How to use the inMemory() setting?

Zsolt_Bertalan · May 26, 2023, 12:08pm

When I try to use the inMemory() setting, I run into various problems.

Roughly it looks like this:

RealmConfiguration.Builder(
schema = setOf(
…RealmObject declarations
)
).inMemory().build()

In Unit tests it causes an ExceptionInInitializerError with NullPointerException.
In Robolectric or Instrumentation tests it causes the following:
kotlin.UninitializedPropertyAccessException: lateinit property filesDir has not been initialized.

What am I doing wrong?

Claus_Rorbech · May 26, 2023, 12:38pm

The issue is that Android unittests are running in a non-Android JVM environment, but the infrastructure in AGP is pulling in Android dependencies for the test. The dependencies are not properly initialized when not running on an device/emulator.

We are in the process of migrating to the new Android source set layout from Kotlin 1.8 and you can track the progress in Migrate to new Android source sets for tests introduced in Kotlin 1.8 by cmelchior · Pull Request #1399 · realm/realm-kotlin · GitHub.

Until that you will have to run Android tests (both unit tests and device test) on a device/emulator.

Zsolt_Bertalan · May 26, 2023, 1:18pm

That’s what I’m trying to do. That’s where I got the second exception.

Zsolt_Bertalan · May 26, 2023, 1:25pm

I’m working on an Android only project, so the ticket is not relevant to me, I think.

Claus_Rorbech · May 26, 2023, 1:41pm

Hmm, okay. Then it might be that our initializer, that picks up the context, just isn’t triggered correctly. We use the App Startup infrastruture as described in App Startup | Android Developers for that. Might be that Robolectric has an initializer that is running before ours. Would you be able to inspect the app manifest to see if Robolectric involves any initializers (App Startup | Android Developers). If so then we might be able to control the ordering of them by providing a custom initializer that depends on both.

Zsolt_Bertalan · May 26, 2023, 2:46pm

That makes sense now, because we use Initializers, and when I set up the project, I had to add RealmInitializer as a dependency for a few Initializers to make it work and remove the very same error message with the filesDir.
However, now I run into this in normal Ui tests as well, even when I turn HiltAndroidRule off. Do I need to pass context somehow in tests?

Zsolt_Bertalan · May 26, 2023, 3:04pm

I think I solved it. We still used (even with Hilt off) a custom AndroidJUnitRunner with a custom Application. I added RealmInitializer to this like this:

        val appInitializer = AppInitializer.getInstance(this)
        appInitializer.initializeComponent(RealmInitializer::class.java)

And it works! Thanks.

Claus_Rorbech · May 26, 2023, 3:21pm

Great to hear.

… Claus

Zsolt_Bertalan · June 7, 2023, 4:10pm

My last comment above solved the problems with Instrumentation tests. Now as the last part of our migration, I delete SQLite DataSources and convert their Robolectric integration Unit tests to target the Realm DataSources.
However, I run into a similar problem as before. Here is the stack trace:

com.getkeepsafe.relinker.MissingLibraryException: Could not find 'librealmc.dylib'. Looked for: [armeabi-v7a], but only found: [].
androidx.startup.StartupException: com.getkeepsafe.relinker.MissingLibraryException: Could not find 'librealmc.dylib'. Looked for: [armeabi-v7a], but only found: [].
	at androidx.startup.AppInitializer.doInitialize(AppInitializer.java:187)
	at androidx.startup.AppInitializer.doInitialize(AppInitializer.java:138)
	at androidx.startup.AppInitializer.initializeComponent(AppInitializer.java:117)
	at com.reachplc.data.news.InstrumentationTestApp.onCreate(InstrumentationTestApp.kt:15)
	at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1154)
	at org.robolectric.android.internal.RoboMonitoringInstrumentation.callApplicationOnCreate(RoboMonitoringInstrumentation.java:127)
	at org.robolectric.android.internal.AndroidTestEnvironment.lambda$installAndCreateApplication$2(AndroidTestEnvironment.java:368)
	at app//org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:86)
	at org.robolectric.android.internal.AndroidTestEnvironment.installAndCreateApplication(AndroidTestEnvironment.java:366)
	at org.robolectric.android.internal.AndroidTestEnvironment.lambda$createApplicationSupplier$0(AndroidTestEnvironment.java:245)
	at app//org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:53)
	at org.robolectric.android.internal.AndroidTestEnvironment.lambda$createApplicationSupplier$1(AndroidTestEnvironment.java:242)
	at com.google.common.base.Suppliers$NonSerializableMemoizingSupplier.get(Suppliers.java:183)
	at org.robolectric.RuntimeEnvironment.getApplication(RuntimeEnvironment.java:72)
	at org.robolectric.android.internal.AndroidTestEnvironment.setUpApplicationState(AndroidTestEnvironment.java:210)
	at app//org.robolectric.RobolectricTestRunner.beforeTest(RobolectricTestRunner.java:331)
	at app//org.robolectric.internal.SandboxTestRunner$2.lambda$evaluate$2(SandboxTestRunner.java:278)
	at app//org.robolectric.internal.bytecode.Sandbox.lambda$runOnMainThread$0(Sandbox.java:99)
	at java.base@17.0.5/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base@17.0.5/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base@17.0.5/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base@17.0.5/java.lang.Thread.run(Thread.java:833)
Caused by: com.getkeepsafe.relinker.MissingLibraryException: Could not find 'librealmc.dylib'. Looked for: [armeabi-v7a], but only found: [].
	at com.getkeepsafe.relinker.ApkLibraryInstaller.installLibrary(ApkLibraryInstaller.java:175)
	at com.getkeepsafe.relinker.ReLinkerInstance.loadLibraryInternal(ReLinkerInstance.java:180)
	at com.getkeepsafe.relinker.ReLinkerInstance.loadLibrary(ReLinkerInstance.java:136)
	at com.getkeepsafe.relinker.ReLinker.loadLibrary(ReLinker.java:70)
	at com.getkeepsafe.relinker.ReLinker.loadLibrary(ReLinker.java:57)
	at io.realm.kotlin.internal.AndroidUtilsKt.loadAndroidNativeLibs(AndroidUtils.kt:14)
	at io.realm.kotlin.internal.RealmInitializer.create(RealmInitializer.kt:42)
	at io.realm.kotlin.internal.RealmInitializer.create(RealmInitializer.kt:30)
	at androidx.startup.AppInitializer.doInitialize(AppInitializer.java:180)
	at androidx.startup.AppInitializer.doInitialize(AppInitializer.java:138)
	at androidx.startup.AppInitializer.initializeComponent(AppInitializer.java:117)
	at com.reachplc.data.news.InstrumentationTestApp.onCreate(InstrumentationTestApp.kt:15)
	at android.app.Instrumentation.$$robo$$android_app_Instrumentation$callApplicationOnCreate(Instrumentation.java:1154)
	at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java)
	... 17 more

Important to note, that we have normal Unit tests with mocked Realm, but these are integration tests with in-memory Realm.
I found some related questions on the internet, but they are mostly old and probably outdated. I found this ticket too, which is outstanding, but this is for realm-java, and it seems there is no more blockers to add Robolectric support:

github.com/realm/realm-java

Add support for Robolectric

opened 05:10PM - 24 Feb 15 UTC

vvictor10

T-Feature O-Community

Referring to: https://github.com/robolectric/robolectric/issues/1389 Can we ple…ase get an update on this issue. We have tons of integration test we need to run outside of an emulator/device and roboelectric is the only way for us to shadow the Android classes. Without the required support on Realm, we are pretty much blocked before we make the move over from DB4O to Realm. The other two major sticking points are support for null and the lack of a high level API list for performing migrations. Thanks a lot for the support.

So ultimately the question is: is Robolectric supported for in-memory Realm for realm-kotlin?