Room Migration test failing : schema not found - testing

Question

I'm try to implement android test for my room database, to test migrations. For this, I generated the schema needed, and I follow the step from the Android documentation.
When I run my migration test, it shows that the schema cannot be loaded, despite I added the assets line in the Gradle build. I added multiple other build types, it was not helping. I'm making something wrong, but I can't find where.
Room Version : 2.3.0
The error :
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/training/data-storage/room/migrating-db-versions#export-schema for details. Missing file: Asset file database.Sauvegarde/1.json not found
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/training/data-storage/room/migrating-db-versions#export-schema for details. Missing file: Asset file database.Sauvegarde/1.json not found
at androidx.room.testing.MigrationTestHelper.loadSchema(MigrationTestHelper.java:326)
at androidx.room.testing.MigrationTestHelper.createDatabase(MigrationTestHelper.java:152)
at globalTests.migrations.MigrationTest.migrate1To2(MigrationTest.java:31)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:61)
at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
at org.robolectric.RobolectricTestRunner$HelperTestRunner$1.evaluate(RobolectricTestRunner.java:575)
at org.robolectric.internal.SandboxTestRunner$2.lambda$evaluate$0(SandboxTestRunner.java:263)
at org.robolectric.internal.bytecode.Sandbox.lambda$runOnMainThread$0(Sandbox.java:89)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
In test structure:
MigrationTest :
package globalTests.migrations;
import ...;
#RunWith(AndroidJUnit4.class)
public class MigrationTest {
private static final String TEST_DB = "migration-test";
#Rule
public MigrationTestHelper helper;
public MigrationTest() {
helper = new MigrationTestHelper(InstrumentationRegistry.getInstrumentation(),
Sauvegarde.class.getCanonicalName(),
new FrameworkSQLiteOpenHelperFactory());
}
#Test
public void migrate1To2() throws IOException {
SupportSQLiteDatabase db = helper.createDatabase(TEST_DB, 1);
// Prepare for the next version.
db.close();
// Re-open the database with version 2 and provide
// MIGRATION_1_2 as the migration process.
db = helper.runMigrationsAndValidate(TEST_DB, 2, true, Migrations.MIGRATION_1_2);
// MigrationTestHelper automatically verifies the schema changes,
// but you need to validate that the data was migrated properly.
}
}
gradle.build :
testOptions {
execution 'ANDROIDX_TEST_ORCHESTRATOR'
}
javaCompileOptions {
annotationProcessorOptions {
arguments += ["room.schemaLocation":
"$projectDir/schemas".toString()]
}
}
sourceSets {
// Adds exported schema location as test app assets.
debug.assets.srcDirs += files("$projectDir/schemas".toString())
customDebugType.assets.srcDirs += files("$projectDir/schemas".toString())
androidTest.assets.srcDirs += files("$projectDir/schemas".toString())
test.assets.srcDirs += files("$projectDir/schemas".toString())
}
In schemas location :
The problem is like this one, but the solution not worked for me ...

Answer 1

Speaking from experience, one possible source of this issue is the stripping of assets during packaging, i.e., if you have something like the rule below. It seems like it should apply to the release build only, but, alas, it applies do debug as well and will remove your schema files from view.
buildTypes {
debug {...}
release {
aaptOptions {
ignoreAssetsPattern '!*.json'
}
}
}
Something else you could do is to look at what assets are visible to the various contexts you have available to you in the test itself:
println("Instrumentation context.assets")
var assets = InstrumentationRegistry.getInstrumentation().context.assets
assets.list("")?.forEachIndexed { index, it ->
println("$index -> $it")
}
println("Instrumentation targetContext.assets")
assets = InstrumentationRegistry.getInstrumentation().targetContext.assets
assets.list("")?.forEachIndexed { index, it ->
println("$index -> $it")
}
println("ApplicationProvider context.assets")
assets = ApplicationProvider.getApplicationContext<App>().assets
assets.list("")?.forEachIndexed { index, it ->
println("$index -> $it")
}

Answer 2

I found the problem,
Roboelectric didn't import my Android resources for the tests
you need to add this to Gradle:
testOptions {
unitTests{
includeAndroidResources = true
}
}
Source