With lazy loading of contributions (#3566)

app/src/test/kotlin/fr/free/nrw/commons/contributions/ContributionBoundaryCallbackTest.kt

@@ -0,0 +1,139 @@
+package fr.free.nrw.commons.contributions
+
+import android.content.Context
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import com.nhaarman.mockitokotlin2.*
+import fr.free.nrw.commons.Media
+import fr.free.nrw.commons.auth.SessionManager
+import fr.free.nrw.commons.media.MediaClient
+import fr.free.nrw.commons.utils.NetworkUtilsTest
+import fr.free.nrw.commons.utils.createMockDataSourceFactory
+import io.reactivex.Scheduler
+import io.reactivex.Single
+import io.reactivex.schedulers.Schedulers
+import io.reactivex.schedulers.TestScheduler
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.mockito.ArgumentMatchers.*
+import org.mockito.InjectMocks
+import org.mockito.Mock
+import org.mockito.Mockito.mock
+import org.mockito.MockitoAnnotations
+import java.lang.RuntimeException
+import java.util.*
+
+/**
+ * The unit test class for ContributionBoundaryCallbackTest
+ */
+class ContributionBoundaryCallbackTest {
+    @Mock
+    internal lateinit var repository: ContributionsRepository
+
+    @Mock
+    internal lateinit var sessionManager: SessionManager
+
+    @Mock
+    internal lateinit var mediaClient: MediaClient
+
+    private lateinit var contributionBoundaryCallback: ContributionBoundaryCallback
+
+    @Rule
+    @JvmField
+    var instantTaskExecutorRule = InstantTaskExecutorRule()
+
+    lateinit var scheduler: Scheduler
+
+    /**
+     * initial setup
+     */
+    @Before
+    @Throws(Exception::class)
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+        scheduler = Schedulers.trampoline()
+        contributionBoundaryCallback =
+            ContributionBoundaryCallback(repository, sessionManager, mediaClient, scheduler);
+    }
+
+    @Test
+    fun testOnZeroItemsLoaded() {
+        whenever(repository.save(anyList<Contribution>()))
+            .thenReturn(Single.just(listOf(1L, 2L)))
+        whenever(sessionManager.userName).thenReturn("Test")
+        whenever(mediaClient.getMediaListForUser(anyString())).thenReturn(
+            Single.just(listOf(mock(Media::class.java)))
+        )
+        whenever(mediaClient.doesMediaListForUserHaveMorePages(anyString()))
+            .thenReturn(true)
+        contributionBoundaryCallback.onZeroItemsLoaded()
+        verify(repository).save(anyList<Contribution>());
+        verify(mediaClient).getMediaListForUser(anyString());
+    }
+
+    @Test
+    fun testOnLastItemLoaded() {
+        whenever(repository.save(anyList<Contribution>()))
+            .thenReturn(Single.just(listOf(1L, 2L)))
+        whenever(sessionManager.userName).thenReturn("Test")
+        whenever(mediaClient.getMediaListForUser(anyString())).thenReturn(
+            Single.just(listOf(mock(Media::class.java)))
+        )
+        whenever(mediaClient.doesMediaListForUserHaveMorePages(anyString()))
+            .thenReturn(true)
+        contributionBoundaryCallback.onItemAtEndLoaded(mock(Contribution::class.java))
+        verify(repository).save(anyList());
+        verify(mediaClient).getMediaListForUser(anyString());
+    }
+
+    @Test
+    fun testOnFrontItemLoaded() {
+        whenever(repository.save(anyList<Contribution>()))
+            .thenReturn(Single.just(listOf(1L, 2L)))
+        whenever(sessionManager.userName).thenReturn("Test")
+        whenever(mediaClient.getMediaListForUser(anyString())).thenReturn(
+            Single.just(listOf(mock(Media::class.java)))
+        )
+        whenever(mediaClient.doesMediaListForUserHaveMorePages(anyString()))
+            .thenReturn(true)
+        contributionBoundaryCallback.onItemAtFrontLoaded(mock(Contribution::class.java))
+        verify(repository).save(anyList());
+        verify(mediaClient).getMediaListForUser(anyString());
+    }
+
+    @Test
+    fun testFetchContributions() {
+        whenever(repository.save(anyList<Contribution>()))
+            .thenReturn(Single.just(listOf(1L, 2L)))
+        whenever(sessionManager.userName).thenReturn("Test")
+        whenever(mediaClient.getMediaListForUser(anyString())).thenReturn(
+            Single.just(listOf(mock(Media::class.java)))
+        )
+        whenever(mediaClient.doesMediaListForUserHaveMorePages(anyString()))
+            .thenReturn(true)
+        contributionBoundaryCallback.fetchContributions()
+        verify(repository).save(anyList());
+        verify(mediaClient).getMediaListForUser(anyString());
+    }
+
+    @Test
+    fun testFetchContributionsForEndOfList() {
+        whenever(sessionManager.userName).thenReturn("Test")
+        whenever(mediaClient.doesMediaListForUserHaveMorePages(anyString()))
+            .thenReturn(false)
+        contributionBoundaryCallback.fetchContributions()
+        verify(mediaClient, times(0)).getMediaListForUser(anyString())
+        verifyNoMoreInteractions(repository)
+    }
+
+    @Test
+    fun testFetchContributionsFailed() {
+        whenever(sessionManager.userName).thenReturn("Test")
+        whenever(mediaClient.doesMediaListForUserHaveMorePages(anyString()))
+            .thenReturn(true)
+        whenever(mediaClient.getMediaListForUser(anyString())).thenReturn(Single.error(Exception("Error")))
+        contributionBoundaryCallback.fetchContributions()
+        verifyZeroInteractions(repository);
+        verify(mediaClient).getMediaListForUser(anyString());
+    }
+}

app/src/test/kotlin/fr/free/nrw/commons/contributions/ContributionsListPresenterTest.kt

@@ -0,0 +1,63 @@
+package fr.free.nrw.commons.contributions
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import com.nhaarman.mockitokotlin2.times
+import com.nhaarman.mockitokotlin2.verify
+import com.nhaarman.mockitokotlin2.verifyZeroInteractions
+import com.nhaarman.mockitokotlin2.whenever
+import fr.free.nrw.commons.Media
+import fr.free.nrw.commons.auth.SessionManager
+import fr.free.nrw.commons.media.MediaClient
+import io.reactivex.Completable
+import io.reactivex.Scheduler
+import io.reactivex.Single
+import io.reactivex.schedulers.Schedulers
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.mockito.ArgumentMatchers
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mock
+import org.mockito.Mockito
+import org.mockito.Mockito.mock
+import org.mockito.MockitoAnnotations
+
+/**
+ * The unit test class for ContributionsListPresenterTest
+ */
+class ContributionsListPresenterTest {
+    @Mock
+    internal lateinit var contributionBoundaryCallback: ContributionBoundaryCallback
+
+    @Mock
+    internal lateinit var repository: ContributionsRepository
+
+    @Rule
+    @JvmField
+    var instantTaskExecutorRule = InstantTaskExecutorRule()
+
+    lateinit var scheduler: Scheduler
+
+    lateinit var contributionsListPresenter: ContributionsListPresenter
+
+    /**
+     * initial setup
+     */
+    @Before
+    @Throws(Exception::class)
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+        scheduler = Schedulers.trampoline()
+        contributionsListPresenter =
+            ContributionsListPresenter(contributionBoundaryCallback, repository, scheduler);
+    }
+
+    @Test
+    fun testDeleteUpload() {
+        whenever(repository.deleteContributionFromDB(any<Contribution>()))
+            .thenReturn(Completable.complete())
+        contributionsListPresenter.deleteUpload(mock(Contribution::class.java))
+        verify(repository, times(1))
+            .deleteContributionFromDB(ArgumentMatchers.any(Contribution::class.java));
+    }
+}

app/src/test/kotlin/fr/free/nrw/commons/contributions/ContributionsPresenterTest.kt

@@ -7,9 +7,11 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.loader.content.CursorLoader
 import androidx.loader.content.Loader
+import com.nhaarman.mockitokotlin2.any
 import com.nhaarman.mockitokotlin2.mock
 import com.nhaarman.mockitokotlin2.verify
 import com.nhaarman.mockitokotlin2.whenever
+import io.reactivex.Completable
 import io.reactivex.Scheduler
 import io.reactivex.Single
 import io.reactivex.schedulers.TestScheduler
@@ -17,9 +19,11 @@ import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 import org.mockito.ArgumentMatchers
+import org.mockito.ArgumentMatchers.*
 import org.mockito.Mock
 import org.mockito.Mockito
 import org.mockito.MockitoAnnotations
+import java.util.concurrent.TimeUnit
 
 /**
  * The unit test class for ContributionsPresenter
@@ -42,7 +46,7 @@ class ContributionsPresenterTest {
 
     @Rule @JvmField var instantTaskExecutorRule = InstantTaskExecutorRule()
 
-    lateinit var scheduler : Scheduler
+    lateinit var scheduler : TestScheduler
 
     /**
      * initial setup
@@ -60,23 +64,13 @@ class ContributionsPresenterTest {
         liveData=MutableLiveData()
     }
 
-    /**
-     * Test fetch contributions
-     */
-    @Test
-    fun testFetchContributions(){
-        whenever(repository.getString(ArgumentMatchers.anyString())).thenReturn("10")
-        whenever(repository.fetchContributions()).thenReturn(liveData)
-        contributionsPresenter.fetchContributions()
-        verify(repository).fetchContributions()
-    }
-
     /**
      * Test presenter actions onDeleteContribution
      */
     @Test
     fun testDeleteContribution() {
-        whenever(repository.deleteContributionFromDB(ArgumentMatchers.any(Contribution::class.java))).thenReturn(Single.just(1))
+        whenever(repository.deleteContributionFromDB(ArgumentMatchers.any<Contribution>()))
+            .thenReturn(Completable.complete())
         contributionsPresenter.deleteUpload(contribution)
         verify(repository).deleteContributionFromDB(contribution)
     }

app/src/test/kotlin/fr/free/nrw/commons/contributions/ContributionsRepositoryTest.kt

@@ -0,0 +1,55 @@
+package fr.free.nrw.commons.contributions
+
+import com.nhaarman.mockitokotlin2.times
+import com.nhaarman.mockitokotlin2.verify
+import com.nhaarman.mockitokotlin2.whenever
+import fr.free.nrw.commons.utils.createMockDataSourceFactory
+import io.reactivex.Scheduler
+import io.reactivex.Single
+import junit.framework.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import org.mockito.*
+import org.mockito.Mockito.any
+import org.mockito.Mockito.mock
+
+/**
+ * The unit test class for ContributionsRepositoryTest
+ */
+class ContributionsRepositoryTest {
+    @Mock
+    internal lateinit var localDataSource: ContributionsLocalDataSource
+
+    @InjectMocks
+    private lateinit var contributionsRepository: ContributionsRepository
+
+    lateinit var scheduler: Scheduler
+
+    /**
+     * initial setup
+     */
+    @Before
+    @Throws(Exception::class)
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+    }
+
+    @Test
+    fun testFetchContributions() {
+        val contribution = mock(Contribution::class.java)
+        whenever(localDataSource.getContributions())
+            .thenReturn(createMockDataSourceFactory(listOf(contribution)))
+        val contributionsFactory = contributionsRepository.fetchContributions()
+        verify(localDataSource, times(1)).getContributions();
+    }
+
+    @Test
+    fun testSaveContribution() {
+        val contributions = listOf(mock(Contribution::class.java))
+        whenever(localDataSource.saveContributions(ArgumentMatchers.anyList()))
+            .thenReturn(Single.just(listOf(1L)))
+        val save = contributionsRepository.save(contributions).test().assertValueAt(0) {
+            it.size == 1 && it.get(0) == 1L
+        }
+    }
+}

app/src/test/kotlin/fr/free/nrw/commons/media/MediaClientTest.kt

@@ -1,5 +1,6 @@
 package fr.free.nrw.commons.media
 
+import com.nhaarman.mockitokotlin2.whenever
 import fr.free.nrw.commons.Media
 import fr.free.nrw.commons.utils.CommonsDateUtil
 import io.reactivex.Observable
@@ -7,18 +8,16 @@ import junit.framework.Assert.*
 import org.junit.Before
 import org.junit.Test
 import org.mockito.*
-import org.mockito.Mockito.`when`
-import org.mockito.Mockito.mock
 import org.wikipedia.dataclient.mwapi.ImageDetails
 import org.wikipedia.dataclient.mwapi.MwQueryPage
 import org.wikipedia.dataclient.mwapi.MwQueryResponse
 import org.wikipedia.dataclient.mwapi.MwQueryResult
 import org.wikipedia.gallery.ImageInfo
 import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.*
 import java.util.*
 import org.mockito.Captor
-
-
+import org.mockito.Mockito.*
 
 
 class MediaClientTest {
@@ -46,9 +45,10 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.checkPageExistsUsingTitle(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
-        val checkPageExistsUsingTitle = mediaClient!!.checkPageExistsUsingTitle("File:Test.jpg").blockingGet()
+        val checkPageExistsUsingTitle =
+            mediaClient!!.checkPageExistsUsingTitle("File:Test.jpg").blockingGet()
         assertTrue(checkPageExistsUsingTitle)
     }
 
@@ -63,9 +63,10 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.checkPageExistsUsingTitle(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
-        val checkPageExistsUsingTitle = mediaClient!!.checkPageExistsUsingTitle("File:Test.jpg").blockingGet()
+        val checkPageExistsUsingTitle =
+            mediaClient!!.checkPageExistsUsingTitle("File:Test.jpg").blockingGet()
         assertFalse(checkPageExistsUsingTitle)
     }
 
@@ -80,7 +81,7 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.checkFileExistsUsingSha(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         val checkFileExistsUsingSha = mediaClient!!.checkFileExistsUsingSha("abcde").blockingGet()
         assertTrue(checkFileExistsUsingSha)
@@ -97,7 +98,7 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.checkFileExistsUsingSha(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         val checkFileExistsUsingSha = mediaClient!!.checkFileExistsUsingSha("abcde").blockingGet()
         assertFalse(checkFileExistsUsingSha)
@@ -117,7 +118,7 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.getMedia(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         assertEquals("Test", mediaClient!!.getMedia("abcde").blockingGet().filename)
     }
@@ -136,10 +137,11 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.getMedia(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         assertEquals(Media.EMPTY, mediaClient!!.getMedia("abcde").blockingGet())
     }
+
     @Captor
     private val filenameCaptor: ArgumentCaptor<String>? = null
 
@@ -159,18 +161,18 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
 
         `when`(mediaInterface!!.getMediaWithGenerator(filenameCaptor!!.capture()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         assertEquals("Test", mediaClient!!.getPictureOfTheDay().blockingGet().filename)
         assertEquals(template, filenameCaptor.value);
     }
-  
+
     @Captor
     private val continuationCaptor: ArgumentCaptor<Map<String, String>>? = null
 
     @Test
     fun getMediaListFromCategoryTwice() {
-        val mockContinuation= mapOf(Pair("gcmcontinue", "test"))
+        val mockContinuation = mapOf(Pair("gcmcontinue", "test"))
         val imageInfo = ImageInfo()
 
         val mwQueryPage = mock(MwQueryPage::class.java)
@@ -184,9 +186,13 @@ class MediaClientTest {
         `when`(mockResponse.query()).thenReturn(mwQueryResult)
         `when`(mockResponse.continuation()).thenReturn(mockContinuation)
 
-        `when`(mediaInterface!!.getMediaListFromCategory(ArgumentMatchers.anyString(), ArgumentMatchers.anyInt(),
-                continuationCaptor!!.capture()))
-                .thenReturn(Observable.just(mockResponse))
+        `when`(
+            mediaInterface!!.getMediaListFromCategory(
+                ArgumentMatchers.anyString(), ArgumentMatchers.anyInt(),
+                continuationCaptor!!.capture()
+            )
+        )
+            .thenReturn(Observable.just(mockResponse))
         val media1 = mediaClient!!.getMediaListFromCategory("abcde").blockingGet().get(0)
         val media2 = mediaClient!!.getMediaListFromCategory("abcde").blockingGet().get(0)
 
@@ -197,6 +203,38 @@ class MediaClientTest {
         assertEquals(media2.filename, "Test")
     }
 
+    @Test
+    fun getMediaListForUser() {
+        val mockContinuation = mapOf("gcmcontinue" to "test")
+        val imageInfo = ImageInfo()
+
+        val mwQueryPage = mock(MwQueryPage::class.java)
+        whenever(mwQueryPage.title()).thenReturn("Test")
+        whenever(mwQueryPage.imageInfo()).thenReturn(imageInfo)
+
+        val mwQueryResult = mock(MwQueryResult::class.java)
+        whenever(mwQueryResult.pages()).thenReturn(listOf(mwQueryPage))
+
+        val mockResponse = mock(MwQueryResponse::class.java)
+        whenever(mockResponse.query()).thenReturn(mwQueryResult)
+        whenever(mockResponse.continuation()).thenReturn(mockContinuation)
+
+        whenever(
+            mediaInterface!!.getMediaListForUser(
+                ArgumentMatchers.anyString(), ArgumentMatchers.anyInt(),
+                continuationCaptor!!.capture()
+            )
+        )
+            .thenReturn(Observable.just(mockResponse))
+        val media1 = mediaClient!!.getMediaListForUser("Test").blockingGet().get(0)
+        val media2 = mediaClient!!.getMediaListForUser("Test").blockingGet().get(0)
+
+        verify(mediaInterface, times(2))?.getMediaListForUser(
+            ArgumentMatchers.anyString(),
+            ArgumentMatchers.anyInt(), ArgumentMatchers.anyMap<String, String>()
+        )
+    }
+
     @Test
     fun getPageHtmlTest() {
         val mwParseResult = mock(MwParseResult::class.java)
@@ -207,7 +245,7 @@ class MediaClientTest {
         mockResponse.setParse(mwParseResult)
 
         `when`(mediaInterface!!.getPageHtml(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         assertEquals("Test", mediaClient!!.getPageHtml("abcde").blockingGet())
     }
@@ -218,7 +256,7 @@ class MediaClientTest {
         mockResponse.setParse(null)
 
         `when`(mediaInterface!!.getPageHtml(ArgumentMatchers.anyString()))
-                .thenReturn(Observable.just(mockResponse))
+            .thenReturn(Observable.just(mockResponse))
 
         assertEquals("", mediaClient!!.getPageHtml("abcde").blockingGet())
     }

app/src/test/kotlin/fr/free/nrw/commons/utils/NetworkUtilsTest.java

@@ -6,6 +6,7 @@ import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.telephony.TelephonyManager;
 
+import org.jetbrains.annotations.NotNull;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -28,34 +29,30 @@ public class NetworkUtilsTest {
 
     @Test
     public void testInternetConnectionEstablished() {
-        Context mockContext = mock(Context.class);
-        Application mockApplication = mock(Application.class);
-        ConnectivityManager mockConnectivityManager = mock(ConnectivityManager.class);
-        NetworkInfo mockNetworkInfo = mock(NetworkInfo.class);
-        when(mockNetworkInfo.isConnectedOrConnecting())
-                .thenReturn(true);
-        when(mockConnectivityManager.getActiveNetworkInfo())
-                .thenReturn(mockNetworkInfo);
-        when(mockApplication.getSystemService(Context.CONNECTIVITY_SERVICE))
-                .thenReturn(mockConnectivityManager);
-        when(mockContext.getApplicationContext()).thenReturn(mockApplication);
+        Context mockContext = getContext(true);
         boolean internetConnectionEstablished = NetworkUtils.isInternetConnectionEstablished(mockContext);
         assertTrue(internetConnectionEstablished);
     }
 
-    @Test
-    public void testInternetConnectionNotEstablished() {
+    @NotNull
+    public static Context getContext(boolean connectionEstablished) {
         Context mockContext = mock(Context.class);
         Application mockApplication = mock(Application.class);
         ConnectivityManager mockConnectivityManager = mock(ConnectivityManager.class);
         NetworkInfo mockNetworkInfo = mock(NetworkInfo.class);
         when(mockNetworkInfo.isConnectedOrConnecting())
-                .thenReturn(false);
+            .thenReturn(connectionEstablished);
         when(mockConnectivityManager.getActiveNetworkInfo())
-                .thenReturn(mockNetworkInfo);
+            .thenReturn(mockNetworkInfo);
         when(mockApplication.getSystemService(Context.CONNECTIVITY_SERVICE))
-                .thenReturn(mockConnectivityManager);
+            .thenReturn(mockConnectivityManager);
         when(mockContext.getApplicationContext()).thenReturn(mockApplication);
+        return mockContext;
+    }
+
+    @Test
+    public void testInternetConnectionNotEstablished() {
+        Context mockContext = getContext(false);
         boolean internetConnectionEstablished = NetworkUtils.isInternetConnectionEstablished(mockContext);
         assertFalse(internetConnectionEstablished);
     }

app/src/test/kotlin/fr/free/nrw/commons/utils/PagedListMock.kt

@@ -0,0 +1,74 @@
+package fr.free.nrw.commons.utils
+
+
+import android.database.Cursor
+import androidx.lifecycle.LiveData
+import androidx.paging.DataSource
+import androidx.paging.LivePagedListBuilder
+import androidx.paging.PagedList
+import androidx.room.InvalidationTracker
+import androidx.room.RoomDatabase
+import androidx.room.RoomSQLiteQuery
+import androidx.room.paging.LimitOffsetDataSource
+import com.nhaarman.mockitokotlin2.whenever
+import org.mockito.Mockito.mock
+
+fun <T> List<T>.asPagedList(config: PagedList.Config? = null): LiveData<PagedList<T>> {
+    val defaultConfig = PagedList.Config.Builder()
+        .setEnablePlaceholders(false)
+        .setPageSize(size)
+        .setMaxSize(size + 2)
+        .setPrefetchDistance(1)
+        .build()
+    return LivePagedListBuilder<Int, T>(
+        createMockDataSourceFactory(this),
+        config ?: defaultConfig
+    ).build()
+}
+
+/**
+ * Provides a mocked instance of the data source factory
+ */
+fun <T> createMockDataSourceFactory(itemList: List<T>): DataSource.Factory<Int, T> =
+    object : DataSource.Factory<Int, T>() {
+        override fun create(): DataSource<Int, T> = MockLimitDataSource(itemList)
+    }
+
+/**
+ * Provides a mocked Room SQL query
+ */
+private fun mockQuery(): RoomSQLiteQuery? {
+    val query = mock(RoomSQLiteQuery::class.java);
+    whenever(query.sql).thenReturn("");
+    return query;
+}
+
+/**
+ * Provides a mocked Room DB
+ */
+private fun mockDb(): RoomDatabase? {
+    val roomDatabase = mock(RoomDatabase::class.java);
+    val invalidationTracker = mock(InvalidationTracker::class.java)
+    whenever(roomDatabase.invalidationTracker).thenReturn(invalidationTracker);
+    return roomDatabase;
+}
+
+/**
+ * Class that defines the mocked data source
+ */
+class MockLimitDataSource<T>(private val itemList: List<T>) :
+    LimitOffsetDataSource<T>(mockDb(), mockQuery(), false, null) {
+    override fun convertRows(cursor: Cursor?): MutableList<T> = itemList.toMutableList()
+    override fun countItems(): Int = itemList.count()
+    override fun isInvalid(): Boolean = false
+    override fun loadRange(params: LoadRangeParams, callback: LoadRangeCallback<T>) {
+    }
+
+    override fun loadRange(startPosition: Int, loadCount: Int): MutableList<T> {
+        return itemList.subList(startPosition, startPosition + loadCount).toMutableList()
+    }
+
+    override fun loadInitial(params: LoadInitialParams, callback: LoadInitialCallback<T>) {
+        callback.onResult(itemList, 0)
+    }
+}