Improved the DownloadTest to download the smallest ZIM file, as it was previously downloading a 156MB file, which took too much time.

app/src/androidTest/java/org/kiwix/kiwixmobile/download/DownloadRobot.kt

@@ -18,7 +18,11 @@
 
 package org.kiwix.kiwixmobile.download
 
+import android.view.View
+import androidx.recyclerview.widget.RecyclerView
 import androidx.test.espresso.Espresso.onView
+import androidx.test.espresso.UiController
+import androidx.test.espresso.ViewAction
 import androidx.test.espresso.action.ViewActions.click
 import androidx.test.espresso.assertion.ViewAssertions.doesNotExist
 import androidx.test.espresso.assertion.ViewAssertions.matches
@@ -30,6 +34,7 @@ import applyWithViewHierarchyPrinting
 import com.adevinta.android.barista.interaction.BaristaSleepInteractions
 import com.adevinta.android.barista.interaction.BaristaSwipeRefreshInteractions.refresh
 import junit.framework.AssertionFailedError
+import org.hamcrest.Matcher
 import org.junit.Assert
 import org.kiwix.kiwixmobile.BaseRobot
 import org.kiwix.kiwixmobile.Findable.StringId.TextId
@@ -40,6 +45,7 @@ import org.kiwix.kiwixmobile.core.utils.files.Log
 import org.kiwix.kiwixmobile.testutils.TestUtils
 import org.kiwix.kiwixmobile.testutils.TestUtils.testFlakyView
 import org.kiwix.kiwixmobile.utils.RecyclerViewMatcher
+import org.kiwix.kiwixmobile.zimManager.libraryView.adapter.LibraryListItem
 
 fun downloadRobot(func: DownloadRobot.() -> Unit) =
   DownloadRobot().applyWithViewHierarchyPrinting(func)
@@ -102,12 +108,12 @@ class DownloadRobot : BaseRobot() {
     refresh(R.id.librarySwipeRefresh)
   }
 
-  fun downloadZimFile() {
+  fun downloadZimFile(position: Int = 1) {
     pauseForBetterTestPerformance()
     testFlakyView({
       onView(
         RecyclerViewMatcher(R.id.libraryList).atPosition(
-          1
+          position
         )
       ).perform(click())
     })
@@ -190,4 +196,52 @@ class DownloadRobot : BaseRobot() {
       )
     }
   }
+
+  fun getSmallestZimFileIndex(it: List<LibraryListItem>?): Int {
+    var zimFileSizeWithIndex: Pair<Int, Long> = 0 to Long.MAX_VALUE
+    it?.forEachIndexed { index, libraryItem ->
+      if (libraryItem is LibraryListItem.BookItem) {
+        val bookSize = libraryItem.book.size.toLong()
+        if (bookSize < 20000L) {
+          return@getSmallestZimFileIndex index
+        } else if (bookSize < zimFileSizeWithIndex.second) {
+          zimFileSizeWithIndex = index to bookSize
+        }
+      }
+    }
+    return zimFileSizeWithIndex.first
+  }
+
+  fun scrollToZimFileIndex(index: Int) {
+    testFlakyView({
+      onView(withId(R.id.libraryList))
+        .perform(scrollToTop(index))
+    })
+  }
+
+  private fun scrollToTop(position: Int): ViewAction {
+    return object : ViewAction {
+      override fun getDescription(): String =
+        "scroll RecyclerView item at position $position to the top"
+
+      override fun getConstraints(): Matcher<View> =
+        androidx.test.espresso.matcher.ViewMatchers.isAssignableFrom(RecyclerView::class.java)
+
+      override fun perform(uiController: UiController, view: View) {
+        val recyclerView = view as RecyclerView
+        val viewHolder = recyclerView.findViewHolderForAdapterPosition(position)
+
+        if (viewHolder?.itemView == null) {
+          recyclerView.scrollToPosition(position)
+          uiController.loopMainThreadUntilIdle()
+        }
+
+        val newViewHolder = recyclerView.findViewHolderForAdapterPosition(position)
+        newViewHolder?.let {
+          val top = newViewHolder.itemView.top
+          recyclerView.scrollBy(0, top)
+        }
+      }
+    }
+  }
 }

app/src/androidTest/java/org/kiwix/kiwixmobile/download/DownloadTest.kt

@@ -19,6 +19,7 @@ package org.kiwix.kiwixmobile.download
 
 import androidx.core.content.edit
 import androidx.lifecycle.Lifecycle
+import androidx.navigation.fragment.NavHostFragment
 import androidx.preference.PreferenceManager
 import androidx.test.core.app.ActivityScenario
 import androidx.test.espresso.IdlingPolicies
@@ -39,7 +40,6 @@ import org.junit.After
 import org.junit.Assert
 import org.junit.Before
 import org.junit.BeforeClass
-import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.kiwix.kiwixmobile.BaseActivityTest
@@ -49,21 +49,24 @@ import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
 import org.kiwix.kiwixmobile.main.KiwixMainActivity
 import org.kiwix.kiwixmobile.main.topLevel
 import org.kiwix.kiwixmobile.nav.destination.library.LibraryRobot
+import org.kiwix.kiwixmobile.nav.destination.library.OnlineLibraryFragment
 import org.kiwix.kiwixmobile.nav.destination.library.library
-import org.kiwix.kiwixmobile.testutils.RetryRule
 import org.kiwix.kiwixmobile.testutils.TestUtils
 import org.kiwix.kiwixmobile.testutils.TestUtils.closeSystemDialogs
 import org.kiwix.kiwixmobile.testutils.TestUtils.isSystemUINotRespondingDialogVisible
 import org.kiwix.kiwixmobile.utils.KiwixIdlingResource.Companion.getInstance
+import org.kiwix.kiwixmobile.zimManager.libraryView.adapter.LibraryListItem
 import java.util.concurrent.TimeUnit
 
 @LargeTest
 @RunWith(AndroidJUnit4::class)
 class DownloadTest : BaseActivityTest() {
 
-  @Rule
+  // @Rule
-  @JvmField
+  // @JvmField
-  var retryRule = RetryRule()
+  // var retryRule = RetryRule()
+
+  private lateinit var kiwixMainActivity: KiwixMainActivity
 
   init {
     AccessibilityChecks.enable().apply {
@@ -115,14 +118,24 @@ class DownloadTest : BaseActivityTest() {
   fun downloadTest() {
     BaristaSleepInteractions.sleep(TestUtils.TEST_PAUSE_MS.toLong())
     activityScenario.onActivity {
+      kiwixMainActivity = it
       it.navigate(R.id.libraryFragment)
     }
     try {
+      // delete all the ZIM files showing in the LocalLibrary
+      // screen to properly test the scenario.
+      library {
+        refreshList()
+        waitUntilZimFilesRefreshing()
+        deleteZimIfExists()
+      }
       downloadRobot {
         clickDownloadOnBottomNav()
         waitForDataToLoad()
+        val smallestZimFileIndex = getSmallestZimFileIndex(getOnlineLibraryList())
+        scrollToZimFileIndex(smallestZimFileIndex)
         stopDownloadIfAlreadyStarted()
-        downloadZimFile()
+        downloadZimFile(smallestZimFileIndex)
         assertDownloadStart()
         pauseDownload()
         assertDownloadPaused()
@@ -142,6 +155,15 @@ class DownloadTest : BaseActivityTest() {
     LeakAssertions.assertNoLeaks()
   }
 
+  private fun getOnlineLibraryList(): List<LibraryListItem> {
+    val navHostFragment: NavHostFragment =
+      kiwixMainActivity.supportFragmentManager
+        .findFragmentById(R.id.nav_host_fragment) as NavHostFragment
+    val onlineLibraryFragment =
+      navHostFragment.childFragmentManager.fragments[0] as OnlineLibraryFragment
+    return onlineLibraryFragment.getOnlineLibraryList()
+  }
+
   @Test
   fun testPauseAndResumeInOtherLanguage() {
     BaristaSleepInteractions.sleep(TestUtils.TEST_PAUSE_MS.toLong())
@@ -149,6 +171,13 @@ class DownloadTest : BaseActivityTest() {
       it.navigate(R.id.libraryFragment)
     }
     try {
+      // delete all the ZIM files showing in the LocalLibrary
+      // screen to properly test the scenario.
+      library {
+        refreshList()
+        waitUntilZimFilesRefreshing()
+        deleteZimIfExists()
+      }
       downloadRobot {
         // change the application language
         topLevel {

app/src/main/java/org/kiwix/kiwixmobile/nav/destination/library/OnlineLibraryFragment.kt

@@ -34,6 +34,7 @@ import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
 import android.widget.Toast
+import androidx.annotation.VisibleForTesting
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.SearchView
 import androidx.appcompat.widget.Toolbar
@@ -111,6 +112,9 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
     requireActivity().viewModel<ZimManageViewModel>(viewModelFactory)
   }
 
+  @VisibleForTesting
+  fun getOnlineLibraryList() = libraryAdapter.items
+
   private val libraryAdapter: LibraryAdapter by lazy {
     LibraryAdapter(
       LibraryDelegate.BookDelegate(bookUtils, ::onBookItemClick, availableSpaceCalculator),