Android Room can not create JSON schema for testing migrations

Question

I have created migration from 1 to 2 version of my database.

I have the app in a few modules like:

• app
• data
• domain

I have tried adding this into build.gradle of app and data modules:

javaCompileOptions {
        annotationProcessorOptions {
            arguments = ["room.schemaLocation":  "$projectDir/schemas".toString()]
        }
    }

    sourceSets {
        androidTest.assets.srcDirs += files("$projectDir/schemas".toString())
    }

Here is my MigrationTest class:

@RunWith(AndroidJUnit4.class)
public class MigrationTest {

private static final String TEST_DB = "migration-test";

@Rule public MigrationTestHelper helper;

private Profile profile;

public MigrationTest() {
helper = new MigrationTestHelper(
    InstrumentationRegistry.getInstrumentation(),
    AppDatabase.class.getCanonicalName(),
    new FrameworkSQLiteOpenHelperFactory());
}

@Before
public void setUp(){
profile = createProfile();
}

@Test public void migrate1To2() throws IOException {
    SupportSQLiteDatabase db = helper.createDatabase(TEST_DB, 1);
    insertProfile(db);
    db.close();
    AppDatabase database = (AppDatabase) helper.runMigrationsAndValidate(TEST_DB, 2, true, MIGRATION_1_2);
    Single<ProfileData> profileDataSingle = database.profileDao().getById("userId");
    ProfileData profileData = profileDataSingle.blockingGet();
    Profile currentProfile = ProfileMapper.transform(profileData);
    assertEquals(currentProfile.getUserId(), profile.getUserId());
}

Here is failing test:

java.io.FileNotFoundException: Cannot find the schema file in the assets folder. Make sure to include the exported json schemas in your test assert inputs. See https://developer.android.com/topic/libraries/architecture/room.html#db-migration-testing for details. Missing file: org.app.app.data.sql.AppDatabase/1.json

Answer 1

For Kotliners:

android{
    defaultConfig {
        // ...
        kapt {
            arguments {
                arg("room.schemaLocation", "$projectDir/schemas")
            }
        }
    }
    sourceSets {
        getByName("androidTest"){
            assets.srcDirs(File(projectDir, "schemas"))
        }
    }
}