Fix network requests sometimes returning null instead of either ret…

…urning success or failure

CHANGELOG.md

@@ -9,6 +9,7 @@
 ### Fixed
 * Realm objects accessors behave as an unmanaged object after an incremental build. (Issue [#7844](https://github.com/realm/realm-java/pull/7844))
 * [RealmApp] Crash when opening a Realm with a proxy enabled. (Issue [#7828](https://github.com/realm/realm-java/issues/7828))
+* [RealmApp] It was possible to create a `User` object with invalid state that would throw a `NullPointerException` when accessed. (Issue [#7847](https://github.com/realm/realm-java/issues/7847))
 
 ### Compatibility
 * File format: Generates Realms with format v23. Unsynced Realms will be upgraded from Realm Java 2.0 and later. Synced Realms can only be read and upgraded if created with Realm Java v10.0.0-BETA.1.

realm/realm-library/src/androidTestObjectServer/kotlin/io/realm/internal/network/NetworkRequestTests.kt

@@ -0,0 +1,41 @@
+package io.realm.internal.network
+
+import androidx.test.platform.app.InstrumentationRegistry
+import io.realm.Realm
+import io.realm.mongodb.App
+import io.realm.mongodb.AppException
+import io.realm.mongodb.ErrorCode
+import junit.framework.TestCase.assertEquals
+import org.junit.Before
+import org.junit.Test
+import kotlin.test.assertFailsWith
+
+class NetworkRequestTests {
+
+ private lateinit var app: App
+
+ @Before
+ fun setUp() {
+ Realm.init(InstrumentationRegistry.getInstrumentation().targetContext)
+ }
+
+ // Test for https://github.com/realm/realm-java/issues/7847
+ @Test
+ fun interruptedRequestReturnsError() {
+ val request = object: NetworkRequest<Unit>() {
+ override fun mapSuccess(result: Any?): Unit {
+ Unit
+ }
+
+ override fun execute(callback: NetworkRequest<Unit>) {
+ Thread.currentThread().interrupt()
+ }
+ }
+ assertFailsWith<AppException> {
+ request.resultOrThrow()
+ }.also {
+ assertEquals(it.errorCode, ErrorCode.NETWORK_INTERRUPTED)
+ assertEquals(it.errorMessage, "Network request interrupted.")
+ }
+ }
+}

realm/realm-library/src/objectServer/java/io/realm/internal/network/NetworkRequest.java

@@ -48,9 +48,7 @@ public abstract class NetworkRequest<T> extends OsJavaNetworkTransport.NetworkTr
  @Override
  public void onSuccess(Object result) {
  T mappedResult = mapSuccess(result);
- if (success != null) {
- success.set(mappedResult);
- }
+ success.set(mappedResult);
  latch.countDown();
  }
 
@@ -87,23 +85,19 @@ public T resultOrThrow() {
 
  execute(this);
  try {
- // Wait indefinitely. Timeouts should be handled by the Network layer,
- // so will eventually bubble up as an exception.
+ // Wait indefinitely. Timeouts should be handled by the Network layer, otherwise
+ // it can be interrupted manually by calling `RealmAsyncTask.cancel()`
  latch.await();
  } catch (InterruptedException e) {
- RealmLog.debug("Network request interrupted.");
+ error.set(new AppException(ErrorCode.NETWORK_INTERRUPTED, "Network request interrupted."));
  }
 
  // Result of request should be available. Throw if an error happened, otherwise return
  // the result.
  if (error.get() != null) {
  throw error.get();
  } else {
- if (success != null) {
- return success.get();
- } else {
- return null;
- }
+ return success.get();
  }
  }
 }

realm/realm-library/src/objectServer/java/io/realm/internal/network/VoidNetworkRequest.java

@@ -11,7 +11,7 @@
 
 /**
  * Specialized case of {@link NetworkRequest} where we are not interested in the response value,
- * just wether or not the request succeeded.
+ * just whether or not the request succeeded.
  */
 public abstract class VoidNetworkRequest extends NetworkRequest<Void> {