Android 仪器测试在测试使用 RoomDatabase.withTransaction 的挂起函数时冻结

我正在尝试测试以下 LocalDataSource 函数，NameLocalData.methodThatFreezes功能，但它冻结了。我该如何解决这个问题？或者我怎样才能以另一种方式测试它？

待测试类

class NameLocalData(private val roomDatabase: RoomDatabase) : NameLocalDataSource {

  override suspend fun methodThatFreezes(someParameter: Something): Something {
    roomDatabase.withTransaction {
      try {
        // calling room DAO methods here
      } catch(e: SQLiteConstraintException) {
        // ...
      }
      return something
    }
  }
}

测试班

@MediumTest
@RunWith(AndroidJUnit4::class)
class NameLocalDataTest {
  private lateinit var nameLocalData: NameLocalData

  // creates a Room database in memory
  @get:Rule
  var roomDatabaseRule = RoomDatabaseRule()

  @get:Rule
  var instantTaskExecutorRule = InstantTaskExecutorRule()

  @Before
  fun setup() = runBlockingTest {
     initializesSomeData()
     nameLocalData = NameLocalData(roomDatabaseRule.db)
  }

 @Test
 fun methodThatFreezes() = runBlockingTest {
    nameLocalData.methodThatFreezes // test freezes
 }

 // ... others NameLocalDataTest tests where those functions been tested does not use
 // roomDatabase.withTransaction { } 
}

Gradle 的文件配置

espresso_version = '3.2.0'
kotlin_coroutines_version = '1.3.3'
room_version = '2.2.5'

test_arch_core_testing = '2.1.0'
test_ext_junit_version = '1.1.1'
test_roboletric = '4.3.1'
test_runner_version = '1.2.0'

androidTestImplementation "androidx.arch.core:core-testing:$test_arch_core_testing"
androidTestImplementation "androidx.test.espresso:espresso-core:$espresso_version"
androidTestImplementation "androidx.test.ext:junit:$test_ext_junit_version"
androidTestImplementation "androidx.test:rules:$test_runner_version"
androidTestImplementation "androidx.test:runner:$test_runner_version"
androidTestImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:$kotlin_coroutines_version"

上次我为 Room 数据库编写了一个测试，我只是简单地使用runBlock这对我有用...... 你能看一下吗这个样本 https://github.com/nglauber/books_jetpack/blob/master/data_room/src/androidTest/java/dominando/android/data_room/RoomRepositoryTest.kt并检查它是否也适合您？

编辑： 行动！我错过了这一部分...我尝试了这个（在同一个示例中）：

1. 我在 DAO 中定义了一个虚拟函数@Transaction

@Transaction
suspend fun quickInsert(book: Book) {
    save(book)
    delete(book)
}

2. 我认为这是问题的关键。添加setTransactionExecutor到您的数据库实例化。

appDatabase = Room.inMemoryDatabaseBuilder(
    InstrumentationRegistry.getInstrumentation().context,
    AppDatabase::class.java
).setTransactionExecutor(Executors.newSingleThreadExecutor())
    .build()

3. 最后，测试使用runBlocking

@Test
fun dummyTest() = runBlocking {
    val dao = appDatabase.bookDao();
    val id = dummyBook.id

    dao.quickInsert(dummyBook)

    val book = dao.bookById(id).first()
    assertNull(book)
}

See 这个问题 https://stackoverflow.com/questions/56380210/android-instrumentation-test-doesnt-run-to-end-when-using-room-transaction-fun.