifiers", "xlarge-land");
Config config = Config.Implementation.fromProperties(props);

// Create with builder
Config config = new Config.Builder()
    .setSdk(28, 29, 30)
    .setQualifiers("xlarge-land-mdpi")
    .setApplication(MyApplication.class)
    .build();

# robolectric.properties
sdk=21,28,29,30
minSdk=21
maxSdk=30
qualifiers=normal-hdpi

-Drobolectric.sdk=28
-Drobolectric.qualifiers=xlarge-land-mdpi