I trying to add a type converter for my entity, which presented below:

@Entity(tableName = "wall_items_table")
data class WallItemEntity(
    @PrimaryKey(autoGenerate = true)
    val databaseId: Int = 0,
    val attachments: List<Attachment>,
    val likes: Likes
)

in hilt module, which provides database:

@Module
@InstallIn(SingletonComponent::class)
internal object DatabaseModule {

    @Singleton
    @Provides
    fun provideDatabase(
        @ApplicationContext context: Context,
        likesConverter: LikesConverter,
        attachmentsConverter: AttachmentsConverter
    ): VkFriendsApplicationDatabase {
        return Room.databaseBuilder(
            context = context,
            klass = VkFriendsApplicationDatabase::class.java,
            name = "vkFriendsApplicationDatabase.db"
        )
            .addTypeConverter(likesConverter)
            .addTypeConverter(attachmentsConverter)
            .build()
    }

}

But room still don’t see converters, and throws the error: Cannot figure out how to save this field into database. You can consider adding a type converter for it.

Here is my abstract class BaseConverter<T>, which represents base logic for all converters:

abstract class BaseConverter<T> {

    protected abstract val jsonAdapter: JsonAdapter<T>

    @TypeConverter
    fun toJson(data: T?): String {
        return try {
            data?.let { jsonAdapter.toJson(it) } ?: ""
        } catch (e: IOException) {
            ""
        }
    }

    @TypeConverter
    fun fromJson(json: String): T? {
        return try {
            jsonAdapter.fromJson(json)
        } catch (e: IOException) {
            null
        }
    }

}

Implementations. I tried to remove abstract class and put functions annotated by TypeConverter directly to these classes, but it whatever not works

@ProvidedTypeConverter
class LikesConverter @Inject constructor(
    override val jsonAdapter: JsonAdapter<Likes>
) : BaseConverter<Likes>()

@ProvidedTypeConverter
class AttachmentsConverter @Inject constructor(
    override val jsonAdapter: JsonAdapter<List<Attachment>>
) : BaseConverter<List<Attachment>>()

And database:

@Database(
    entities = [
        FriendEntity::class,
        UserEntity::class,
        WallItemEntity::class
    ],
    version = 1
)
internal abstract class VkFriendsApplicationDatabase : RoomDatabase() {
    abstract val friendsDao: FriendsDao
    abstract val usersDao: UsersDao
}