cannot find implementation for com.application.unittest.data.local.ShoppingItemDatabase. ShoppingIte-CodePudding

I have a problem with Room test I have checked all stackoverflow solutions, but nothing works for me. I'm so beginner at test. I tried a lot of solution like change kapt and add other libraries for room

This is the Error:

java.lang.RuntimeException: cannot find implementation for com.application.unittest.data.local.ShoppingItemDatabase. ShoppingItemDatabase_Impl does not exist
at androidx.room.Room.getGeneratedImplementation(Room.java:100)
at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1486)
at com.application.unittest.data.local.ShoppingDaoTest.setup(ShoppingDaoTest.kt:40)

this is my DB class:

@Database(entities = [ShoppingItem::class], version = 1)
abstract class ShoppingItemDatabase:RoomDatabase() {
    abstract fun shoppingDao():ShoppingDao
}

This is the interface:

@Dao
interface ShoppingDao {

    @Insert(onConflict = OnConflictStrategy.REPLACE)
    suspend fun insertShoppingItem(shoppingItem: ShoppingItem)

    @Delete
    suspend fun deleteShoppingItem(shoppingItem: ShoppingItem)

    @Query("SELECT * FROM shopping_items")
    fun observeAllShoppingItems():LiveData<List<ShoppingItem>>

    @Query("SELECT SUM(price * amount) FROM shopping_items")
    fun observeTotalPrice():LiveData<Float>
}

This is the Test:

@ExperimentalCoroutinesApi
@RunWith(AndroidJUnit4::class)
@SmallTest
class ShoppingDaoTest {

    @get:Rule
    var instantTaskExecutorRule = InstantTaskExecutorRule()

    private lateinit var database: ShoppingItemDatabase
    private lateinit var dao: ShoppingDao

    @Before
    fun setup(){

            database = Room.inMemoryDatabaseBuilder(
                ApplicationProvider.getApplicationContext(),
                ShoppingItemDatabase::class.java
            )
                .allowMainThreadQueries()
                .build()
            dao = database.shoppingDao()

    }

    @After
    fun teardown(){
        database.close()
    }

    @Test
    fun insertShoppingItem() = runTest {
        val shoppingItem = ShoppingItem(id = 1,"name",1,2f,"image")
        dao.insertShoppingItem(shoppingItem)

        val allShoppingItems = dao.observeAllShoppingItems().getOrAwaitValue()

        assertThat(allShoppingItems).contains(shoppingItem)
    }

}

So what should I do?

CodePudding user response：

Do you have an application class to instantiate the room database?

if so make sure your android manifest has this line of code under application.

<application android:name="com.application.unittest.(then you application class name)"

CodePudding user response：

The app I built recently had the same error as yours but it worked after I put the application name in the manifest. I was not using TDD or Hilt though so I am not sure if this will work or not.

But the application class I used contained this:

class MyApplication: Application() {

val database: your database class by lazy { your database class).getDatabase(this) }

}

Then make sure the application name is in the manifest. I hope this helps.