FixIllegalStateExceptionConcurrentTransaction

CHANGELOG.md

@@ -12,6 +12,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - This changelog file
+- Fix a bug where a fragment that we want to hide is not added to the fragment manager,
+causing an IllegalStateException due to multiple fragment transactions occurring simultaneously 
+because of the executePendingTransactions() method call
 
 ### Changed
 

gradle/libs.toml

@@ -13,9 +13,11 @@ androidXArchCoreTesting = "androidx.arch.core:core-testing:2.2.0"
 androidXFragmentTesting = "androidx.fragment:fragment-testing:1.8.0"
 androidXTestCoreKtx = "androidx.test:core-ktx:1.4.0"
 androidXTestExtJunit = "androidx.test.ext:junit:1.1.3"
+androidXTestRunner = "androidx.test:runner:1.5.2"
 junit = "junit:junit:4.13.2"
 robolectric = "org.robolectric:robolectric:4.12.2"
 truth = "com.google.truth:truth:1.4.2"
+espressoTest = "androidx.test.espresso:espresso-core:3.6.0"
 
 [versions]
 kotlin = "2.0.0"

medusalib/build.gradle

@@ -57,6 +57,14 @@ dependencies {
  testImplementation libs.junit
  testImplementation libs.robolectric
  testImplementation libs.truth
+
+ androidTestImplementation libs.androidXTestExtJunit
+ androidTestImplementation libs.androidXTestRunner
+ debugImplementation libs.androidXFragmentTesting
+ androidTestImplementation libs.truth
+ androidTestImplementation libs.junit
+ androidTestImplementation libs.espressoTest
+
 }
 
 repositories {

medusalib/src/androidTest/java/com/trendyol/medusalib/TestChildFragment.kt

@@ -0,0 +1,36 @@
+package com.trendyol.medusalib
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+import androidx.fragment.app.Fragment
+
+private const val KEY_TITLE = "title"
+
+class TestChildFragment : Fragment() {
+
+ var onFragmentVisibleAgain: (() -> Unit)? = null
+
+ override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+ return TextView(requireContext()).apply {
+ text = requireArguments().getString(KEY_TITLE)
+ }
+ }
+
+ override fun onHiddenChanged(hidden: Boolean) {
+ super.onHiddenChanged(hidden)
+ if (hidden.not() && view != null) {
+ onFragmentVisibleAgain?.invoke()
+ }
+ }
+
+ companion object {
+ fun newInstance(title: String): TestChildFragment {
+ return TestChildFragment().apply {
+ arguments = Bundle().apply { putString(KEY_TITLE, title) }
+ }
+ }
+ }
+}

medusalib/src/androidTest/java/com/trendyol/medusalib/TestParentFragment.kt

@@ -0,0 +1,19 @@
+package com.trendyol.medusalib
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.FrameLayout
+import androidx.fragment.app.Fragment
+
+class TestParentFragment : Fragment() {
+
+ override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+ return FrameLayout(requireContext()).apply { id = CONTAINER_ID }
+ }
+
+ companion object {
+ const val CONTAINER_ID = 1_000
+ }
+}

medusalib/src/androidTest/java/com/trendyol/medusalib/navigator/ConcurrentTransactionTest.kt

@@ -0,0 +1,83 @@
+package com.trendyol.medusalib.navigator
+
+import androidx.fragment.app.testing.FragmentScenario
+import androidx.fragment.app.testing.launchFragmentInContainer
+import androidx.fragment.app.testing.withFragment
+import androidx.lifecycle.Lifecycle
+import androidx.test.espresso.Espresso.onView
+import androidx.test.espresso.assertion.ViewAssertions.matches
+import androidx.test.espresso.matcher.ViewMatchers.isDisplayed
+import androidx.test.espresso.matcher.ViewMatchers.withText
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.trendyol.medusalib.TestChildFragment
+import com.trendyol.medusalib.TestParentFragment
+import com.trendyol.medusalib.navigator.transaction.NavigatorTransaction
+import com.trendyol.medusalib.navigator.transaction.TransactionType
+import org.junit.Test
+import org.junit.runner.RunWith
+import java.util.concurrent.CountDownLatch
+
+
+@RunWith(AndroidJUnit4::class)
+class ConcurrentTransactionTest {
+
+ @Test
+ fun givenNavigatorWithShowAndHideWhenFragmentResetsTheCurrentTabAndStartsAnotherFragmentThenItMustNotThrowAnyExceptions() {
+ // Given
+ val transaction = CountDownLatch(1)
+ var caughtException: Throwable? = null
+ var navigator: Navigator? = null
+ val scenario = launchFragmentInContainer<TestParentFragment>(
+ initialState = Lifecycle.State.INITIALIZED
+ )
+ scenario.moveToState(Lifecycle.State.RESUMED)
+ val rootFragment = TestChildFragment.newInstance("Root")
+ val expectedFragment = TestChildFragment.newInstance("ExpectedFragment")
+
+ scenario.withFragment { navigator = createNavigator(rootFragment = rootFragment) }
+ scenario.moveToState(Lifecycle.State.RESUMED)
+
+ // When
+ rootFragment.onFragmentVisibleAgain = {
+ resetTabAndStartFragment(navigator!!, expectedFragment)
+ .onSuccess { transaction.countDown() }
+ .onFailure {
+ caughtException = it
+ transaction.countDown()
+ }
+ }
+ scenario.startAndDismissAFragment(navigator!!)
+
+ transaction.await()
+ caughtException?.let { throw it }
+ scenario.moveToState(Lifecycle.State.RESUMED)
+ onView(withText("ExpectedFragment")).check(matches(isDisplayed()))
+ }
+
+ private fun FragmentScenario<TestParentFragment>.startAndDismissAFragment(navigator: Navigator) {
+ onFragment { navigator.start(TestChildFragment.newInstance("SecondFragment")) }
+ moveToState(Lifecycle.State.RESUMED)
+ onFragment { navigator.goBack() }
+ }
+
+ private fun resetTabAndStartFragment(
+ navigator: Navigator,
+ expectedFragment: TestChildFragment
+ ): Result<Unit> {
+ return runCatching {
+ navigator.resetCurrentTab(true)
+ navigator.start(expectedFragment)
+ }
+ }
+
+ private fun TestParentFragment.createNavigator(rootFragment: TestChildFragment): MultipleStackNavigator {
+ return MultipleStackNavigator(
+ fragmentManager = this.childFragmentManager,
+ containerId = TestParentFragment.CONTAINER_ID,
+ rootFragmentProvider = listOf({ rootFragment }),
+ navigatorConfiguration = NavigatorConfiguration(
+ defaultNavigatorTransaction = NavigatorTransaction(TransactionType.SHOW_HIDE)
+ )
+ ).apply { this.initialize(null) }
+ }
+}

medusalib/src/main/java/com/trendyol/medusalib/navigator/MultipleStackNavigator.kt

@@ -7,6 +7,7 @@ import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.MutableLiveData
 import com.trendyol.medusalib.navigator.controller.FragmentManagerController
+import com.trendyol.medusalib.navigator.controller.StagedFragmentHolder
 import com.trendyol.medusalib.navigator.data.FragmentData
 import com.trendyol.medusalib.navigator.data.StackItem
 import com.trendyol.medusalib.navigator.tag.TagCreator
@@ -28,7 +29,8 @@ open class MultipleStackNavigator(
  private val fragmentManagerController = FragmentManagerController(
  fragmentManager,
  containerId,
- navigatorConfiguration.defaultNavigatorTransaction
+ navigatorConfiguration.defaultNavigatorTransaction,
+ StagedFragmentHolder(mutableMapOf())
  )
 
  private val fragmentStackStateMapper = FragmentStackStateMapper()
@@ -77,10 +79,13 @@ open class MultipleStackNavigator(
  fragmentStackState.notifyStackItemAddToCurrentTab(
  StackItem(
  fragmentTag = createdTag,
- groupName = fragmentGroupName
- )
+ groupName = fragmentGroupName,
+ ),
+ )
+ fragment.observeFragmentLifecycle(
+ ::onFragmentViewCreated,
+ ::onFragmentDestroy
  )
- notifyFragmentDestinationChange(fragment)
  }
 
  override fun goBack() {
@@ -144,17 +149,27 @@ open class MultipleStackNavigator(
  val createdTag = tagCreator.create(rootFragment)
  val rootFragmentData = FragmentData(rootFragment, createdTag)
  fragmentStackState.switchTab(currentTabIndex)
- fragmentStackState.notifyStackItemAdd(currentTabIndex, StackItem(fragmentTag = createdTag))
+ fragmentStackState.notifyStackItemAdd(
+ currentTabIndex,
+ StackItem(fragmentTag = createdTag),
+ )
  fragmentManagerController.addFragment(rootFragmentData)
- notifyFragmentDestinationChange(rootFragment)
+
+ rootFragment.observeFragmentLifecycle(
+ onViewCreated = ::onFragmentViewCreated,
+ onFragmentDestroy = ::onFragmentDestroy
+ )
  } else {
  val upperFragmentTag: String = getCurrentFragmentTag()
  val upperFragment: Fragment? = fragmentManagerController.getFragment(upperFragmentTag)
 
  val newDestination: Fragment = upperFragment ?: getRootFragment(currentTabIndex)
  val newDestinationTag: String = tagCreator.create(newDestination)
 
- notifyFragmentDestinationChange(newDestination)
+ newDestination.observeFragmentLifecycle(
+ onViewCreated = ::onFragmentViewCreated,
+ onFragmentDestroy = ::onFragmentDestroy
+ )
  fragmentManagerController.enableFragment(newDestinationTag)
  }
  }
@@ -163,6 +178,7 @@ open class MultipleStackNavigator(
  clearAllFragments()
  fragmentStackState.clear()
  initializeStackState()
+
  }
 
  override fun resetWithFragmentProvider(rootFragmentProvider: List<() -> Fragment>) {
@@ -237,14 +253,20 @@ open class MultipleStackNavigator(
  val stackItem = StackItem(fragmentTag = createdTag)
 
  fragmentStackState.setStackCount(rootFragmentProvider.size)
- fragmentStackState.notifyStackItemAdd(tabIndex = initialTabIndex, stackItem = stackItem)
+ fragmentStackState.notifyStackItemAdd(
+ tabIndex = initialTabIndex,
+ stackItem = stackItem,
+ )
  fragmentStackState.switchTab(initialTabIndex)
 
  val rootFragmentTag = fragmentStackState.peekItem(initialTabIndex).fragmentTag
  val rootFragmentData = FragmentData(rootFragment, rootFragmentTag)
  fragmentManagerController.addFragment(rootFragmentData)
  navigatorListener?.onTabChanged(navigatorConfiguration.initialTabIndex)
- notifyFragmentDestinationChange(rootFragment)
+ rootFragment.observeFragmentLifecycle(
+ ::onFragmentViewCreated,
+ ::onFragmentDestroy
+ )
  }
 
  private fun loadStackStateFromSavedState(savedState: Bundle) {
@@ -271,13 +293,29 @@ open class MultipleStackNavigator(
  val rootFragmentData = FragmentData(rootFragment, createdTag)
  fragmentStackState.notifyStackItemAdd(
  fragmentStackState.getSelectedTabIndex(),
- StackItem(createdTag)
+ StackItem(createdTag),
  )
  fragmentManagerController.addFragment(rootFragmentData)
- notifyFragmentDestinationChange(rootFragment)
+ rootFragment.observeFragmentLifecycle(
+ onViewCreated = ::onFragmentViewCreated,
+ onFragmentDestroy = ::onFragmentDestroy
+ )
  } else {
  fragmentManagerController.enableFragment(upperFragmentTag)
- notifyFragmentDestinationChange(upperFragment)
+ upperFragment.observeFragmentLifecycle(
+ onViewCreated = ::onFragmentViewCreated,
+ onFragmentDestroy = ::onFragmentDestroy
+ )
+ }
+ }
+
+ private fun onFragmentViewCreated(fragment: Fragment) {
+ destinationChangeLiveData.value = fragment
+ }
+
+ private fun onFragmentDestroy(fragment: Fragment) {
+ if (destinationChangeLiveData.value == fragment) {
+ destinationChangeLiveData.value = null
  }
  }
 
@@ -321,28 +359,34 @@ open class MultipleStackNavigator(
  return true
  }
 
- private fun notifyFragmentDestinationChange(fragment: Fragment) {
- fragment.lifecycle.addObserver(object: DefaultLifecycleObserver {
+ private fun Fragment.observeFragmentLifecycle(
+ onViewCreated: (Fragment) -> Unit,
+ onFragmentDestroy: (Fragment) -> Unit
+ ) {
+ this.lifecycle.addObserver(object : DefaultLifecycleObserver {
  override fun onStart(owner: LifecycleOwner) {
+ super.onStart(owner)
  owner.lifecycle.removeObserver(this)
- fragment.viewLifecycleOwner.lifecycle.addObserver(
- object : DefaultLifecycleObserver {
- override fun onCreate(owner: LifecycleOwner) {
- destinationChangeLiveData.value = fragment
- }
-
- override fun onDestroy(owner: LifecycleOwner) {
- if (destinationChangeLiveData.value == fragment) {
- destinationChangeLiveData.value = null
+ val fragment = this@observeFragmentLifecycle
+ fragment
+ .viewLifecycleOwner
+ .lifecycle
+ .addObserver(
+ object : DefaultLifecycleObserver {
+ override fun onCreate(owner: LifecycleOwner) {
+ onViewCreated(fragment)
+ }
+ override fun onDestroy(owner: LifecycleOwner) {
+ onFragmentDestroy(fragment)
+ owner.lifecycle.removeObserver(this)
  }
- owner.lifecycle.removeObserver(this)
  }
- }
- )
+ )
  }
  })
  }
 
+
  override fun onSaveInstanceState(outState: Bundle) {
  outState.putBundle(MEDUSA_STACK_STATE_KEY, fragmentStackStateMapper.toBundle(fragmentStackState))
  }