Robolectric Flavour Test Runner (fix paths when you have an app with flavouring)

RobolectricFlavourTestRunner.java

package au.com.myapp;


import org.junit.runners.model.InitializationError;
import org.robolectric.RobolectricTestRunner;
import org.robolectric.annotation.Config;
import org.robolectric.manifest.AndroidManifest;
import org.robolectric.res.FileFsFile;
import org.robolectric.util.ReflectionHelpers;

/**
 * Created by cedric on 9/03/2017.
 * Robolectric: 3.3.1
 *
 * Usage:
 * Add the following line at above your Test class name
   @RunWith(RobolectricFlavourTestRunner.class)
   @Config(constants = BuildConfig.class, sdk = 24)
   public class MainActivityTest {
      @Test
      public void mainActivityCanStart() {
        MainActivity mainActivity = Robolectric.setupActivity(MainActivity.class);
        assertNotNull(mainActivity);
      }
   }
 */

public class RobolectricFlavourTestRunner extends RobolectricTestRunner {
    private static final String BUILD_OUTPUT = "app/build/intermediates"; // this fix the path

    public RobolectricFlavourTestRunner(Class<?> klass) throws InitializationError {
        super(klass);
    }

    @Override
    protected AndroidManifest getAppManifest(Config config) {
        if (config.constants() == Void.class) {
            //Log.e("RobolectricFlavorTest", "Field 'constants' not specified in @Config annotation");
            //Log.e("RobolectricFlavorTest", "This is required when using RobolectricGradleTestRunner!");
            throw new RuntimeException("No 'constants' field in @Config annotation!");
        }

        final String type = getType(config);
        final String flavor = getFlavor(config);
        final String applicationId = getApplicationId(config);

        final FileFsFile res;
        if (FileFsFile.from(BUILD_OUTPUT, "res", flavor, type).exists()) {
            res = FileFsFile.from(BUILD_OUTPUT, "res", flavor, type);
        } else {
            // Use res/merged if the output directory doesn't exist for Data Binding compatibility
            res = FileFsFile.from(BUILD_OUTPUT, "res/merged", flavor, type);
        }

        final FileFsFile assets = FileFsFile.from(BUILD_OUTPUT, "assets", flavor, type);

        final FileFsFile manifest;
        if (FileFsFile.from(BUILD_OUTPUT, "manifests").exists()) {
            manifest = FileFsFile.from(BUILD_OUTPUT, "manifests", "full", flavor, type, "AndroidManifest.xml");
        } else {
            // Fallback to the location for library manifests
            manifest = FileFsFile.from(BUILD_OUTPUT, "bundle", flavor, type, "AndroidManifest.xml");
        }

        System.out.println("Robolectric assets directory: " + assets.toString());
        System.out.println("   Robolectric res directory: " + res.toString());
        System.out.println("   Robolectric manifest path: " + manifest.toString());
        System.out.println("    Robolectric package name: " + applicationId);
        return new AndroidManifest(manifest, res, assets, applicationId);
    }

    private String getType(Config config) {
        try {
            return ReflectionHelpers.getStaticField(config.constants(), "BUILD_TYPE");
        } catch (Throwable e) {
            return null;
        }
    }

    private String getFlavor(Config config) {
        try {
            return ReflectionHelpers.getStaticField(config.constants(), "FLAVOR");
        } catch (Throwable e) {
            return null;
        }
    }

    private String getApplicationId(Config config) {
        try {
            return ReflectionHelpers.getStaticField(config.constants(), "APPLICATION_ID");
        } catch (Throwable e) {
            return null;
        }
    }
}