Merge pull request #4322 from kiwix/Fixes#4308

Refactored the `RxJava` to coroutines in `PageViewModel`.

app/src/androidTest/java/org/kiwix/kiwixmobile/KiwixRoomDatabaseTest.kt

@@ -112,7 +112,7 @@ class KiwixRoomDatabaseTest {
 
       // test inserting into history database
       historyRoomDao.saveHistory(historyItem)
-      var historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      var historyList = historyRoomDao.historyRoomEntity().first()
       with(historyList.first()) {
         assertThat(historyTitle, equalTo(historyItem.title))
         assertThat(zimId, equalTo(historyItem.zimId))
@@ -126,7 +126,7 @@ class KiwixRoomDatabaseTest {
 
       // test deleting the history
       historyRoomDao.deleteHistory(listOf(historyItem))
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertEquals(historyList.size, 0)
 
       // test deleting all history
@@ -134,10 +134,10 @@ class KiwixRoomDatabaseTest {
       historyRoomDao.saveHistory(
         getHistoryItem(databaseId = 2)
       )
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertEquals(historyList.size, 2)
       historyRoomDao.deleteAllHistory()
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertEquals(historyList.size, 0)
     }
 
@@ -146,7 +146,7 @@ class KiwixRoomDatabaseTest {
     runBlocking {
       notesRoomDao = db.notesRoomDao()
       // delete all the notes from database to properly run the test cases.
-      notesRoomDao.deleteNotes(notesRoomDao.notes().blockingFirst() as List<NoteListItem>)
+      notesRoomDao.deleteNotes(notesRoomDao.notes().first() as List<NoteListItem>)
       val noteItem =
         getNoteListItem(
           zimUrl = "http://kiwix.app/MainPage",
@@ -155,7 +155,7 @@ class KiwixRoomDatabaseTest {
 
       // Save and retrieve a notes item
       notesRoomDao.saveNote(noteItem)
-      var notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      var notesList = notesRoomDao.notes().first() as List<NoteListItem>
       with(notesList.first()) {
         assertThat(zimId, equalTo(noteItem.zimId))
         assertThat(zimUrl, equalTo(noteItem.zimUrl))
@@ -168,7 +168,7 @@ class KiwixRoomDatabaseTest {
 
       // test deleting the history
       notesRoomDao.deleteNotes(listOf(noteItem))
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 0)
 
       // test deleting all notes
@@ -179,10 +179,10 @@ class KiwixRoomDatabaseTest {
           zimUrl = "http://kiwix.app/Installing"
         )
       )
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 2)
-      notesRoomDao.deletePages(notesRoomDao.notes().blockingFirst())
+      notesRoomDao.deletePages(notesRoomDao.notes().first())
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 0)
     }
 

app/src/androidTest/java/org/kiwix/kiwixmobile/ObjectBoxToRoomMigratorTest.kt

@@ -215,7 +215,7 @@ class ObjectBoxToRoomMigratorTest {
     kiwixRoomDatabase.recentSearchRoomDao().deleteSearchHistory()
     kiwixRoomDatabase.historyRoomDao().deleteAllHistory()
     kiwixRoomDatabase.notesRoomDao()
-      .deletePages(kiwixRoomDatabase.notesRoomDao().notes().blockingFirst())
+      .deletePages(kiwixRoomDatabase.notesRoomDao().notes().first())
     box.removeAll()
   }
 
@@ -238,7 +238,7 @@ class ObjectBoxToRoomMigratorTest {
       // migrate data into room database
       objectBoxToRoomMigrator.migrateHistory(box)
       // check if data successfully migrated to room
-      val actual = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      val actual = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       with(actual.first()) {
         assertThat(historyTitle, equalTo(historyItem.title))
         assertThat(zimId, equalTo(historyItem.zimId))
@@ -254,7 +254,7 @@ class ObjectBoxToRoomMigratorTest {
 
       // Migrate data from empty ObjectBox database
       objectBoxToRoomMigrator.migrateHistory(box)
-      var actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      var actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       assertTrue(actualData.isEmpty())
 
       // Test if data successfully migrated to Room and existing data is preserved
@@ -262,7 +262,7 @@ class ObjectBoxToRoomMigratorTest {
       box.put(HistoryEntity(historyItem2))
       // Migrate data into Room database
       objectBoxToRoomMigrator.migrateHistory(box)
-      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       assertEquals(2, actualData.size)
       val existingItem =
         actualData.find {
@@ -281,7 +281,7 @@ class ObjectBoxToRoomMigratorTest {
       kiwixRoomDatabase.historyRoomDao().saveHistory(historyItem)
       box.put(HistoryEntity(historyItem))
       objectBoxToRoomMigrator.migrateHistory(box)
-      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       assertEquals(1, actualData.size)
 
       clearRoomAndBoxStoreDatabases(box)
@@ -296,7 +296,7 @@ class ObjectBoxToRoomMigratorTest {
       kiwixRoomDatabase.historyRoomDao().saveHistory(historyItem4)
       box.put(HistoryEntity(historyItem))
       objectBoxToRoomMigrator.migrateHistory(box)
-      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       assertEquals(2, actualData.size)
 
       clearRoomAndBoxStoreDatabases(box)
@@ -310,7 +310,7 @@ class ObjectBoxToRoomMigratorTest {
       } catch (_: Exception) {
       }
       // Ensure Room database remains empty or unaffected by the invalid data
-      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       assertTrue(actualData.isEmpty())
 
       // Test large data migration for recent searches
@@ -332,7 +332,7 @@ class ObjectBoxToRoomMigratorTest {
       val endTime = System.currentTimeMillis()
       val migrationTime = endTime - startTime
       // Check if data successfully migrated to Room
-      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().blockingFirst()
+      actualData = kiwixRoomDatabase.historyRoomDao().historyRoomEntity().first()
       assertEquals(numEntities, actualData.size)
       // Assert that the migration completes within a reasonable time frame
       assertTrue(
@@ -367,7 +367,7 @@ class ObjectBoxToRoomMigratorTest {
       // migrate data into room database
       objectBoxToRoomMigrator.migrateNotes(box)
       // check if data successfully migrated to room
-      var notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      var notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       with(notesList.first()) {
         assertThat(zimId, equalTo(noteItem.zimId))
         assertThat(zimUrl, equalTo(noteItem.zimUrl))
@@ -382,7 +382,7 @@ class ObjectBoxToRoomMigratorTest {
 
       // Migrate data from empty ObjectBox database
       objectBoxToRoomMigrator.migrateNotes(box)
-      notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       assertTrue(notesList.isEmpty())
 
       // Test if data successfully migrated to Room and existing data is preserved
@@ -390,7 +390,7 @@ class ObjectBoxToRoomMigratorTest {
       box.put(NotesEntity(noteItem))
       // Migrate data into Room database
       objectBoxToRoomMigrator.migrateNotes(box)
-      notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       assertEquals(noteItem.title, notesList.first().title)
       assertEquals(2, notesList.size)
       val existingItem =
@@ -411,7 +411,7 @@ class ObjectBoxToRoomMigratorTest {
       box.put(NotesEntity(noteItem1))
       // Migrate data into Room database
       objectBoxToRoomMigrator.migrateNotes(box)
-      notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       assertEquals(1, notesList.size)
 
       clearRoomAndBoxStoreDatabases(box)
@@ -426,7 +426,7 @@ class ObjectBoxToRoomMigratorTest {
       kiwixRoomDatabase.notesRoomDao().saveNote(noteItem1)
       box.put(NotesEntity(noteItem2))
       objectBoxToRoomMigrator.migrateNotes(box)
-      notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       assertEquals(2, notesList.size)
 
       clearRoomAndBoxStoreDatabases(box)
@@ -440,7 +440,7 @@ class ObjectBoxToRoomMigratorTest {
       } catch (_: Exception) {
       }
       // Ensure Room database remains empty or unaffected by the invalid data
-      notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       assertTrue(notesList.isEmpty())
 
       // Test large data migration for recent searches
@@ -462,7 +462,7 @@ class ObjectBoxToRoomMigratorTest {
       val endTime = System.currentTimeMillis()
       val migrationTime = endTime - startTime
       // Check if data successfully migrated to Room
-      notesList = kiwixRoomDatabase.notesRoomDao().notes().blockingFirst() as List<NoteListItem>
+      notesList = kiwixRoomDatabase.notesRoomDao().notes().first() as List<NoteListItem>
       assertEquals(numEntities, notesList.size)
       // Assert that the migration completes within a reasonable time frame
       assertTrue(

app/src/androidTest/java/org/kiwix/kiwixmobile/roomDao/HistoryRoomDaoTest.kt

@@ -22,6 +22,7 @@ import android.content.Context
 import androidx.room.Room
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
 import org.hamcrest.MatcherAssert.assertThat
 import org.hamcrest.core.IsEqual.equalTo
@@ -66,7 +67,7 @@ class HistoryRoomDaoTest {
 
       // Save and retrieve a history item
       historyRoomDao.saveHistory(historyItem)
-      var historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      var historyList = historyRoomDao.historyRoomEntity().first()
       with(historyList.first()) {
         assertThat(historyTitle, equalTo(historyItem.title))
         assertThat(zimId, equalTo(historyItem.zimId))
@@ -80,26 +81,26 @@ class HistoryRoomDaoTest {
 
       // Test to update the same day history for url
       historyRoomDao.saveHistory(historyItem)
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertEquals(historyList.size, 1)
 
       // Delete the saved history item
       historyRoomDao.deleteHistory(listOf(historyItem))
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertEquals(historyList.size, 0)
 
       // Save and delete all history items
       historyRoomDao.saveHistory(historyItem)
       historyRoomDao.saveHistory(getHistoryItem(databaseId = 2, dateString = "31 May 2024"))
       historyRoomDao.deleteAllHistory()
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertThat(historyList.size, equalTo(0))
 
       // Save history item with empty fields
       val emptyHistoryUrl = ""
       val emptyTitle = ""
       historyRoomDao.saveHistory(getHistoryItem(emptyTitle, emptyHistoryUrl, databaseId = 1))
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertThat(historyList.size, equalTo(1))
       historyRoomDao.deleteAllHistory()
 
@@ -113,14 +114,14 @@ class HistoryRoomDaoTest {
           dateString = "31 May 2024"
         )
       historyRoomDao.saveHistory(historyItem1)
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertThat(historyList.size, equalTo(2))
       historyRoomDao.deleteAllHistory()
 
       // Save two entity with same and database id with same date to see if it's updated or not.
       historyRoomDao.saveHistory(historyItem)
       historyRoomDao.saveHistory(historyItem)
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertThat(historyList.size, equalTo(1))
       historyRoomDao.deleteAllHistory()
 
@@ -132,7 +133,7 @@ class HistoryRoomDaoTest {
           "Undefined value was saved into database",
           false
         )
-      } catch (e: Exception) {
+      } catch (_: Exception) {
         assertThat("Undefined value was not saved, as expected.", true)
       }
 
@@ -140,13 +141,13 @@ class HistoryRoomDaoTest {
       val unicodeTitle = "title \u03A3" // Unicode character for Greek capital letter Sigma
       val historyItem2 = getHistoryItem(title = unicodeTitle, databaseId = 2)
       historyRoomDao.saveHistory(historyItem2)
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertThat(historyList.first().historyTitle, equalTo("title Σ"))
 
       // Test deletePages function
       historyRoomDao.saveHistory(historyItem)
       historyRoomDao.deletePages(listOf(historyItem, historyItem2))
-      historyList = historyRoomDao.historyRoomEntity().blockingFirst()
+      historyList = historyRoomDao.historyRoomEntity().first()
       assertThat(historyList.size, equalTo(0))
     }
 }

app/src/androidTest/java/org/kiwix/kiwixmobile/roomDao/NoteRoomDaoTest.kt

@@ -22,6 +22,7 @@ import android.content.Context
 import androidx.room.Room
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
 import org.hamcrest.MatcherAssert.assertThat
 import org.hamcrest.core.IsEqual.equalTo
@@ -65,7 +66,7 @@ class NoteRoomDaoTest {
 
       // Save and retrieve a notes item
       notesRoomDao.saveNote(noteItem)
-      var notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      var notesList = notesRoomDao.notes().first() as List<NoteListItem>
       with(notesList.first()) {
         assertThat(zimId, equalTo(noteItem.zimId))
         assertThat(zimUrl, equalTo(noteItem.zimUrl))
@@ -78,25 +79,25 @@ class NoteRoomDaoTest {
 
       // Test update the existing note
       notesRoomDao.saveNote(noteItem)
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 1)
 
       // Delete the saved note item with all delete methods available in NoteRoomDao.
       // delete via noteTitle
       notesRoomDao.deleteNote(noteItem.title)
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 0)
 
       // delete with deletePages method
       notesRoomDao.saveNote(noteItem)
       notesRoomDao.deletePages(listOf(noteItem))
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 0)
 
       // delete with list of NoteListItem
       notesRoomDao.saveNote(noteItem)
       notesRoomDao.deleteNotes(listOf(noteItem))
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 0)
 
       // Save note with empty title
@@ -107,7 +108,7 @@ class NoteRoomDaoTest {
           noteFilePath = "/storage/emulated/0/Download/Notes/Alpine linux/Installing.txt"
         )
       )
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(notesList.size, 1)
       clearNotes()
 
@@ -127,7 +128,7 @@ class NoteRoomDaoTest {
         )
       kiwixRoomDatabase.notesRoomDao().saveNote(noteItem2)
       kiwixRoomDatabase.notesRoomDao().saveNote(noteItem3)
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertEquals(2, notesList.size)
       clearNotes()
 
@@ -139,7 +140,7 @@ class NoteRoomDaoTest {
           "Undefined value was saved into database",
           false
         )
-      } catch (e: Exception) {
+      } catch (_: Exception) {
         assertThat("Undefined value was not saved, as expected.", true)
       }
 
@@ -148,11 +149,11 @@ class NoteRoomDaoTest {
       val noteListItem2 =
         getNoteListItem(title = unicodeTitle, zimUrl = "http://kiwix.app/Installing")
       notesRoomDao.saveNote(noteListItem2)
-      notesList = notesRoomDao.notes().blockingFirst() as List<NoteListItem>
+      notesList = notesRoomDao.notes().first() as List<NoteListItem>
       assertThat(notesList.first().title, equalTo("title Σ"))
     }
 
   private suspend fun clearNotes() {
-    notesRoomDao.deleteNotes(notesRoomDao.notes().blockingFirst() as List<NoteListItem>)
+    notesRoomDao.deleteNotes(notesRoomDao.notes().first() as List<NoteListItem>)
   }
 }

app/src/main/java/org/kiwix/kiwixmobile/language/LanguageFragment.kt

@@ -31,7 +31,6 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.ComposeView
 import androidx.lifecycle.ViewModelProvider
-import io.reactivex.disposables.CompositeDisposable
 import org.kiwix.kiwixmobile.cachedComponent
 import org.kiwix.kiwixmobile.core.R
 import org.kiwix.kiwixmobile.core.base.BaseActivity
@@ -55,7 +54,6 @@ class LanguageFragment : BaseFragment() {
 
   @Inject lateinit var viewModelFactory: ViewModelProvider.Factory
   private var composeView: ComposeView? = null
-  private val compositeDisposable = CompositeDisposable()
 
   override fun inject(baseActivity: BaseActivity) {
     baseActivity.cachedComponent.inject(this)
@@ -153,7 +151,6 @@ class LanguageFragment : BaseFragment() {
 
   override fun onDestroyView() {
     super.onDestroyView()
-    compositeDisposable.clear()
     composeView?.disposeComposition()
     composeView = null
   }

app/src/main/java/org/kiwix/kiwixmobile/language/viewmodel/LanguageViewModel.kt

@@ -25,8 +25,9 @@ import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.launch
+import kotlinx.coroutines.flow.onEach
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.NewLanguagesDao
 import org.kiwix.kiwixmobile.language.composables.LanguageListItem.LanguageItem
@@ -55,21 +56,17 @@ class LanguageViewModel @Inject constructor(
   }
 
   private fun observeActions() =
-    viewModelScope.launch {
     actions
       .map { action -> reduce(action, state.value) }
       .distinctUntilChanged()
-        .collect { newState -> state.value = newState }
+      .onEach { newState -> state.value = newState }
-    }
+      .launchIn(viewModelScope)
 
   private fun observeLanguages() =
-    viewModelScope.launch {
     languageDao.languages()
       .filter { it.isNotEmpty() }
-        .collect { languages ->
+      .onEach { languages -> actions.tryEmit(UpdateLanguages(languages)) }
-          actions.tryEmit(UpdateLanguages(languages))
+      .launchIn(viewModelScope)
-        }
-    }
 
   override fun onCleared() {
     coroutineJobs.forEach {

core/src/main/java/org/kiwix/kiwixmobile/core/base/BasePresenter.kt

@@ -17,7 +17,6 @@
  */
 package org.kiwix.kiwixmobile.core.base
 
-import io.reactivex.disposables.CompositeDisposable
 import org.kiwix.kiwixmobile.core.base.BaseContract.Presenter
 import org.kiwix.kiwixmobile.core.base.BaseContract.View
 
@@ -26,9 +25,6 @@ import org.kiwix.kiwixmobile.core.base.BaseContract.View
  */
 @Suppress("UnnecessaryAbstractClass")
 abstract class BasePresenter<T : View<*>?> : Presenter<T> {
-  @JvmField
-  val compositeDisposable = CompositeDisposable()
-
   @JvmField
   var view: T? = null
 
@@ -38,6 +34,5 @@ abstract class BasePresenter<T : View<*>?> : Presenter<T> {
 
   override fun detachView() {
     view = null
-    compositeDisposable.clear()
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/dao/HistoryDao.kt

@@ -20,7 +20,8 @@ package org.kiwix.kiwixmobile.core.dao
 import io.objectbox.Box
 import io.objectbox.kotlin.query
 import io.objectbox.query.QueryBuilder
-import io.reactivex.Flowable
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 import org.kiwix.kiwixmobile.core.dao.entities.HistoryEntity
 import org.kiwix.kiwixmobile.core.dao.entities.HistoryEntity_
 import org.kiwix.kiwixmobile.core.page.adapter.Page
@@ -29,8 +30,8 @@ import org.kiwix.kiwixmobile.core.reader.ZimReaderSource.Companion.fromDatabaseV
 import javax.inject.Inject
 
 class HistoryDao @Inject constructor(val box: Box<HistoryEntity>) : PageDao {
-  fun history(): Flowable<List<Page>> =
+  fun history(): Flow<List<Page>> =
-    box.asFlowable(
+    box.asFlow(
       box.query {
         orderDesc(HistoryEntity_.timeStamp)
       }
@@ -46,7 +47,7 @@ class HistoryDao @Inject constructor(val box: Box<HistoryEntity>) : PageDao {
       }
     }
 
-  override fun pages(): Flowable<List<Page>> = history()
+  override fun pages(): Flow<List<Page>> = history()
   override fun deletePages(pagesToDelete: List<Page>) =
     deleteHistory(pagesToDelete as List<HistoryItem>)
 

core/src/main/java/org/kiwix/kiwixmobile/core/dao/HistoryRoomDao.kt

@@ -24,7 +24,8 @@ import androidx.room.Insert
 import androidx.room.Query
 import androidx.room.TypeConverter
 import androidx.room.Update
-import io.reactivex.Flowable
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 import org.kiwix.kiwixmobile.core.dao.entities.HistoryRoomEntity
 import org.kiwix.kiwixmobile.core.page.adapter.Page
 import org.kiwix.kiwixmobile.core.page.history.adapter.HistoryListItem
@@ -33,9 +34,9 @@ import org.kiwix.kiwixmobile.core.reader.ZimReaderSource
 @Dao
 abstract class HistoryRoomDao : PageDao {
   @Query("SELECT * FROM HistoryRoomEntity ORDER BY HistoryRoomEntity.timeStamp DESC")
-  abstract fun historyRoomEntity(): Flowable<List<HistoryRoomEntity>>
+  abstract fun historyRoomEntity(): Flow<List<HistoryRoomEntity>>
 
-  fun history(): Flowable<List<Page>> =
+  fun history(): Flow<List<Page>> =
     historyRoomEntity().map {
       it.map { historyEntity ->
         historyEntity.zimFilePath?.let { filePath ->

core/src/main/java/org/kiwix/kiwixmobile/core/dao/LibkiwixBookmarks.kt

@@ -21,7 +21,6 @@ package org.kiwix.kiwixmobile.core.dao
 import android.os.Build
 import android.os.Environment
 import android.util.Base64
-import io.reactivex.Flowable
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -30,7 +29,6 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.reactive.asPublisher
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
 import org.kiwix.kiwixmobile.core.CoreApp
@@ -121,10 +119,7 @@ class LibkiwixBookmarks @Inject constructor(
     bookmarkListFlow
       .map { it }
 
-  // Currently kept in RxJava Flowable because `PageViewModel` still expects RxJava streams.
+  override fun pages(): Flow<List<Page>> = bookmarks()
-  // This can be refactored to use Kotlin Flow once `PageViewModel` is migrated to coroutines.
-  override fun pages(): Flowable<List<Page>> =
-    Flowable.fromPublisher(bookmarks().asPublisher())
 
   override fun deletePages(pagesToDelete: List<Page>) =
     deleteBookmarks(pagesToDelete as List<LibkiwixBookmarkItem>)

core/src/main/java/org/kiwix/kiwixmobile/core/dao/NewBookmarksDao.kt

@@ -20,8 +20,11 @@ package org.kiwix.kiwixmobile.core.dao
 import io.objectbox.Box
 import io.objectbox.kotlin.query
 import io.objectbox.query.QueryBuilder
-import io.reactivex.Flowable
+import kotlinx.coroutines.CoroutineDispatcher
-import io.reactivex.schedulers.Schedulers
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
 import org.kiwix.kiwixmobile.core.dao.entities.BookmarkEntity
 import org.kiwix.kiwixmobile.core.dao.entities.BookmarkEntity_
 import org.kiwix.kiwixmobile.core.page.adapter.Page
@@ -31,8 +34,8 @@ import org.kiwix.kiwixmobile.core.reader.ZimReaderSource.Companion.fromDatabaseV
 import javax.inject.Inject
 
 class NewBookmarksDao @Inject constructor(val box: Box<BookmarkEntity>) : PageDao {
-  fun bookmarks(): Flowable<List<Page>> =
+  fun bookmarks(): Flow<List<Page>> =
-    box.asFlowable(
+    box.asFlow(
       box.query {
         order(BookmarkEntity_.bookmarkTitle)
       }
@@ -48,7 +51,7 @@ class NewBookmarksDao @Inject constructor(val box: Box<BookmarkEntity>) : PageDa
       }
     }
 
-  override fun pages(): Flowable<List<Page>> = bookmarks()
+  override fun pages(): Flow<List<Page>> = bookmarks()
   override fun deletePages(pagesToDelete: List<Page>) =
     deleteBookmarks(pagesToDelete as List<BookmarkItem>)
 
@@ -71,8 +74,11 @@ class NewBookmarksDao @Inject constructor(val box: Box<BookmarkEntity>) : PageDa
       .toList()
       .distinct()
 
-  fun bookmarkUrlsForCurrentBook(zimFileReader: ZimFileReader?): Flowable<List<String>> =
+  fun bookmarkUrlsForCurrentBook(
-    box.asFlowable(
+    zimFileReader: ZimFileReader?,
+    dispatcher: CoroutineDispatcher = Dispatchers.IO
+  ): Flow<List<String>> =
+    box.asFlow(
       box.query {
         equal(
           BookmarkEntity_.zimId,
@@ -88,7 +94,7 @@ class NewBookmarksDao @Inject constructor(val box: Box<BookmarkEntity>) : PageDa
         order(BookmarkEntity_.bookmarkTitle)
       }
     ).map { it.map(BookmarkEntity::bookmarkUrl) }
-      .subscribeOn(Schedulers.io())
+      .flowOn(dispatcher)
 
   fun saveBookmark(bookmarkItem: BookmarkItem) {
     box.put(BookmarkEntity(bookmarkItem))

core/src/main/java/org/kiwix/kiwixmobile/core/dao/NewLanguagesDao.kt

@@ -21,9 +21,6 @@ import io.objectbox.Box
 import io.objectbox.kotlin.flow
 import io.objectbox.kotlin.query
 import io.objectbox.query.Query
-import io.objectbox.rx.RxQuery
-import io.reactivex.BackpressureStrategy
-import io.reactivex.BackpressureStrategy.LATEST
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.distinctUntilChanged
@@ -53,9 +50,3 @@ fun <T> Box<T>.asFlow(query: Query<T> = query {}): Flow<List<T>> {
     .map { it.toList() }
     .distinctUntilChanged()
 }
-
-internal fun <T> Box<T>.asFlowable(
-  query: Query<T> = query {},
-  backpressureStrategy: BackpressureStrategy = LATEST
-) =
-  RxQuery.observable(query).toFlowable(backpressureStrategy)

core/src/main/java/org/kiwix/kiwixmobile/core/dao/NewNoteDao.kt

@@ -21,7 +21,8 @@ package org.kiwix.kiwixmobile.core.dao
 import io.objectbox.Box
 import io.objectbox.kotlin.query
 import io.objectbox.query.QueryBuilder
-import io.reactivex.Flowable
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 import org.kiwix.kiwixmobile.core.dao.entities.NotesEntity
 import org.kiwix.kiwixmobile.core.dao.entities.NotesEntity_
 import org.kiwix.kiwixmobile.core.page.adapter.Page
@@ -30,8 +31,8 @@ import org.kiwix.kiwixmobile.core.reader.ZimReaderSource.Companion.fromDatabaseV
 import javax.inject.Inject
 
 class NewNoteDao @Inject constructor(val box: Box<NotesEntity>) : PageDao {
-  fun notes(): Flowable<List<Page>> =
+  fun notes(): Flow<List<Page>> =
-    box.asFlowable(
+    box.asFlow(
       box.query {
         order(NotesEntity_.noteTitle)
       }
@@ -47,7 +48,7 @@ class NewNoteDao @Inject constructor(val box: Box<NotesEntity>) : PageDao {
       }
     }
 
-  override fun pages(): Flowable<List<Page>> = notes()
+  override fun pages(): Flow<List<Page>> = notes()
 
   override fun deletePages(pagesToDelete: List<Page>) =
     deleteNotes(pagesToDelete as List<NoteListItem>)

core/src/main/java/org/kiwix/kiwixmobile/core/dao/NotesRoomDao.kt

@@ -22,10 +22,11 @@ import androidx.room.Dao
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
 import androidx.room.Query
-import io.reactivex.Flowable
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import org.kiwix.kiwixmobile.core.dao.entities.NotesRoomEntity
 import org.kiwix.kiwixmobile.core.extensions.deleteFile
@@ -38,9 +39,9 @@ import java.io.File
 @Dao
 abstract class NotesRoomDao : PageDao {
   @Query("SELECT * FROM NotesRoomEntity ORDER BY NotesRoomEntity.noteTitle")
-  abstract fun notesAsEntity(): Flowable<List<NotesRoomEntity>>
+  abstract fun notesAsEntity(): Flow<List<NotesRoomEntity>>
 
-  fun notes(): Flowable<List<Page>> =
+  fun notes(): Flow<List<Page>> =
     notesAsEntity().map {
       it.map { notesEntity ->
         notesEntity.zimFilePath?.let { filePath ->
@@ -53,7 +54,7 @@ abstract class NotesRoomDao : PageDao {
       }
     }
 
-  override fun pages(): Flowable<List<Page>> = notes()
+  override fun pages(): Flow<List<Page>> = notes()
   override fun deletePages(pagesToDelete: List<Page>) =
     deleteNotes(pagesToDelete as List<NoteListItem>)
 

core/src/main/java/org/kiwix/kiwixmobile/core/dao/PageDao.kt

@@ -18,10 +18,10 @@
 
 package org.kiwix.kiwixmobile.core.dao
 
-import io.reactivex.Flowable
+import kotlinx.coroutines.flow.Flow
 import org.kiwix.kiwixmobile.core.page.adapter.Page
 
 interface PageDao {
-  fun pages(): Flowable<List<Page>>
+  fun pages(): Flow<List<Page>>
   fun deletePages(pagesToDelete: List<Page>)
 }

core/src/main/java/org/kiwix/kiwixmobile/core/page/PageFragment.kt

@@ -32,13 +32,16 @@ import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.referentialEqualityPolicy
 import androidx.compose.ui.platform.ComposeView
-import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProvider
-import io.reactivex.disposables.CompositeDisposable
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
 import org.kiwix.kiwixmobile.core.R
 import org.kiwix.kiwixmobile.core.base.BaseFragment
 import org.kiwix.kiwixmobile.core.base.FragmentActivityExtensions
 import org.kiwix.kiwixmobile.core.downloader.downloadManager.ZERO
+import org.kiwix.kiwixmobile.core.extensions.update
 import org.kiwix.kiwixmobile.core.main.CoreMainActivity
 import org.kiwix.kiwixmobile.core.page.adapter.OnItemClickListener
 import org.kiwix.kiwixmobile.core.page.adapter.Page
@@ -66,7 +69,7 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
 
   @Inject lateinit var alertDialogShower: AlertDialogShower
   private var actionMode: ActionMode? = null
-  val compositeDisposable = CompositeDisposable()
+  private val coroutineJobs = mutableListOf<Job>()
   abstract val screenTitle: Int
   abstract val noItemsString: String
   abstract val switchString: String
@@ -116,36 +119,51 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
 
       override fun onActionItemClicked(mode: ActionMode, item: MenuItem): Boolean {
         if (item.itemId == R.id.menu_context_delete) {
-          pageViewModel.actions.offer(Action.UserClickedDeleteSelectedPages)
+          pageViewModel.actions.tryEmit(Action.UserClickedDeleteSelectedPages)
           return true
         }
-        pageViewModel.actions.offer(Action.ExitActionModeMenu)
+        pageViewModel.actions.tryEmit(Action.ExitActionModeMenu)
         return false
       }
 
       override fun onDestroyActionMode(mode: ActionMode) {
-        pageViewModel.actions.offer(Action.ExitActionModeMenu)
+        pageViewModel.actions.tryEmit(Action.ExitActionModeMenu)
         actionMode = null
       }
     }
 
   override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
     super.onViewCreated(view, savedInstanceState)
-    pageScreenState.value = pageScreenState.value.copy(
+    pageScreenState.update {
-      searchQueryHint = searchQueryHint,
+      copy(
+        searchQueryHint = this@PageFragment.searchQueryHint,
         searchText = "",
         searchValueChangedListener = { onTextChanged(it) },
         clearSearchButtonClickListener = { onTextChanged("") },
-      screenTitle = screenTitle,
+        screenTitle = this@PageFragment.screenTitle,
-      noItemsString = noItemsString,
+        noItemsString = this@PageFragment.noItemsString,
-      switchString = switchString,
+        switchString = this@PageFragment.switchString,
-      switchIsChecked = switchIsChecked,
+        switchIsChecked = this@PageFragment.switchIsChecked,
-      onSwitchCheckedChanged = { onSwitchCheckedChanged(it).invoke() },
+        onSwitchCheckedChanged = { onSwitchChanged(it).invoke() },
-      deleteIconTitle = deleteIconTitle
+        deleteIconTitle = this@PageFragment.deleteIconTitle
       )
+    }
     val activity = requireActivity() as CoreMainActivity
-    compositeDisposable.add(pageViewModel.effects.subscribe { it.invokeWith(activity) })
+    cancelCoroutineJobs()
-    pageViewModel.state.observe(viewLifecycleOwner, Observer(::render))
+    coroutineJobs.apply {
+      add(
+        pageViewModel
+          .effects
+          .onEach { it.invokeWith(activity) }
+          .launchIn(lifecycleScope)
+      )
+      add(
+        pageViewModel
+          .state
+          .onEach { render(it) }
+          .launchIn(lifecycleScope)
+      )
+    }
     pageViewModel.alertDialogShower = alertDialogShower
   }
 
@@ -168,9 +186,9 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
             isSearchActive = pageScreenState.value.isSearchActive,
             onSearchClick = {
               // Set the `isSearchActive` when the search button is clicked.
-              pageScreenState.value = pageScreenState.value.copy(isSearchActive = true)
+              pageScreenState.update { copy(isSearchActive = true) }
             },
-            onDeleteClick = { pageViewModel.actions.offer(Action.UserClickedDeleteButton) }
+            onDeleteClick = { pageViewModel.actions.tryEmit(Action.UserClickedDeleteButton) }
           )
         )
         DialogHost(alertDialogShower)
@@ -186,8 +204,8 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
    * @param searchText The current text entered in the search bar.
    */
   private fun onTextChanged(searchText: String) {
-    pageScreenState.value = pageScreenState.value.copy(searchText = searchText)
+    pageScreenState.update { copy(searchText = searchText) }
-    pageViewModel.actions.offer(Action.Filter(searchText))
+    pageViewModel.actions.tryEmit(Action.Filter(searchText))
   }
 
   /**
@@ -197,9 +215,9 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
    *
    * @param isChecked The new checked state of the switch.
    */
-  private fun onSwitchCheckedChanged(isChecked: Boolean): () -> Unit = {
+  private fun onSwitchChanged(isChecked: Boolean): () -> Unit = {
-    pageScreenState.value = pageScreenState.value.copy(switchIsChecked = isChecked)
+    pageScreenState.update { copy(switchIsChecked = isChecked) }
-    pageViewModel.actions.offer(Action.UserClickedShowAllToggle(isChecked))
+    pageViewModel.actions.tryEmit(Action.UserClickedShowAllToggle(isChecked))
   }
 
   /**
@@ -209,7 +227,7 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
    */
   private fun navigationIconClick(): () -> Unit = {
     if (pageScreenState.value.isSearchActive) {
-      pageScreenState.value = pageScreenState.value.copy(isSearchActive = false)
+      pageScreenState.update { copy(isSearchActive = false) }
       onTextChanged("")
     } else {
       requireActivity().onBackPressedDispatcher.onBackPressed()
@@ -255,21 +273,20 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
 
   override fun onDestroyView() {
     super.onDestroyView()
-    compositeDisposable.clear()
+    cancelCoroutineJobs()
+  }
+
+  private fun cancelCoroutineJobs() {
+    coroutineJobs.forEach {
+      it.cancel()
+    }
+    coroutineJobs.clear()
   }
 
   private fun render(state: PageState<*>) {
-    pageScreenState.value = pageScreenState.value.copy(
+    pageScreenState.update {
-      switchIsEnabled = !state.isInSelectionState,
+      copy(switchIsEnabled = !state.isInSelectionState, pageState = state)
-      // First, assign the existing state to force Compose to recognize a change.
+    }
-      // This helps when internal properties of items (like `isSelected`) change,
-      // but the list reference itself remains the same — Compose won't detect it otherwise.
-      pageState = pageState.value
-    )
-    // Then, assign the actual updated state to trigger full recomposition.
-    pageScreenState.value = pageScreenState.value.copy(
-      pageState = state
-    )
     if (state.isInSelectionState) {
       if (actionMode == null) {
         actionMode =
@@ -282,9 +299,9 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
   }
 
   override fun onItemClick(page: Page) {
-    pageViewModel.actions.offer(Action.OnItemClick(page))
+    pageViewModel.actions.tryEmit(Action.OnItemClick(page))
   }
 
   override fun onItemLongClick(page: Page): Boolean =
-    pageViewModel.actions.offer(Action.OnItemLongClick(page))
+    pageViewModel.actions.tryEmit(Action.OnItemLongClick(page))
 }

core/src/main/java/org/kiwix/kiwixmobile/core/page/bookmark/viewmodel/BookmarkViewModel.kt

@@ -57,7 +57,7 @@ class BookmarkViewModel @Inject constructor(
     action: Action.UserClickedShowAllToggle,
     state: BookmarkState
   ): BookmarkState {
-    effects.offer(UpdateAllBookmarksPreference(sharedPreferenceUtil, action.isChecked))
+    effects.tryEmit(UpdateAllBookmarksPreference(sharedPreferenceUtil, action.isChecked))
     return state.copy(showAll = action.isChecked)
   }
 

core/src/main/java/org/kiwix/kiwixmobile/core/page/bookmark/viewmodel/effects/ShowDeleteBookmarksDialog.kt

@@ -19,8 +19,8 @@ package org.kiwix.kiwixmobile.core.page.bookmark.viewmodel.effects
  */
 
 import androidx.appcompat.app.AppCompatActivity
-import io.reactivex.processors.PublishProcessor
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableSharedFlow
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.PageDao
 import org.kiwix.kiwixmobile.core.extensions.ActivityExtensions.cachedComponent
@@ -32,7 +32,7 @@ import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteAllBookmarks
 import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteSelectedBookmarks
 
 data class ShowDeleteBookmarksDialog(
-  private val effects: PublishProcessor<SideEffect<*>>,
+  private val effects: MutableSharedFlow<SideEffect<*>>,
   private val state: PageState<LibkiwixBookmarkItem>,
   private val pageDao: PageDao,
   private val viewModelScope: CoroutineScope,
@@ -42,7 +42,7 @@ data class ShowDeleteBookmarksDialog(
     activity.cachedComponent.inject(this)
     dialogShower.show(
       if (state.isInSelectionState) DeleteSelectedBookmarks else DeleteAllBookmarks,
-      { effects.offer(DeletePageItems(state, pageDao, viewModelScope)) }
+      { effects.tryEmit(DeletePageItems(state, pageDao, viewModelScope)) }
     )
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/page/history/viewmodel/HistoryViewModel.kt

@@ -53,7 +53,7 @@ class HistoryViewModel @Inject constructor(
     action: Action.UserClickedShowAllToggle,
     state: HistoryState
   ): HistoryState {
-    effects.offer(UpdateAllHistoryPreference(sharedPreferenceUtil, action.isChecked))
+    effects.tryEmit(UpdateAllHistoryPreference(sharedPreferenceUtil, action.isChecked))
     return state.copy(showAll = action.isChecked)
   }
 

core/src/main/java/org/kiwix/kiwixmobile/core/page/history/viewmodel/effects/ShowDeleteHistoryDialog.kt

@@ -19,8 +19,8 @@ package org.kiwix.kiwixmobile.core.page.history.viewmodel.effects
  */
 
 import androidx.appcompat.app.AppCompatActivity
-import io.reactivex.processors.PublishProcessor
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableSharedFlow
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.PageDao
 import org.kiwix.kiwixmobile.core.extensions.ActivityExtensions.cachedComponent
@@ -31,7 +31,7 @@ import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteAllHistory
 import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteSelectedHistory
 
 data class ShowDeleteHistoryDialog(
-  private val effects: PublishProcessor<SideEffect<*>>,
+  private val effects: MutableSharedFlow<SideEffect<*>>,
   private val state: HistoryState,
   private val pageDao: PageDao,
   private val viewModelScope: CoroutineScope,
@@ -40,7 +40,7 @@ data class ShowDeleteHistoryDialog(
   override fun invokeWith(activity: AppCompatActivity) {
     activity.cachedComponent.inject(this)
     dialogShower.show(if (state.isInSelectionState) DeleteSelectedHistory else DeleteAllHistory, {
-      effects.offer(DeletePageItems(state, pageDao, viewModelScope))
+      effects.tryEmit(DeletePageItems(state, pageDao, viewModelScope))
     })
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/page/notes/viewmodel/NotesViewModel.kt

@@ -55,7 +55,7 @@ class NotesViewModel @Inject constructor(
     action: Action.UserClickedShowAllToggle,
     state: NotesState
   ): NotesState {
-    effects.offer(UpdateAllNotesPreference(sharedPreferenceUtil, action.isChecked))
+    effects.tryEmit(UpdateAllNotesPreference(sharedPreferenceUtil, action.isChecked))
     return state.copy(showAll = action.isChecked)
   }
 

core/src/main/java/org/kiwix/kiwixmobile/core/page/notes/viewmodel/effects/ShowDeleteNotesDialog.kt

@@ -19,8 +19,8 @@ package org.kiwix.kiwixmobile.core.page.notes.viewmodel.effects
  */
 
 import androidx.appcompat.app.AppCompatActivity
-import io.reactivex.processors.PublishProcessor
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableSharedFlow
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.PageDao
 import org.kiwix.kiwixmobile.core.extensions.ActivityExtensions.cachedComponent
@@ -31,7 +31,7 @@ import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteAllNotes
 import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteSelectedNotes
 
 data class ShowDeleteNotesDialog(
-  private val effects: PublishProcessor<SideEffect<*>>,
+  private val effects: MutableSharedFlow<SideEffect<*>>,
   private val state: NotesState,
   private val pageDao: PageDao,
   private val viewModelScope: CoroutineScope,
@@ -42,7 +42,7 @@ data class ShowDeleteNotesDialog(
     dialogShower.show(
       if (state.isInSelectionState) DeleteSelectedNotes else DeleteAllNotes,
       {
-        effects.offer(DeletePageItems(state, pageDao, viewModelScope))
+        effects.tryEmit(DeletePageItems(state, pageDao, viewModelScope))
       }
     )
   }

core/src/main/java/org/kiwix/kiwixmobile/core/page/notes/viewmodel/effects/ShowOpenNoteDialog.kt

@@ -19,7 +19,7 @@
 package org.kiwix.kiwixmobile.core.page.notes.viewmodel.effects
 
 import androidx.appcompat.app.AppCompatActivity
-import io.reactivex.processors.PublishProcessor
+import kotlinx.coroutines.flow.MutableSharedFlow
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.extensions.ActivityExtensions.cachedComponent
 import org.kiwix.kiwixmobile.core.page.adapter.Page
@@ -31,7 +31,7 @@ import org.kiwix.kiwixmobile.core.utils.dialog.DialogShower
 import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.ShowNoteDialog
 
 data class ShowOpenNoteDialog(
-  private val effects: PublishProcessor<SideEffect<*>>,
+  private val effects: MutableSharedFlow<SideEffect<*>>,
   private val page: Page,
   private val zimReaderContainer: ZimReaderContainer,
   private val dialogShower: DialogShower
@@ -40,10 +40,10 @@ data class ShowOpenNoteDialog(
     activity.cachedComponent.inject(this)
     dialogShower.show(
       ShowNoteDialog,
-      { effects.offer(OpenPage(page, zimReaderContainer)) },
+      { effects.tryEmit(OpenPage(page, zimReaderContainer)) },
       {
         val item = page as NoteListItem
-        effects.offer(OpenNote(item))
+        effects.tryEmit(OpenNote(item))
       }
     )
   }

core/src/main/java/org/kiwix/kiwixmobile/core/page/viewmodel/PageState.kt

@@ -21,6 +21,8 @@ package org.kiwix.kiwixmobile.core.page.viewmodel
 import org.kiwix.kiwixmobile.core.page.adapter.Page
 import org.kiwix.kiwixmobile.core.page.adapter.PageRelated
 import org.kiwix.kiwixmobile.core.page.bookmark.adapter.LibkiwixBookmarkItem
+import org.kiwix.kiwixmobile.core.page.history.adapter.HistoryListItem.HistoryItem
+import org.kiwix.kiwixmobile.core.page.notes.adapter.NoteListItem
 
 abstract class PageState<T : Page> {
   abstract val pageItems: List<T>
@@ -43,8 +45,12 @@ abstract class PageState<T : Page> {
       val currentItemIdentifier = if (it is LibkiwixBookmarkItem) it.url else it.id
       val pageIdentifier = if (it is LibkiwixBookmarkItem) page.url else page.id
       if (currentItemIdentifier == pageIdentifier) {
-        it.apply {
+        when (it) {
-          isSelected = !isSelected
+          is LibkiwixBookmarkItem -> it.copy(isSelected = !it.isSelected) as T
+          is HistoryItem -> it.copy(isSelected = !it.isSelected) as T
+          is NoteListItem -> it.copy(isSelected = !it.isSelected) as T
+          // For test cases only.
+          else -> it.apply { isSelected = !isSelected }
         }
       } else {
         it

core/src/main/java/org/kiwix/kiwixmobile/core/page/viewmodel/PageViewModel.kt

@@ -18,14 +18,21 @@
 
 package org.kiwix.kiwixmobile.core.page.viewmodel
 
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
-import io.reactivex.disposables.CompositeDisposable
+import kotlinx.coroutines.CoroutineDispatcher
-import io.reactivex.disposables.Disposable
-import io.reactivex.processors.PublishProcessor
-import io.reactivex.schedulers.Schedulers
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onEach
+import org.jetbrains.annotations.VisibleForTesting
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.PageDao
 import org.kiwix.kiwixmobile.core.page.adapter.Page
@@ -54,32 +61,32 @@ abstract class PageViewModel<T : Page, S : PageState<T>>(
   lateinit var alertDialogShower: AlertDialogShower
 
   private lateinit var pageViewModelClickListener: PageViewModelClickListener
+  private val _state = MutableStateFlow(initialState())
+  val state: StateFlow<S> = _state.asStateFlow()
+  val effects = MutableSharedFlow<SideEffect<*>>(extraBufferCapacity = Int.MAX_VALUE)
+  val actions = MutableSharedFlow<Action>(extraBufferCapacity = Int.MAX_VALUE)
+  private val coroutineJobs = mutableListOf<Job>()
 
-  val state: MutableLiveData<S> by lazy {
+  @VisibleForTesting
-    MutableLiveData<S>().apply {
+  fun getMutableStateForTestCases() = _state
-      value = initialState()
-    }
-  }
-
-  private val compositeDisposable = CompositeDisposable()
-  val effects = PublishProcessor.create<SideEffect<*>>()
-  val actions = PublishProcessor.create<Action>()
 
   init {
-    addDisposablesToCompositeDisposable()
+    coroutineJobs.apply {
+      add(observeActions())
+      add(observePages())
+    }
   }
 
-  private fun viewStateReducer(): Disposable =
+  private fun observeActions() =
-    actions.map { state.value?.let { value -> reduce(it, value) } }
+    actions.map { action -> reduce(action, state.value) }
-      .subscribe(state::postValue, Throwable::printStackTrace)
+      .onEach { newState -> _state.value = newState }
+      .launchIn(viewModelScope)
 
-  protected fun addDisposablesToCompositeDisposable() {
+  private fun observePages(dispatcher: CoroutineDispatcher = Dispatchers.IO) =
-    compositeDisposable.addAll(
+    pageDao.pages()
-      viewStateReducer(),
+      .flowOn(dispatcher)
-      pageDao.pages().subscribeOn(Schedulers.io())
+      .onEach { actions.tryEmit(UpdatePages(it)) }
-        .subscribe({ actions.offer(UpdatePages(it)) }, Throwable::printStackTrace)
+      .launchIn(viewModelScope)
-    )
-  }
 
   private fun reduce(action: Action, state: S): S =
     when (action) {
@@ -103,7 +110,7 @@ abstract class PageViewModel<T : Page, S : PageState<T>>(
   ): S
 
   private fun offerShowDeleteDialog(state: S): S {
-    effects.offer(createDeletePageDialogEffect(state, viewModelScope = viewModelScope))
+    effects.tryEmit(createDeletePageDialogEffect(state, viewModelScope = viewModelScope))
     return state
   }
 
@@ -117,9 +124,9 @@ abstract class PageViewModel<T : Page, S : PageState<T>>(
       return copyWithNewItems(state, state.getItemsAfterToggleSelectionOfItem(action.page))
     }
     if (::pageViewModelClickListener.isInitialized) {
-      effects.offer(pageViewModelClickListener.onItemClick(action.page))
+      effects.tryEmit(pageViewModelClickListener.onItemClick(action.page))
     } else {
-      effects.offer(OpenPage(action.page, zimReaderContainer))
+      effects.tryEmit(OpenPage(action.page, zimReaderContainer))
     }
     return state
   }
@@ -131,12 +138,15 @@ abstract class PageViewModel<T : Page, S : PageState<T>>(
   abstract fun deselectAllPages(state: S): S
 
   private fun exitFragment(state: S): S {
-    effects.offer(PopFragmentBackstack)
+    effects.tryEmit(PopFragmentBackstack)
     return state
   }
 
   override fun onCleared() {
-    compositeDisposable.clear()
+    coroutineJobs.forEach {
+      it.cancel()
+    }
+    coroutineJobs.clear()
     super.onCleared()
   }
 

core/src/test/java/org/kiwix/kiwixmobile/core/page/bookmark/viewmodel/BookmarkViewModelTest.kt

@@ -21,11 +21,9 @@ package org.kiwix.kiwixmobile.core.page.bookmark.viewmodel
 import io.mockk.clearAllMocks
 import io.mockk.every
 import io.mockk.mockk
-import io.reactivex.Flowable
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.reactive.asPublisher
 import kotlinx.coroutines.test.runTest
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.BeforeEach
@@ -44,6 +42,7 @@ import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
 import org.kiwix.kiwixmobile.core.reader.ZimReaderSource
 import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
 import org.kiwix.kiwixmobile.core.utils.dialog.AlertDialogShower
+import org.kiwix.kiwixmobile.core.utils.files.testFlow
 import org.kiwix.sharedFunctions.InstantExecutorExtension
 import java.util.UUID
 
@@ -67,9 +66,7 @@ internal class BookmarkViewModelTest {
     every { zimReaderContainer.name } returns "zimName"
     every { sharedPreferenceUtil.showBookmarksAllBooks } returns true
     every { libkiwixBookMarks.bookmarks() } returns itemsFromDb
-    every { libkiwixBookMarks.pages() } returns Flowable.fromPublisher(
+    every { libkiwixBookMarks.pages() } returns libkiwixBookMarks.bookmarks()
-      libkiwixBookMarks.bookmarks().asPublisher()
-    )
     viewModel =
       BookmarkViewModel(libkiwixBookMarks, zimReaderContainer, sharedPreferenceUtil).apply {
         alertDialogShower = dialogShower
@@ -106,13 +103,24 @@ internal class BookmarkViewModelTest {
   }
 
   @Test
-  fun `offerUpdateToShowAllToggle offers UpdateAllBookmarksPreference`() {
+  fun `offerUpdateToShowAllToggle offers UpdateAllBookmarksPreference`() = runTest {
-    viewModel.effects.test().also {
+    testFlow(
+      flow = viewModel.effects,
+      triggerAction = {
         viewModel.offerUpdateToShowAllToggle(
           Action.UserClickedShowAllToggle(false),
           bookmarkState()
         )
-    }.assertValues(UpdateAllBookmarksPreference(sharedPreferenceUtil, false))
+      },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(
+          UpdateAllBookmarksPreference(
+            sharedPreferenceUtil,
+            false
+          )
+        )
+      }
+    )
   }
 
   @Test

core/src/test/java/org/kiwix/kiwixmobile/core/page/bookmark/viewmodel/effects/ShowDeleteBookmarksDialogTest.kt

@@ -22,9 +22,9 @@ import io.mockk.every
 import io.mockk.mockk
 import io.mockk.slot
 import io.mockk.verify
-import io.reactivex.processors.PublishProcessor
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.runBlocking
 import org.junit.jupiter.api.Test
 import org.kiwix.kiwixmobile.core.base.SideEffect
@@ -40,7 +40,7 @@ import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteSelectedBookmar
 import java.util.UUID
 
 internal class ShowDeleteBookmarksDialogTest {
-  val effects = mockk<PublishProcessor<SideEffect<*>>>(relaxed = true)
+  val effects = mockk<MutableSharedFlow<SideEffect<*>>>(relaxed = true)
   private val newBookmarksDao = mockk<NewBookmarksDao>()
   val activity = mockk<CoreMainActivity>()
   private val dialogShower = mockk<DialogShower>(relaxed = true)
@@ -61,7 +61,7 @@ internal class ShowDeleteBookmarksDialogTest {
     showDeleteBookmarksDialog.invokeWith(activity)
     verify { dialogShower.show(any(), capture(lambdaSlot)) }
     lambdaSlot.captured.invoke()
-    verify { effects.offer(DeletePageItems(bookmarkState(), newBookmarksDao, viewModelScope)) }
+    verify { effects.tryEmit(DeletePageItems(bookmarkState(), newBookmarksDao, viewModelScope)) }
   }
 
   private fun mockkActivityInjection(showDeleteBookmarksDialog: ShowDeleteBookmarksDialog) {

core/src/test/java/org/kiwix/kiwixmobile/core/page/history/viewmodel/HistoryViewModelTest.kt

@@ -3,12 +3,9 @@ package org.kiwix.kiwixmobile.core.page.history.viewmodel
 import io.mockk.clearAllMocks
 import io.mockk.every
 import io.mockk.mockk
-import io.reactivex.plugins.RxJavaPlugins
-import io.reactivex.processors.PublishProcessor
-import io.reactivex.schedulers.Schedulers
-import io.reactivex.schedulers.TestScheduler
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.test.runTest
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.BeforeEach
@@ -27,8 +24,8 @@ import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
 import org.kiwix.kiwixmobile.core.reader.ZimReaderSource
 import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
 import org.kiwix.kiwixmobile.core.utils.dialog.AlertDialogShower
+import org.kiwix.kiwixmobile.core.utils.files.testFlow
 import org.kiwix.sharedFunctions.InstantExecutorExtension
-import org.kiwix.sharedFunctions.setScheduler
 
 @ExtendWith(InstantExecutorExtension::class)
 internal class HistoryViewModelTest {
@@ -39,16 +36,10 @@ internal class HistoryViewModelTest {
   private val viewModelScope = CoroutineScope(Dispatchers.IO)
 
   private lateinit var viewModel: HistoryViewModel
-  private val testScheduler = TestScheduler()
   private val zimReaderSource: ZimReaderSource = mockk()
 
-  init {
+  private val itemsFromDb: MutableSharedFlow<List<Page>> =
-    setScheduler(testScheduler)
+    MutableSharedFlow<List<Page>>(0)
-    RxJavaPlugins.setIoSchedulerHandler { Schedulers.trampoline() }
-  }
-
-  private val itemsFromDb: PublishProcessor<List<Page>> =
-    PublishProcessor.create()
 
   @BeforeEach
   fun init() {
@@ -89,13 +80,21 @@ internal class HistoryViewModelTest {
   }
 
   @Test
-  fun `offerUpdateToShowAllToggle offers UpdateAllHistoryPreference`() {
+  fun `offerUpdateToShowAllToggle offers UpdateAllHistoryPreference`() = runTest {
-    viewModel.effects.test().also {
+    testFlow(
+      flow = viewModel.effects,
+      triggerAction = {
         viewModel.offerUpdateToShowAllToggle(
           UserClickedShowAllToggle(false),
           historyState()
         )
-    }.assertValues(UpdateAllHistoryPreference(sharedPreferenceUtil, false))
+      },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(
+          UpdateAllHistoryPreference(sharedPreferenceUtil, false)
+        )
+      }
+    )
   }
 
   @Test

core/src/test/java/org/kiwix/kiwixmobile/core/page/history/viewmodel/effects/ShowDeleteHistoryDialogTest.kt

@@ -4,9 +4,9 @@ import io.mockk.every
 import io.mockk.mockk
 import io.mockk.slot
 import io.mockk.verify
-import io.reactivex.processors.PublishProcessor
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.runBlocking
 import org.junit.jupiter.api.Test
 import org.kiwix.kiwixmobile.core.base.SideEffect
@@ -20,7 +20,7 @@ import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteAllHistory
 import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.DeleteSelectedHistory
 
 internal class ShowDeleteHistoryDialogTest {
-  val effects = mockk<PublishProcessor<SideEffect<*>>>(relaxed = true)
+  val effects = mockk<MutableSharedFlow<SideEffect<*>>>(relaxed = true)
   private val historyDao = mockk<HistoryDao>()
   val activity = mockk<CoreMainActivity>()
   private val dialogShower = mockk<DialogShower>(relaxed = true)
@@ -42,7 +42,7 @@ internal class ShowDeleteHistoryDialogTest {
       showDeleteHistoryDialog.invokeWith(activity)
       verify { dialogShower.show(any(), capture(lambdaSlot)) }
       lambdaSlot.captured.invoke()
-      verify { effects.offer(DeletePageItems(historyState(), historyDao, viewModelScope)) }
+      verify { effects.tryEmit(DeletePageItems(historyState(), historyDao, viewModelScope)) }
     }
 
   @Test

core/src/test/java/org/kiwix/kiwixmobile/core/page/viewmodel/PageViewModelTest.kt

@@ -18,18 +18,16 @@
 
 package org.kiwix.kiwixmobile.core.page.viewmodel
 
-import com.jraska.livedata.test
 import io.mockk.clearAllMocks
 import io.mockk.every
 import io.mockk.mockk
-import io.reactivex.plugins.RxJavaPlugins
-import io.reactivex.processors.PublishProcessor
-import io.reactivex.schedulers.Schedulers
-import io.reactivex.schedulers.TestScheduler
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.advanceUntilIdle
 import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.runTest
 import kotlinx.coroutines.test.setMain
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.AfterEach
@@ -40,22 +38,22 @@ import org.kiwix.kiwixmobile.core.dao.PageDao
 import org.kiwix.kiwixmobile.core.page.PageImpl
 import org.kiwix.kiwixmobile.core.page.adapter.Page
 import org.kiwix.kiwixmobile.core.page.pageState
+import org.kiwix.kiwixmobile.core.page.viewmodel.Action.UpdatePages
+import org.kiwix.kiwixmobile.core.page.viewmodel.Action.Filter
 import org.kiwix.kiwixmobile.core.page.viewmodel.Action.Exit
 import org.kiwix.kiwixmobile.core.page.viewmodel.Action.ExitActionModeMenu
-import org.kiwix.kiwixmobile.core.page.viewmodel.Action.Filter
+import org.kiwix.kiwixmobile.core.page.viewmodel.Action.UserClickedShowAllToggle
-import org.kiwix.kiwixmobile.core.page.viewmodel.Action.OnItemClick
-import org.kiwix.kiwixmobile.core.page.viewmodel.Action.OnItemLongClick
-import org.kiwix.kiwixmobile.core.page.viewmodel.Action.UpdatePages
 import org.kiwix.kiwixmobile.core.page.viewmodel.Action.UserClickedDeleteButton
 import org.kiwix.kiwixmobile.core.page.viewmodel.Action.UserClickedDeleteSelectedPages
-import org.kiwix.kiwixmobile.core.page.viewmodel.Action.UserClickedShowAllToggle
+import org.kiwix.kiwixmobile.core.page.viewmodel.Action.OnItemClick
+import org.kiwix.kiwixmobile.core.page.viewmodel.Action.OnItemLongClick
 import org.kiwix.kiwixmobile.core.page.viewmodel.effects.OpenPage
 import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
 import org.kiwix.kiwixmobile.core.reader.ZimReaderSource
 import org.kiwix.kiwixmobile.core.search.viewmodel.effects.PopFragmentBackstack
 import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
+import org.kiwix.kiwixmobile.core.utils.files.testFlow
 import org.kiwix.sharedFunctions.InstantExecutorExtension
-import org.kiwix.sharedFunctions.setScheduler
 
 @OptIn(ExperimentalCoroutinesApi::class)
 @ExtendWith(InstantExecutorExtension::class)
@@ -65,14 +63,8 @@ internal class PageViewModelTest {
   private val sharedPreferenceUtil: SharedPreferenceUtil = mockk()
 
   private lateinit var viewModel: TestablePageViewModel
-  private val testScheduler = TestScheduler()
+  private val itemsFromDb: MutableSharedFlow<List<Page>> =
-  private val itemsFromDb: PublishProcessor<List<Page>> =
+    MutableSharedFlow<List<Page>>(0)
-    PublishProcessor.create()
-
-  init {
-    setScheduler(testScheduler)
-    RxJavaPlugins.setIoSchedulerHandler { Schedulers.trampoline() }
-  }
 
   @BeforeEach
   fun init() {
@@ -91,73 +83,139 @@ internal class PageViewModelTest {
   }
 
   @Test
-  fun `initial state is Initialising`() {
+  fun `initial state is Initialising`() = runTest {
-    viewModel.state.test().assertValue(pageState())
+    testFlow(
+      flow = viewModel.state,
+      triggerAction = {},
+      assert = { assertThat(awaitItem()).isEqualTo(pageState()) }
+    )
   }
 
   @Test
-  fun `Exit calls PopFragmentBackstack`() {
+  fun `Exit calls PopFragmentBackstack`() = runTest {
-    viewModel.effects.test().also { viewModel.actions.offer(Exit) }
+    testFlow(
-      .assertValue(PopFragmentBackstack)
+      flow = viewModel.effects,
-    viewModel.state.test().assertValue(pageState())
+      triggerAction = { viewModel.actions.tryEmit(Exit) },
+      assert = { assertThat(awaitItem()).isEqualTo(PopFragmentBackstack) }
+    )
+    testFlow(
+      flow = viewModel.state,
+      triggerAction = {},
+      assert = { assertThat(awaitItem()).isEqualTo(pageState()) }
+    )
   }
 
   @Test
-  fun `ExitActionModeMenu calls deslectAllPages`() {
+  fun `ExitActionModeMenu calls deslectAllPages`() = runTest {
-    viewModel.actions.offer(ExitActionModeMenu)
+    testFlow(
-    viewModel.state.test().assertValue(TestablePageState(searchTerm = "deselectAllPagesCalled"))
+      flow = viewModel.state,
+      triggerAction = { viewModel.actions.tryEmit(ExitActionModeMenu) },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(TestablePageState(searchTerm = ""))
+        assertThat(awaitItem())
+          .isEqualTo(TestablePageState(searchTerm = "deselectAllPagesCalled"))
+      }
+    )
   }
 
   @Test
-  fun `UserClickedShowAllToggle calls offerUpdateToShowAllToggle`() {
+  fun `UserClickedShowAllToggle calls offerUpdateToShowAllToggle`() = runTest {
-    val action = UserClickedShowAllToggle(true)
+    testFlow(
-    viewModel.actions.offer(action)
+      flow = viewModel.state,
-    viewModel.state.test()
+      triggerAction = {
-      .assertValue(TestablePageState(searchTerm = "offerUpdateToShowAllToggleCalled"))
+        viewModel.actions.tryEmit(UserClickedShowAllToggle(true))
+      },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(TestablePageState(searchTerm = ""))
+        assertThat(awaitItem())
+          .isEqualTo(TestablePageState(searchTerm = "offerUpdateToShowAllToggleCalled"))
+      }
+    )
   }
 
   @Test
-  fun `UserClickedDeleteButton calls createDeletePageDialogEffect`() {
+  fun `UserClickedDeleteButton calls createDeletePageDialogEffect`() = runTest {
-    viewModel.actions.offer(UserClickedDeleteButton)
+    viewModel.actions.tryEmit(UserClickedDeleteButton)
+    advanceUntilIdle()
     assertThat(viewModel.createDeletePageDialogEffectCalled).isEqualTo(true)
   }
 
   @Test
-  fun `UserClickedDeleteSelectedPages calls createDeletePageDialogEffect`() {
+  fun `UserClickedDeleteSelectedPages calls createDeletePageDialogEffect`() = runTest {
-    viewModel.actions.offer(UserClickedDeleteSelectedPages)
+    viewModel.actions.tryEmit(UserClickedDeleteSelectedPages)
+    advanceUntilIdle()
     assertThat(viewModel.createDeletePageDialogEffectCalled).isEqualTo(true)
   }
 
   @Test
-  internal fun `OnItemClick selects item if one is selected`() {
+  internal fun `OnItemClick selects item if one is selected`() = runTest {
     val zimReaderSource: ZimReaderSource = mockk()
+    testFlow(
+      viewModel.state,
+      triggerAction = {
         val page = PageImpl(isSelected = true, zimReaderSource = zimReaderSource)
-    viewModel.state.postValue(TestablePageState(listOf(page)))
+        viewModel.getMutableStateForTestCases().value = TestablePageState(listOf(page))
-    viewModel.actions.offer(OnItemClick(page))
+        viewModel.actions.tryEmit(OnItemClick(page))
-    viewModel.state.test()
+      },
-      .assertValue(TestablePageState(listOf(PageImpl(zimReaderSource = zimReaderSource))))
+      assert = {
+        assertThat(awaitItem()).isEqualTo(TestablePageState())
+        assertThat(awaitItem())
+          .isEqualTo(
+            TestablePageState(
+              listOf(PageImpl(zimReaderSource = zimReaderSource))
+            )
+          )
+      }
+    )
   }
 
   @Test
-  internal fun `OnItemClick offers OpenPage if none is selected`() {
+  internal fun `OnItemClick offers OpenPage if none is selected`() = runTest {
     val zimReaderSource: ZimReaderSource = mockk()
-    viewModel.state.postValue(
+    testFlow(
+      viewModel.effects,
+      triggerAction = {
+        viewModel.getMutableStateForTestCases().value =
+          TestablePageState(listOf(PageImpl(zimReaderSource = zimReaderSource)))
+        viewModel.actions.tryEmit(OnItemClick(PageImpl(zimReaderSource = zimReaderSource)))
+      },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(
+          OpenPage(
+            PageImpl(zimReaderSource = zimReaderSource),
+            zimReaderContainer
+          )
+        )
+      }
+    )
+    testFlow(
+      viewModel.state,
+      triggerAction = {
+        viewModel.getMutableStateForTestCases().value =
+          TestablePageState(listOf(PageImpl(zimReaderSource = zimReaderSource)))
+        viewModel.actions.tryEmit(OnItemClick(PageImpl(zimReaderSource = zimReaderSource)))
+      },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(
           TestablePageState(listOf(PageImpl(zimReaderSource = zimReaderSource)))
         )
-    viewModel.effects.test()
+      }
-      .also { viewModel.actions.offer(OnItemClick(PageImpl(zimReaderSource = zimReaderSource))) }
+    )
-      .assertValue(OpenPage(PageImpl(zimReaderSource = zimReaderSource), zimReaderContainer))
-    viewModel.state.test()
-      .assertValue(TestablePageState(listOf(PageImpl(zimReaderSource = zimReaderSource))))
   }
 
   @Test
-  internal fun `OnItemLongClick selects item if none is selected`() {
+  internal fun `OnItemLongClick selects item if none is selected`() = runTest {
     val zimReaderSource: ZimReaderSource = mockk()
     val page = PageImpl(zimReaderSource = zimReaderSource)
-    viewModel.state.postValue(TestablePageState(listOf(page)))
+    testFlow(
-    viewModel.actions.offer(OnItemLongClick(page))
+      viewModel.state,
-    viewModel.state.test().assertValue(
+      triggerAction = {
+        viewModel.getMutableStateForTestCases().value = TestablePageState(listOf(page))
+        viewModel.actions.tryEmit(OnItemLongClick(page))
+      },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(TestablePageState())
+        assertThat(awaitItem()).isEqualTo(
           TestablePageState(
             listOf(
               PageImpl(
@@ -168,18 +226,30 @@ internal class PageViewModelTest {
           )
         )
       }
-
+    )
-  @Test
-  fun `Filter calls updatePagesBasedOnFilter`() {
-    viewModel.actions.offer(Filter("Called"))
-    viewModel.state.test()
-      .assertValue(TestablePageState(searchTerm = "updatePagesBasedOnFilterCalled"))
   }
 
   @Test
-  fun `UpdatePages calls updatePages`() {
+  fun `Filter calls updatePagesBasedOnFilter`() = runTest {
-    viewModel.actions.offer(UpdatePages(emptyList()))
+    testFlow(
-    viewModel.state.test()
+      viewModel.state,
-      .assertValue(TestablePageState(searchTerm = "updatePagesCalled"))
+      triggerAction = { viewModel.actions.tryEmit(Filter("Called")) },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(TestablePageState())
+        assertThat(awaitItem()).isEqualTo(TestablePageState(searchTerm = "updatePagesBasedOnFilterCalled"))
+      }
+    )
+  }
+
+  @Test
+  fun `UpdatePages calls updatePages`() = runTest {
+    testFlow(
+      viewModel.state,
+      triggerAction = { viewModel.actions.tryEmit(UpdatePages(emptyList())) },
+      assert = {
+        assertThat(awaitItem()).isEqualTo(TestablePageState())
+        assertThat(awaitItem()).isEqualTo(TestablePageState(searchTerm = "updatePagesCalled"))
+      }
+    )
   }
 }

core/src/test/java/org/kiwix/kiwixmobile/core/utils/files/FileSearchTest.kt

@@ -31,7 +31,6 @@ import io.mockk.clearMocks
 import io.mockk.every
 import io.mockk.mockk
 import io.mockk.mockkStatic
-import io.reactivex.schedulers.Schedulers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.test.TestScope
@@ -41,8 +40,6 @@ import org.junit.jupiter.api.AfterAll
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
-import org.kiwix.sharedFunctions.resetSchedulers
-import org.kiwix.sharedFunctions.setScheduler
 import java.io.File
 
 class FileSearchTest {
@@ -54,10 +51,6 @@ class FileSearchTest {
   private val storageDevice: StorageDevice = mockk()
   private val scanningProgressListener: ScanningProgressListener = mockk()
 
-  init {
-    setScheduler(Schedulers.trampoline())
-  }
-
   @BeforeEach
   fun init() {
     clearMocks(context, externalStorageDirectory, contentResolver, storageDevice)
@@ -78,7 +71,6 @@ class FileSearchTest {
   @AfterAll
   fun teardown() {
     deleteTempDirectory()
-    resetSchedulers()
   }
 
   @Nested