From 6f79b75f69b21aef17f5ed5cad5c846cd995ee0a Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 20:33:20 +0700
Subject: [PATCH 01/21] refactor

---
 .../java/com/hoc/flowmvi/ui/main/MainVM.kt    | 29 +++++----------
 .../com/hoc/flowmvi/mvi_base/MviViewModel.kt  | 36 ++++++++++++++++++-
 2 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
index 5018d79c..5c291d67 100644
--- a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
+++ b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
@@ -1,19 +1,15 @@
 package com.hoc.flowmvi.ui.main
 
 import android.util.Log
-import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
-import com.hoc.flowmvi.core.unit
 import com.hoc.flowmvi.domain.usecase.GetUsersUseCase
 import com.hoc.flowmvi.domain.usecase.RefreshGetUsersUseCase
 import com.hoc.flowmvi.domain.usecase.RemoveUserUseCase
-import com.hoc.flowmvi.mvi_base.MviViewModel
+import com.hoc.flowmvi.mvi_base.BaseMviViewModel
 import com.hoc081098.flowext.flatMapFirst
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.FlowPreview
-import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asFlow
@@ -29,7 +25,6 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.onStart
-import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.scan
 import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.flow.stateIn
@@ -41,20 +36,16 @@ class MainVM(
   private val getUsersUseCase: GetUsersUseCase,
   private val refreshGetUsers: RefreshGetUsersUseCase,
   private val removeUser: RemoveUserUseCase,
-) : ViewModel(), MviViewModel<ViewIntent, ViewState, SingleEvent> {
-  private val _eventChannel = Channel<SingleEvent>(Channel.BUFFERED)
-  private val _intentFlow = MutableSharedFlow<ViewIntent>(extraBufferCapacity = 64)
+) : BaseMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 
   override val viewState: StateFlow<ViewState>
-  override val singleEvent: Flow<SingleEvent> get() = _eventChannel.receiveAsFlow()
-  override fun processIntent(intent: ViewIntent) = _intentFlow.tryEmit(intent).unit
 
   init {
     val initialVS = ViewState.initial()
 
     viewState = merge(
-      _intentFlow.filterIsInstance<ViewIntent.Initial>().take(1),
-      _intentFlow.filterNot { it is ViewIntent.Initial }
+      intentFlow.filterIsInstance<ViewIntent.Initial>().take(1),
+      intentFlow.filterNot { it is ViewIntent.Initial }
     )
       .toPartialChangeFlow()
       .sendSingleEvent()
@@ -82,7 +73,7 @@ class MainVM(
         is PartialChange.GetUser.Data -> return@onEach
         PartialChange.Refresh.Loading -> return@onEach
       }
-      _eventChannel.send(event)
+      sendEvent(event)
     }
   }
 
@@ -110,18 +101,18 @@ class MainVM(
 
       return merge(
         filterIsInstance<ViewIntent.Initial>()
-          .logIntent()
+          .log("Intent")
           .flatMapConcat { getUserChanges },
         filterIsInstance<ViewIntent.Refresh>()
           .filter { viewState.value.let { !it.isLoading && it.error === null } }
-          .logIntent()
+          .log("Intent")
           .flatMapFirst { refreshChanges },
         filterIsInstance<ViewIntent.Retry>()
           .filter { viewState.value.error != null }
-          .logIntent()
+          .log("Intent")
           .flatMapFirst { getUserChanges },
         filterIsInstance<ViewIntent.RemoveUser>()
-          .logIntent()
+          .log("Intent")
           .map { it.user }
           .flatMapMerge { userItem ->
             flow {
@@ -139,8 +130,6 @@ class MainVM(
           }
       )
     }
-
-  private fun <T : ViewIntent> Flow<T>.logIntent() = onEach { Log.d("MainVM", "## Intent: $it") }
 }
 
 private fun <T> defer(flowFactory: () -> Flow<T>): Flow<T> = flow { emitAll(flowFactory()) }
diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index cf046f03..38dcb5bf 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -1,7 +1,13 @@
 package com.hoc.flowmvi.mvi_base
 
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.receiveAsFlow
 
 /**
  * Object that will subscribes to a MviView's [MviIntent]s,
@@ -16,5 +22,33 @@ interface MviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> {
 
   val singleEvent: Flow<E>
 
-  fun processIntent(intent: I)
+  suspend fun processIntent(intent: I)
+}
+
+abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
+  MviViewModel<I, S, E>, ViewModel() {
+  private val tag by lazy { this::class.java.simpleName.take(23) }
+
+  private val eventChannel = Channel<E>(Channel.UNLIMITED)
+  private val intentMutableFlow = MutableSharedFlow<I>(extraBufferCapacity = SubscriberBufferSize)
+
+  override val singleEvent: Flow<E> get() = eventChannel.receiveAsFlow()
+  override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
+
+  protected suspend fun sendEvent(event: E) = eventChannel.send(event)
+  protected val intentFlow: Flow<I> get() = intentMutableFlow
+
+  protected fun <T : I> Flow<T>.log(subject: String) = onEach { Log.d(tag, ">>> $subject: $it") }
+
+  companion object {
+    /**
+     * The buffer size that will be allocated by [kotlinx.coroutines.flow.MutableSharedFlow].
+     * If it falls behind by more than 64 state updates, it will start suspending.
+     * Slow consumers should consider using `stateFlow.buffer(onBufferOverflow = BufferOverflow.DROP_OLDEST)`.
+     *
+     * The internally allocated buffer is replay + extraBufferCapacity but always allocates 2^n space.
+     * We use replay=0 so buffer = 64.
+     */
+    const val SubscriberBufferSize = 64
+  }
 }

From b9485278762374aeebcc6494140d36621f1fd20d Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 20:35:16 +0700
Subject: [PATCH 02/21] refactor

---
 .../src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt     | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index 38dcb5bf..8c67d9b1 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -5,6 +5,7 @@ import androidx.lifecycle.ViewModel
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
@@ -36,7 +37,7 @@ abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEv
   override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
 
   protected suspend fun sendEvent(event: E) = eventChannel.send(event)
-  protected val intentFlow: Flow<I> get() = intentMutableFlow
+  protected val intentFlow: SharedFlow<I> get() = intentMutableFlow
 
   protected fun <T : I> Flow<T>.log(subject: String) = onEach { Log.d(tag, ">>> $subject: $it") }
 

From e62bc9c91d000558255d4257181889d762e0376e Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 20:35:43 +0700
Subject: [PATCH 03/21] refactor

---
 .../src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index 8c67d9b1..3e13b2eb 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -41,7 +41,7 @@ abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEv
 
   protected fun <T : I> Flow<T>.log(subject: String) = onEach { Log.d(tag, ">>> $subject: $it") }
 
-  companion object {
+  private companion object {
     /**
      * The buffer size that will be allocated by [kotlinx.coroutines.flow.MutableSharedFlow].
      * If it falls behind by more than 64 state updates, it will start suspending.
@@ -50,6 +50,6 @@ abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEv
      * The internally allocated buffer is replay + extraBufferCapacity but always allocates 2^n space.
      * We use replay=0 so buffer = 64.
      */
-    const val SubscriberBufferSize = 64
+    private const val SubscriberBufferSize = 64
   }
 }

From 831dd1d88f5e27185ac371ce611f2730363d3d49 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 20:47:35 +0700
Subject: [PATCH 04/21] lazy

---
 .../src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index 3e13b2eb..d5bcfc8b 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -28,7 +28,7 @@ interface MviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> {
 
 abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
   MviViewModel<I, S, E>, ViewModel() {
-  private val tag by lazy { this::class.java.simpleName.take(23) }
+  private val tag by lazy(LazyThreadSafetyMode.PUBLICATION) { this::class.java.simpleName.take(23) }
 
   private val eventChannel = Channel<E>(Channel.UNLIMITED)
   private val intentMutableFlow = MutableSharedFlow<I>(extraBufferCapacity = SubscriberBufferSize)

From e9d1f4c1c0cd2b5fa99493bb302226cbbb39af75 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 21:31:31 +0700
Subject: [PATCH 05/21] refactor AddVM

---
 .../com/hoc/flowmvi/ui/add/AddActivity.kt     |  14 +-
 .../com/hoc/flowmvi/ui/add/AddContract.kt     |  23 ++-
 .../main/java/com/hoc/flowmvi/ui/add/AddVM.kt | 179 ++++++++----------
 .../java/com/hoc/flowmvi/ui/main/MainVM.kt    |   3 +-
 .../com/hoc/flowmvi/mvi_base/MviViewModel.kt  |  19 +-
 5 files changed, 117 insertions(+), 121 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
index b33fc592..a86bd3c8 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
@@ -16,6 +16,7 @@ import com.hoc.flowmvi.core.firstChange
 import com.hoc.flowmvi.core.navigator.IntentProviders
 import com.hoc.flowmvi.core.textChanges
 import com.hoc.flowmvi.core.toast
+import com.hoc.flowmvi.mvi_base.MviView
 import com.hoc.flowmvi.ui.add.databinding.ActivityAddBinding
 import com.hoc081098.viewbindingdelegate.viewBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -27,7 +28,9 @@ import kotlinx.coroutines.flow.onEach
 import org.koin.androidx.viewmodel.ext.android.viewModel
 
 @ExperimentalCoroutinesApi
-class AddActivity : AppCompatActivity(R.layout.activity_add) {
+class AddActivity :
+  AppCompatActivity(R.layout.activity_add),
+  MviView<ViewIntent, ViewState, SingleEvent> {
   private val addVM by viewModel<AddVM>()
   private val addBinding by viewBinding<ActivityAddBinding>()
 
@@ -56,12 +59,12 @@ class AddActivity : AppCompatActivity(R.layout.activity_add) {
       .collectIn(this) { handleSingleEvent(it) }
 
     // pass view intent to view model
-    intents()
+    viewIntents()
       .onEach { addVM.processIntent(it) }
       .launchIn(lifecycleScope)
   }
 
-  private fun handleSingleEvent(event: SingleEvent) {
+  override fun handleSingleEvent(event: SingleEvent) {
     Log.d("###", "Event=$event")
 
     return when (event) {
@@ -76,7 +79,7 @@ class AddActivity : AppCompatActivity(R.layout.activity_add) {
     }
   }
 
-  private fun render(viewState: ViewState) {
+  override fun render(viewState: ViewState) {
     Log.d("###", "ViewState=$viewState")
 
     val emailErrorMessage = if (ValidationError.INVALID_EMAIL_ADDRESS in viewState.errors) {
@@ -127,8 +130,7 @@ class AddActivity : AppCompatActivity(R.layout.activity_add) {
     }
   }
 
-  @Suppress("NOTHING_TO_INLINE")
-  private inline fun intents(): Flow<ViewIntent> = addBinding.run {
+  override fun viewIntents(): Flow<ViewIntent> = addBinding.run {
     merge(
       emailEditText
         .editText!!
diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt
index 7448f25c..6fdb2788 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt
@@ -1,15 +1,22 @@
 package com.hoc.flowmvi.ui.add
 
+import arrow.core.ValidatedNel
+import arrow.core.invalidNel
 import com.hoc.flowmvi.domain.entity.User
 import com.hoc.flowmvi.domain.repository.UserError
+import com.hoc.flowmvi.mvi_base.MviIntent
+import com.hoc.flowmvi.mvi_base.MviSingleEvent
+import com.hoc.flowmvi.mvi_base.MviViewState
 
-internal enum class ValidationError {
+enum class ValidationError {
   INVALID_EMAIL_ADDRESS,
   TOO_SHORT_FIRST_NAME,
-  TOO_SHORT_LAST_NAME
+  TOO_SHORT_LAST_NAME;
+
+  val asInvalidNel: ValidatedNel<ValidationError, Nothing> = invalidNel()
 }
 
-internal data class ViewState(
+data class ViewState(
   val errors: Set<ValidationError>,
   val isLoading: Boolean,
   //
@@ -19,13 +26,13 @@ internal data class ViewState(
   //
   val email: String?,
   val firstName: String?,
-  val lastName: String?
-) {
+  val lastName: String?,
+) : MviViewState {
   companion object {
     fun initial(
       email: String?,
       firstName: String?,
-      lastName: String?
+      lastName: String?,
     ) = ViewState(
       errors = emptySet(),
 
@@ -40,7 +47,7 @@ internal data class ViewState(
   }
 }
 
-internal sealed interface ViewIntent {
+sealed interface ViewIntent : MviIntent {
   data class EmailChanged(val email: String?) : ViewIntent
   data class FirstNameChanged(val firstName: String?) : ViewIntent
   data class LastNameChanged(val lastName: String?) : ViewIntent
@@ -102,7 +109,7 @@ internal sealed interface PartialStateChange {
   }
 }
 
-internal sealed interface SingleEvent {
+sealed interface SingleEvent : MviSingleEvent {
   data class AddUserSuccess(val user: User) : SingleEvent
   data class AddUserFailure(val user: User, val error: UserError) : SingleEvent
 }
diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index 764ccbf6..5dc1f112 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -3,18 +3,18 @@ package com.hoc.flowmvi.ui.add
 import android.util.Log
 import androidx.core.util.PatternsCompat
 import androidx.lifecycle.SavedStateHandle
-import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
-import arrow.core.Either
-import arrow.core.identity
+import arrow.core.ValidatedNel
+import arrow.core.orNull
+import arrow.core.validNel
+import arrow.core.zip
 import com.hoc.flowmvi.domain.entity.User
 import com.hoc.flowmvi.domain.usecase.AddUserUseCase
+import com.hoc.flowmvi.mvi_base.BaseMviViewModel
 import com.hoc081098.flowext.flatMapFirst
 import com.hoc081098.flowext.withLatestFrom
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
@@ -27,23 +27,16 @@ import kotlinx.coroutines.flow.mapNotNull
 import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.onStart
-import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.scan
-import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.flow.stateIn
 
 @ExperimentalCoroutinesApi
 internal class AddVM(
   private val addUser: AddUserUseCase,
-  private val savedStateHandle: SavedStateHandle
-) : ViewModel() {
-  private val _eventChannel = Channel<SingleEvent>(Channel.BUFFERED)
-  private val _intentFlow = MutableSharedFlow<ViewIntent>(extraBufferCapacity = 64)
+  private val savedStateHandle: SavedStateHandle,
+) : BaseMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 
-  val viewState: StateFlow<ViewState>
-  val singleEvent: Flow<SingleEvent> get() = _eventChannel.receiveAsFlow()
-
-  fun processIntent(intent: ViewIntent) = _intentFlow.tryEmit(intent)
+  override val viewState: StateFlow<ViewState>
 
   init {
     val initialVS = ViewState.initial(
@@ -51,13 +44,13 @@ internal class AddVM(
       firstName = savedStateHandle.get<String?>(FIRST_NAME_KEY),
       lastName = savedStateHandle.get<String?>(LAST_NAME_KEY),
     )
-    Log.d("###", "[ADD_VM] initialVS: $initialVS")
+    Log.d(tag, "[ADD_VM] initialVS: $initialVS")
 
-    viewState = _intentFlow
+    viewState = intentFlow
       .toPartialStateChangesFlow()
       .sendSingleEvent()
       .scan(initialVS) { state, change -> change.reduce(state) }
-      .catch { Log.d("###", "[ADD_VM] Throwable: $it") }
+      .catch { Log.d(tag, "[ADD_VM] Throwable: $it") }
       .stateIn(viewModelScope, SharingStarted.Eagerly, initialVS)
   }
 
@@ -74,64 +67,62 @@ internal class AddVM(
         PartialStateChange.FirstChange.EmailChangedFirstTime -> return@onEach
         PartialStateChange.FirstChange.FirstNameChangedFirstTime -> return@onEach
         PartialStateChange.FirstChange.LastNameChangedFirstTime -> return@onEach
-        is PartialStateChange.FormValueChange.EmailChanged -> return@onEach
-        is PartialStateChange.FormValueChange.FirstNameChanged -> return@onEach
-        is PartialStateChange.FormValueChange.LastNameChanged -> return@onEach
+        is PartialStateChange.FormValueChange.EmailChanged -> {
+          savedStateHandle.set(EMAIL_KEY, change.email)
+          return@onEach
+        }
+        is PartialStateChange.FormValueChange.FirstNameChanged -> {
+          savedStateHandle.set(FIRST_NAME_KEY, change.firstName)
+          return@onEach
+        }
+        is PartialStateChange.FormValueChange.LastNameChanged -> {
+          savedStateHandle.set(LAST_NAME_KEY, change.lastName)
+          return@onEach
+        }
       }
-      _eventChannel.send(event)
+      sendEvent(event)
     }
   }
 
   private fun Flow<ViewIntent>.toPartialStateChangesFlow(): Flow<PartialStateChange> {
-    val emailErrors = filterIsInstance<ViewIntent.EmailChanged>()
+    val emailFlow = filterIsInstance<ViewIntent.EmailChanged>()
+      .log("Intent")
       .map { it.email }
       .distinctUntilChanged()
-      .map { validateEmail(it) to it }
-      .shareIn(
-        scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed()
-      )
+      .shareWhileSubscribed()
 
-    val firstNameErrors = filterIsInstance<ViewIntent.FirstNameChanged>()
+    val firstNameFlow = filterIsInstance<ViewIntent.FirstNameChanged>()
+      .log("Intent")
       .map { it.firstName }
       .distinctUntilChanged()
-      .map { validateFirstName(it) to it }
-      .shareIn(
-        scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed()
-      )
+      .shareWhileSubscribed()
 
-    val lastNameErrors = filterIsInstance<ViewIntent.LastNameChanged>()
+    val lastNameFlow = filterIsInstance<ViewIntent.LastNameChanged>()
+      .log("Intent")
       .map { it.lastName }
       .distinctUntilChanged()
-      .map { validateLastName(it) to it }
-      .shareIn(
-        scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed()
-      )
-
-    val userFormFlow =
-      combine(emailErrors, firstNameErrors, lastNameErrors) { email, firstName, lastName ->
-        val errors = email.first + firstName.first + lastName.first
-
-        if (errors.isEmpty()) Either.Right(
-          User(
-            firstName = firstName.second!!,
-            email = email.second!!,
-            lastName = lastName.second!!,
-            id = "",
-            avatar = ""
-          )
-        ) else Either.Left(errors)
-      }
-        .shareIn(
-          scope = viewModelScope,
-          started = SharingStarted.WhileSubscribed()
+      .shareWhileSubscribed()
+
+    val userFormFlow = combine(
+      emailFlow.map { validateEmail(it) }.distinctUntilChanged(),
+      firstNameFlow.map { validateFirstName(it) }.distinctUntilChanged(),
+      lastNameFlow.map { validateLastName(it) }.distinctUntilChanged(),
+    ) { emailValidated, firstNameValidated, lastNameValidated ->
+      emailValidated.zip(firstNameValidated, lastNameValidated) { email, firstName, lastName ->
+        User(
+          firstName = firstName,
+          email = email,
+          lastName = lastName,
+          id = "",
+          avatar = ""
         )
+      }
+    }.stateWithInitialNullWhileSubscribed()
 
     val addUserChanges = filterIsInstance<ViewIntent.Submit>()
+      .log("Intent")
       .withLatestFrom(userFormFlow) { _, userForm -> userForm }
-      .mapNotNull { it.orNull() }
+      .mapNotNull { it?.orNull() }
       .flatMapFirst { user ->
         flow { emit(addUser(user)) }
           .map { result ->
@@ -145,35 +136,33 @@ internal class AddVM(
 
     val firstChanges = merge(
       filterIsInstance<ViewIntent.EmailChangedFirstTime>()
+        .log("Intent")
         .map { PartialStateChange.FirstChange.EmailChangedFirstTime },
       filterIsInstance<ViewIntent.FirstNameChangedFirstTime>()
+        .log("Intent")
         .map { PartialStateChange.FirstChange.FirstNameChangedFirstTime },
       filterIsInstance<ViewIntent.LastNameChangedFirstTime>()
+        .log("Intent")
         .map { PartialStateChange.FirstChange.LastNameChangedFirstTime }
     )
 
     val formValuesChanges = merge(
-      emailErrors
-        .map { it.second }
-        .onEach { savedStateHandle.set(EMAIL_KEY, it) }
-        .map { PartialStateChange.FormValueChange.EmailChanged(it) },
-      firstNameErrors
-        .map { it.second }
-        .onEach { savedStateHandle.set(FIRST_NAME_KEY, it) }
-        .map { PartialStateChange.FormValueChange.FirstNameChanged(it) },
-      lastNameErrors
-        .map { it.second }
-        .onEach { savedStateHandle.set(LAST_NAME_KEY, it) }
-        .map { PartialStateChange.FormValueChange.LastNameChanged(it) },
+      emailFlow.map { PartialStateChange.FormValueChange.EmailChanged(it) },
+      firstNameFlow.map { PartialStateChange.FormValueChange.FirstNameChanged(it) },
+      lastNameFlow.map { PartialStateChange.FormValueChange.LastNameChanged(it) },
     )
 
+    val errorsChanges = userFormFlow.map { validated ->
+      PartialStateChange.ErrorsChanged(
+        validated?.fold(
+          { it.toSet() },
+          { emptySet() }
+        ) ?: emptySet()
+      )
+    }
+
     return merge(
-      userFormFlow
-        .map {
-          PartialStateChange.ErrorsChanged(
-            it.fold(::identity) { emptySet() }
-          )
-        },
+      errorsChanges,
       addUserChanges,
       firstChanges,
       formValuesChanges,
@@ -188,40 +177,28 @@ internal class AddVM(
     const val MIN_LENGTH_FIRST_NAME = 3
     const val MIN_LENGTH_LAST_NAME = 3
 
-    fun validateFirstName(firstName: String?): Set<ValidationError> {
-      val errors = mutableSetOf<ValidationError>()
-
+    fun validateFirstName(firstName: String?): ValidatedNel<ValidationError, String> {
       if (firstName == null || firstName.length < MIN_LENGTH_FIRST_NAME) {
-        errors += ValidationError.TOO_SHORT_FIRST_NAME
+        return ValidationError.TOO_SHORT_FIRST_NAME.asInvalidNel
       }
-
-      // more validation here
-
-      return errors
+      // more validations here
+      return firstName.validNel()
     }
 
-    fun validateLastName(lastName: String?): Set<ValidationError> {
-      val errors = mutableSetOf<ValidationError>()
-
+    fun validateLastName(lastName: String?): ValidatedNel<ValidationError, String> {
       if (lastName == null || lastName.length < MIN_LENGTH_LAST_NAME) {
-        errors += ValidationError.TOO_SHORT_LAST_NAME
+        return ValidationError.TOO_SHORT_LAST_NAME.asInvalidNel
       }
-
-      // more validation here
-
-      return errors
+      // more validations here
+      return lastName.validNel()
     }
 
-    fun validateEmail(email: String?): Set<ValidationError> {
-      val errors = mutableSetOf<ValidationError>()
-
+    fun validateEmail(email: String?): ValidatedNel<ValidationError, String> {
       if (email == null || !PatternsCompat.EMAIL_ADDRESS.matcher(email).matches()) {
-        errors += ValidationError.INVALID_EMAIL_ADDRESS
+        return ValidationError.INVALID_EMAIL_ADDRESS.asInvalidNel
       }
-
-      // more validation here
-
-      return errors
+      // more validations here
+      return email.validNel()
     }
   }
 }
diff --git a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
index 5c291d67..04042be3 100644
--- a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
+++ b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
@@ -26,7 +26,6 @@ import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.flow.scan
-import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.take
 
@@ -78,7 +77,7 @@ class MainVM(
   }
 
   private fun Flow<ViewIntent>.toPartialChangeFlow(): Flow<PartialChange> =
-    shareIn(viewModelScope, SharingStarted.WhileSubscribed()).run {
+    shareWhileSubscribed().run {
       val getUserChanges = defer(getUsersUseCase::invoke)
         .onEach { either -> Log.d("###", "[MAIN_VM] Emit users.size=${either.map { it.size }}") }
         .map { result ->
diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index d5bcfc8b..31482058 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -2,13 +2,17 @@ package com.hoc.flowmvi.mvi_base
 
 import android.util.Log
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.shareIn
+import kotlinx.coroutines.flow.stateIn
 
 /**
  * Object that will subscribes to a MviView's [MviIntent]s,
@@ -28,18 +32,25 @@ interface MviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> {
 
 abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
   MviViewModel<I, S, E>, ViewModel() {
-  private val tag by lazy(LazyThreadSafetyMode.PUBLICATION) { this::class.java.simpleName.take(23) }
+  protected val tag by lazy(LazyThreadSafetyMode.PUBLICATION) { this::class.java.simpleName.take(23) }
 
   private val eventChannel = Channel<E>(Channel.UNLIMITED)
   private val intentMutableFlow = MutableSharedFlow<I>(extraBufferCapacity = SubscriberBufferSize)
 
-  override val singleEvent: Flow<E> get() = eventChannel.receiveAsFlow()
-  override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
+  final override val singleEvent: Flow<E> get() = eventChannel.receiveAsFlow()
+  final override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
 
   protected suspend fun sendEvent(event: E) = eventChannel.send(event)
   protected val intentFlow: SharedFlow<I> get() = intentMutableFlow
 
-  protected fun <T : I> Flow<T>.log(subject: String) = onEach { Log.d(tag, ">>> $subject: $it") }
+  protected fun <T> Flow<T>.log(subject: String): Flow<T> =
+    onEach { Log.d(tag, ">>> $subject: $it") }
+
+  protected fun <T> Flow<T>.shareWhileSubscribed(): SharedFlow<T> =
+    shareIn(viewModelScope, SharingStarted.WhileSubscribed())
+
+  protected fun <T> Flow<T>.stateWithInitialNullWhileSubscribed(): StateFlow<T?> =
+    stateIn(viewModelScope, SharingStarted.WhileSubscribed(), null)
 
   private companion object {
     /**

From 3bc6f23383abf6525a8e1c2273b025f97694ab55 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 21:33:20 +0700
Subject: [PATCH 06/21] refactor AddVM

---
 .../src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt      |  4 ++--
 .../main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt | 10 ++++++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index 5dc1f112..6e617fcb 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -44,13 +44,13 @@ internal class AddVM(
       firstName = savedStateHandle.get<String?>(FIRST_NAME_KEY),
       lastName = savedStateHandle.get<String?>(LAST_NAME_KEY),
     )
-    Log.d(tag, "[ADD_VM] initialVS: $initialVS")
+    Log.d(logTag, "[ADD_VM] initialVS: $initialVS")
 
     viewState = intentFlow
       .toPartialStateChangesFlow()
       .sendSingleEvent()
       .scan(initialVS) { state, change -> change.reduce(state) }
-      .catch { Log.d(tag, "[ADD_VM] Throwable: $it") }
+      .catch { Log.d(logTag, "[ADD_VM] Throwable: $it") }
       .stateIn(viewModelScope, SharingStarted.Eagerly, initialVS)
   }
 
diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index 31482058..8cfe0719 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -32,7 +32,9 @@ interface MviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> {
 
 abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
   MviViewModel<I, S, E>, ViewModel() {
-  protected val tag by lazy(LazyThreadSafetyMode.PUBLICATION) { this::class.java.simpleName.take(23) }
+  protected val logTag by lazy(LazyThreadSafetyMode.PUBLICATION) {
+    this::class.java.simpleName.take(23)
+  }
 
   private val eventChannel = Channel<E>(Channel.UNLIMITED)
   private val intentMutableFlow = MutableSharedFlow<I>(extraBufferCapacity = SubscriberBufferSize)
@@ -40,11 +42,15 @@ abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEv
   final override val singleEvent: Flow<E> get() = eventChannel.receiveAsFlow()
   final override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
 
+  // Send event and access intent flow.
+
   protected suspend fun sendEvent(event: E) = eventChannel.send(event)
   protected val intentFlow: SharedFlow<I> get() = intentMutableFlow
 
+  // Extensions on Flow using viewModelScope.
+
   protected fun <T> Flow<T>.log(subject: String): Flow<T> =
-    onEach { Log.d(tag, ">>> $subject: $it") }
+    onEach { Log.d(logTag, ">>> $subject: $it") }
 
   protected fun <T> Flow<T>.shareWhileSubscribed(): SharedFlow<T> =
     shareIn(viewModelScope, SharingStarted.WhileSubscribed())

From 7e5ae5f083cb94dd8556d8f132c69942ca7ed1eb Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 21:34:01 +0700
Subject: [PATCH 07/21] split file

---
 .../hoc/flowmvi/mvi_base/BaseMviViewModel.kt  | 56 +++++++++++++++++++
 .../com/hoc/flowmvi/mvi_base/MviViewModel.kt  | 52 -----------------
 2 files changed, 56 insertions(+), 52 deletions(-)
 create mode 100644 mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt

diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt
new file mode 100644
index 00000000..4b22f492
--- /dev/null
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt
@@ -0,0 +1,56 @@
+package com.hoc.flowmvi.mvi_base
+
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.shareIn
+import kotlinx.coroutines.flow.stateIn
+
+abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
+  MviViewModel<I, S, E>, ViewModel() {
+  protected val logTag by lazy(LazyThreadSafetyMode.PUBLICATION) {
+    this::class.java.simpleName.take(23)
+  }
+
+  private val eventChannel = Channel<E>(Channel.UNLIMITED)
+  private val intentMutableFlow = MutableSharedFlow<I>(extraBufferCapacity = SubscriberBufferSize)
+
+  final override val singleEvent: Flow<E> get() = eventChannel.receiveAsFlow()
+  final override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
+
+  // Send event and access intent flow.
+
+  protected suspend fun sendEvent(event: E) = eventChannel.send(event)
+  protected val intentFlow: SharedFlow<I> get() = intentMutableFlow
+
+  // Extensions on Flow using viewModelScope.
+
+  protected fun <T> Flow<T>.log(subject: String): Flow<T> =
+    onEach { Log.d(logTag, ">>> $subject: $it") }
+
+  protected fun <T> Flow<T>.shareWhileSubscribed(): SharedFlow<T> =
+    shareIn(viewModelScope, SharingStarted.WhileSubscribed())
+
+  protected fun <T> Flow<T>.stateWithInitialNullWhileSubscribed(): StateFlow<T?> =
+    stateIn(viewModelScope, SharingStarted.WhileSubscribed(), null)
+
+  private companion object {
+    /**
+     * The buffer size that will be allocated by [kotlinx.coroutines.flow.MutableSharedFlow].
+     * If it falls behind by more than 64 state updates, it will start suspending.
+     * Slow consumers should consider using `stateFlow.buffer(onBufferOverflow = BufferOverflow.DROP_OLDEST)`.
+     *
+     * The internally allocated buffer is replay + extraBufferCapacity but always allocates 2^n space.
+     * We use replay=0 so buffer = 64.
+     */
+    private const val SubscriberBufferSize = 64
+  }
+}
diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
index 8cfe0719..daa52d4d 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/MviViewModel.kt
@@ -1,18 +1,7 @@
 package com.hoc.flowmvi.mvi_base
 
-import android.util.Log
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
-import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableSharedFlow
-import kotlinx.coroutines.flow.SharedFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.flow.receiveAsFlow
-import kotlinx.coroutines.flow.shareIn
-import kotlinx.coroutines.flow.stateIn
 
 /**
  * Object that will subscribes to a MviView's [MviIntent]s,
@@ -29,44 +18,3 @@ interface MviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> {
 
   suspend fun processIntent(intent: I)
 }
-
-abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
-  MviViewModel<I, S, E>, ViewModel() {
-  protected val logTag by lazy(LazyThreadSafetyMode.PUBLICATION) {
-    this::class.java.simpleName.take(23)
-  }
-
-  private val eventChannel = Channel<E>(Channel.UNLIMITED)
-  private val intentMutableFlow = MutableSharedFlow<I>(extraBufferCapacity = SubscriberBufferSize)
-
-  final override val singleEvent: Flow<E> get() = eventChannel.receiveAsFlow()
-  final override suspend fun processIntent(intent: I) = intentMutableFlow.emit(intent)
-
-  // Send event and access intent flow.
-
-  protected suspend fun sendEvent(event: E) = eventChannel.send(event)
-  protected val intentFlow: SharedFlow<I> get() = intentMutableFlow
-
-  // Extensions on Flow using viewModelScope.
-
-  protected fun <T> Flow<T>.log(subject: String): Flow<T> =
-    onEach { Log.d(logTag, ">>> $subject: $it") }
-
-  protected fun <T> Flow<T>.shareWhileSubscribed(): SharedFlow<T> =
-    shareIn(viewModelScope, SharingStarted.WhileSubscribed())
-
-  protected fun <T> Flow<T>.stateWithInitialNullWhileSubscribed(): StateFlow<T?> =
-    stateIn(viewModelScope, SharingStarted.WhileSubscribed(), null)
-
-  private companion object {
-    /**
-     * The buffer size that will be allocated by [kotlinx.coroutines.flow.MutableSharedFlow].
-     * If it falls behind by more than 64 state updates, it will start suspending.
-     * Slow consumers should consider using `stateFlow.buffer(onBufferOverflow = BufferOverflow.DROP_OLDEST)`.
-     *
-     * The internally allocated buffer is replay + extraBufferCapacity but always allocates 2^n space.
-     * We use replay=0 so buffer = 64.
-     */
-    private const val SubscriberBufferSize = 64
-  }
-}

From 85b048a745bd178170c4fdd8dd7ac9707ee9bd4b Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 21:37:03 +0700
Subject: [PATCH 08/21] update README [skip ci]

---
 README.md | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index ddc1a5db..686c09de 100644
--- a/README.md
+++ b/README.md
@@ -10,10 +10,10 @@
 
 ## Coroutine + Flow = MVI :heart:
 *   Play MVI with Kotlin Coroutines Flow.
-*   Multiple modules, Clean Architecture.
+*   Multiple modules, Clean Architecture, Functional programming with [ΛRROW.kt](https://arrow-kt.io/).
 *   Unit tests for MVI ViewModel, domain and data layer.
 *   Master branch using Koin for DI.
-*   **Checkout [dagger_hilt branch](https://github.com/Kotlin-Android-Open-Source/MVI-Coroutines-Flow/tree/dagger_hilt), using Dagger Hilt for DI** (_obsolete_).
+*   **Checkout [dagger_hilt branch](https://github.com/Kotlin-Android-Open-Source/MVI-Coroutines-Flow/tree/dagger_hilt), using Dagger Hilt for DI** (_obsolete, will update as soon as possible_).
 *   **[Download latest debug APK here](https://nightly.link/Kotlin-Android-Open-Source/MVI-Coroutines-Flow/workflows/build/master/app-debug.zip)**.
 
 > **Jetpack Compose Version** 👉 https://github.com/Kotlin-Android-Open-Source/Jetpack-Compose-MVI-Coroutines-Flow
@@ -35,7 +35,7 @@ This pattern was specified by [André Medeiros (Staltz)](https://twitter.com/and
 <p align="center">
   <img src="MVI_diagram.png">
 <p>
-  
+
 - `intent()`: This function takes the input from the user (i.e. UI events, like click events) and translate it to “something” that will be passed as parameter to `model()` function.
   This could be a simple string to set a value of the model to or more complex data structure like an Object. We could say we have the intention to change the model with an intent.
 - `model()`: The `model()` function takes the output from `intent()` as input to manipulate the Model. The output of this function is a new Model (state changed).
@@ -48,10 +48,10 @@ This pattern was specified by [André Medeiros (Staltz)](https://twitter.com/and
 - `view()`: This method takes the model returned from `model()` function and gives it as input to the `view()` function. Then the View simply displays this Model somehow. `view()` is basically the same as `view.render(model)`.
 
 ### Reference
-  
+
 - [Model-View-Intent Design Pattern on Android](https://xizzhu.me/post/2021-06-21-android-mvi-kotlin-coroutines-flow-compose/)
 - [Reactive Apps with Model-View-Intent](https://hannesdorfmann.com/android/mosby3-mvi-1/)
-  
+
 ## Contributors ✨
 
 Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/docs/en/emoji-key)):

From bb10d027578b86262e1f3a3441dd9ddaac4b9d3e Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 21:38:23 +0700
Subject: [PATCH 09/21] rename [skip ci]

---
 feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt     | 4 ++--
 feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt  | 4 ++--
 .../mvi_base/{BaseMviViewModel.kt => AbstractMviViewModel.kt} | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)
 rename mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/{BaseMviViewModel.kt => AbstractMviViewModel.kt} (96%)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index 6e617fcb..6085b421 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -10,7 +10,7 @@ import arrow.core.validNel
 import arrow.core.zip
 import com.hoc.flowmvi.domain.entity.User
 import com.hoc.flowmvi.domain.usecase.AddUserUseCase
-import com.hoc.flowmvi.mvi_base.BaseMviViewModel
+import com.hoc.flowmvi.mvi_base.AbstractMviViewModel
 import com.hoc081098.flowext.flatMapFirst
 import com.hoc081098.flowext.withLatestFrom
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -34,7 +34,7 @@ import kotlinx.coroutines.flow.stateIn
 internal class AddVM(
   private val addUser: AddUserUseCase,
   private val savedStateHandle: SavedStateHandle,
-) : BaseMviViewModel<ViewIntent, ViewState, SingleEvent>() {
+) : AbstractMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 
   override val viewState: StateFlow<ViewState>
 
diff --git a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
index 04042be3..e119906c 100644
--- a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
+++ b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainVM.kt
@@ -5,7 +5,7 @@ import androidx.lifecycle.viewModelScope
 import com.hoc.flowmvi.domain.usecase.GetUsersUseCase
 import com.hoc.flowmvi.domain.usecase.RefreshGetUsersUseCase
 import com.hoc.flowmvi.domain.usecase.RemoveUserUseCase
-import com.hoc.flowmvi.mvi_base.BaseMviViewModel
+import com.hoc.flowmvi.mvi_base.AbstractMviViewModel
 import com.hoc081098.flowext.flatMapFirst
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.FlowPreview
@@ -35,7 +35,7 @@ class MainVM(
   private val getUsersUseCase: GetUsersUseCase,
   private val refreshGetUsers: RefreshGetUsersUseCase,
   private val removeUser: RemoveUserUseCase,
-) : BaseMviViewModel<ViewIntent, ViewState, SingleEvent>() {
+) : AbstractMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 
   override val viewState: StateFlow<ViewState>
 
diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviViewModel.kt
similarity index 96%
rename from mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt
rename to mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviViewModel.kt
index 4b22f492..c47af2bd 100644
--- a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/BaseMviViewModel.kt
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviViewModel.kt
@@ -14,7 +14,7 @@ import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.flow.stateIn
 
-abstract class BaseMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
+abstract class AbstractMviViewModel<I : MviIntent, S : MviViewState, E : MviSingleEvent> :
   MviViewModel<I, S, E>, ViewModel() {
   protected val logTag by lazy(LazyThreadSafetyMode.PUBLICATION) {
     this::class.java.simpleName.take(23)

From 22f9c56d98c0c78e77491ed59071694af293deef Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 22:19:23 +0700
Subject: [PATCH 10/21] SearchVM.kt

---
 .../hoc/flowmvi/ui/search/SearchActivity.kt   | 68 +++++++++++--------
 .../hoc/flowmvi/ui/search/SearchContract.kt   | 13 ++--
 .../com/hoc/flowmvi/ui/search/SearchVM.kt     | 25 ++-----
 3 files changed, 53 insertions(+), 53 deletions(-)

diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index e66ee252..efd29c15 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -20,6 +20,7 @@ import com.hoc.flowmvi.core.navigator.IntentProviders
 import com.hoc.flowmvi.core.queryTextEvents
 import com.hoc.flowmvi.core.toast
 import com.hoc.flowmvi.domain.repository.UserError
+import com.hoc.flowmvi.mvi_base.MviView
 import com.hoc.flowmvi.ui.search.databinding.ActivitySearchBinding
 import com.hoc081098.viewbindingdelegate.viewBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -37,7 +38,9 @@ import kotlin.time.ExperimentalTime
 @ExperimentalCoroutinesApi
 @FlowPreview
 @ExperimentalTime
-class SearchActivity : AppCompatActivity(R.layout.activity_search) {
+class SearchActivity :
+  AppCompatActivity(R.layout.activity_search),
+  MviView<ViewIntent, ViewState, SingleEvent> {
   private val binding by viewBinding<ActivitySearchBinding>()
   private val vm by viewModel<SearchVM>()
 
@@ -53,42 +56,47 @@ class SearchActivity : AppCompatActivity(R.layout.activity_search) {
   }
 
   private fun bindVM() {
-    vm.viewState.collectIn(this) { viewState ->
-      searchAdapter.submitList(viewState.users)
-
-      binding.run {
-        textQuery.isInvisible = viewState.isLoading || viewState.query.isBlank()
-        textQuery.text = "Search results for '${viewState.query}'"
-
-        errorGroup.isVisible = viewState.error !== null
-        errorMessageTextView.text = viewState.error?.let {
-          when (it) {
-            is UserError.InvalidId -> "Invalid id"
-            UserError.NetworkError -> "Network error"
-            UserError.ServerError -> "Server error"
-            UserError.Unexpected -> "Unexpected error"
-            is UserError.UserNotFound -> "User not found"
-            UserError.ValidationFailed -> "Validation failed"
-          }
-        }
+    vm.viewState
+      .collectIn(this) { viewState -> render(viewState) }
 
-        progressBar.isVisible = viewState.isLoading
-      }
+    vm.singleEvent
+      .collectIn(this) { event -> handleSingleEvent(event) }
+
+    viewIntents()
+      .onEach { vm.processIntent(it) }
+      .launchIn(lifecycleScope)
+  }
+
+  override fun handleSingleEvent(event: SingleEvent) {
+    when (event) {
+      is SingleEvent.SearchFailure -> toast("Failed to search")
     }
+  }
 
-    vm.singleEvent.collectIn(this) { event ->
-      when (event) {
-        is SingleEvent.SearchFailure -> toast("Failed to search")
+  override fun render(viewState: ViewState) {
+    searchAdapter.submitList(viewState.users)
+
+    binding.run {
+      textQuery.isInvisible = viewState.isLoading || viewState.query.isBlank()
+      textQuery.text = "Search results for '${viewState.query}'"
+
+      errorGroup.isVisible = viewState.error !== null
+      errorMessageTextView.text = viewState.error?.let {
+        when (it) {
+          is UserError.InvalidId -> "Invalid id"
+          UserError.NetworkError -> "Network error"
+          UserError.ServerError -> "Server error"
+          UserError.Unexpected -> "Unexpected error"
+          is UserError.UserNotFound -> "User not found"
+          UserError.ValidationFailed -> "Validation failed"
+        }
       }
-    }
 
-    intents()
-      .onEach { vm.processIntent(it) }
-      .launchIn(lifecycleScope)
+      progressBar.isVisible = viewState.isLoading
+    }
   }
 
-  @Suppress("NOTHING_TO_INLINE")
-  private inline fun intents(): Flow<ViewIntent> = merge(
+  override fun viewIntents(): Flow<ViewIntent> = merge(
     searchViewQueryTextEventChannel
       .consumeAsFlow()
       .onEach { Log.d("SearchActivity", "Query $it") }
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
index bcd4f5cb..7bca2eac 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
@@ -2,11 +2,14 @@ package com.hoc.flowmvi.ui.search
 
 import com.hoc.flowmvi.domain.entity.User
 import com.hoc.flowmvi.domain.repository.UserError
+import com.hoc.flowmvi.mvi_base.MviIntent
+import com.hoc.flowmvi.mvi_base.MviSingleEvent
+import com.hoc.flowmvi.mvi_base.MviViewState
 import dev.ahmedmourad.nocopy.annotations.NoCopy
 
 @Suppress("DataClassPrivateConstructor")
 @NoCopy
-internal data class UserItem private constructor(
+data class UserItem private constructor(
   val id: String,
   val email: String,
   val avatar: String,
@@ -24,17 +27,17 @@ internal data class UserItem private constructor(
   }
 }
 
-internal sealed interface ViewIntent {
+sealed interface ViewIntent : MviIntent {
   data class Search(val query: String) : ViewIntent
   object Retry : ViewIntent
 }
 
-internal data class ViewState(
+data class ViewState(
   val users: List<UserItem>,
   val isLoading: Boolean,
   val error: UserError?,
   val query: String,
-) {
+) : MviViewState {
   companion object Factory {
     fun initial(): ViewState {
       return ViewState(
@@ -69,6 +72,6 @@ internal sealed interface PartialStateChange {
   }
 }
 
-internal sealed interface SingleEvent {
+sealed interface SingleEvent : MviSingleEvent {
   data class SearchFailure(val error: UserError) : SingleEvent
 }
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
index 88958e70..92ecc1c4 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
@@ -1,16 +1,14 @@
 package com.hoc.flowmvi.ui.search
 
 import android.util.Log
-import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.hoc.flowmvi.domain.usecase.SearchUsersUseCase
+import com.hoc.flowmvi.mvi_base.AbstractMviViewModel
 import com.hoc081098.flowext.flatMapFirst
 import com.hoc081098.flowext.takeUntil
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.FlowPreview
-import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
@@ -25,9 +23,7 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.onStart
-import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.scan
-import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.flow.stateIn
 import kotlin.time.Duration
 import kotlin.time.ExperimentalTime
@@ -37,22 +33,18 @@ import kotlin.time.ExperimentalTime
 @ExperimentalCoroutinesApi
 internal class SearchVM(
   private val searchUsersUseCase: SearchUsersUseCase,
-) : ViewModel() {
-  private val _intentFlow = MutableSharedFlow<ViewIntent>(extraBufferCapacity = 64)
-  private val _singleEvent = Channel<SingleEvent>(Channel.BUFFERED)
+) : AbstractMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 
-  val viewState: StateFlow<ViewState>
-  val singleEvent: Flow<SingleEvent> get() = _singleEvent.receiveAsFlow()
-  fun processIntent(intent: ViewIntent) = _intentFlow.tryEmit(intent)
+  override val viewState: StateFlow<ViewState>
 
   init {
     val initialVS = ViewState.initial()
 
-    viewState = _intentFlow
+    viewState = intentFlow
       .toPartialStateChangesFlow()
       .sendSingleEvent()
       .scan(initialVS) { state, change -> change.reduce(state) }
-      .catch { Log.d("###", "[SEARCH_VM] Throwable: $it") }
+      .catch { Log.d(logTag, "[SEARCH_VM] Throwable: $it") }
       .stateIn(viewModelScope, SharingStarted.Eagerly, initialVS)
   }
 
@@ -78,10 +70,7 @@ internal class SearchVM(
       .map { it.query }
       .filter { it.isNotBlank() }
       .distinctUntilChanged()
-      .shareIn(
-        scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed(),
-      )
+      .shareWhileSubscribed()
 
     return merge(
       queryFlow.flatMapLatest(executeSearch),
@@ -98,7 +87,7 @@ internal class SearchVM(
   private fun Flow<PartialStateChange>.sendSingleEvent(): Flow<PartialStateChange> =
     onEach { change ->
       when (change) {
-        is PartialStateChange.Failure -> _singleEvent.send(SingleEvent.SearchFailure(change.error))
+        is PartialStateChange.Failure -> sendEvent(SingleEvent.SearchFailure(change.error))
         PartialStateChange.Loading -> return@onEach
         is PartialStateChange.Success -> return@onEach
       }

From ad5426a52a0137ce60ca61b3d43db4fc89f87ef6 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 22:48:30 +0700
Subject: [PATCH 11/21] AbstractMviActivity

---
 .../com/hoc/flowmvi/ui/main/MainActivity.kt   | 39 ++-------------
 mvi/mvi-base/build.gradle.kts                 |  4 ++
 .../flowmvi/mvi_base/AbstractMviActivity.kt   | 47 +++++++++++++++++++
 3 files changed, 56 insertions(+), 34 deletions(-)
 create mode 100644 mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviActivity.kt

diff --git a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt
index e1a790fa..2b75a8a8 100644
--- a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt
+++ b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt
@@ -1,24 +1,20 @@
 package com.hoc.flowmvi.ui.main
 
-import android.os.Bundle
 import android.util.Log
 import android.view.Menu
 import android.view.MenuItem
-import androidx.appcompat.app.AppCompatActivity
 import androidx.core.view.isVisible
-import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.ItemTouchHelper
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import com.hoc.flowmvi.core.SwipeLeftToDeleteCallback
 import com.hoc.flowmvi.core.clicks
-import com.hoc.flowmvi.core.collectIn
 import com.hoc.flowmvi.core.navigator.Navigator
 import com.hoc.flowmvi.core.refreshes
 import com.hoc.flowmvi.core.toast
 import com.hoc.flowmvi.domain.repository.UserError
-import com.hoc.flowmvi.mvi_base.MviView
+import com.hoc.flowmvi.mvi_base.AbstractMviActivity
 import com.hoc.flowmvi.ui.main.databinding.ActivityMainBinding
 import com.hoc081098.viewbindingdelegate.viewBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -27,19 +23,16 @@ import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.consumeAsFlow
 import kotlinx.coroutines.flow.flowOf
-import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.merge
-import kotlinx.coroutines.flow.onEach
 import org.koin.android.ext.android.inject
 import org.koin.androidx.viewmodel.ext.android.viewModel
 
 @FlowPreview
 @ExperimentalCoroutinesApi
 class MainActivity :
-  AppCompatActivity(R.layout.activity_main),
-  MviView<ViewIntent, ViewState, SingleEvent> {
-  private val mainVM by viewModel<MainVM>()
+  AbstractMviActivity<ViewIntent, ViewState, SingleEvent, MainVM>(R.layout.activity_main) {
+  override val vm by viewModel<MainVM>()
   private val navigator by inject<Navigator>()
 
   private val userAdapter = UserAdapter()
@@ -47,13 +40,6 @@ class MainActivity :
 
   private val removeChannel = Channel<UserItem>(Channel.BUFFERED)
 
-  override fun onCreate(savedInstanceState: Bundle?) {
-    super.onCreate(savedInstanceState)
-
-    setupViews()
-    bindVM(mainVM)
-  }
-
   override fun onOptionsItemSelected(item: MenuItem): Boolean {
     return when (item.itemId) {
       R.id.add_action -> {
@@ -71,7 +57,7 @@ class MainActivity :
   override fun onCreateOptionsMenu(menu: Menu?) =
     menuInflater.inflate(R.menu.menu_main, menu).let { true }
 
-  private fun setupViews() {
+  override fun setupViews() {
     mainBinding.usersRecycler.run {
       setHasFixedSize(true)
       layoutManager = LinearLayoutManager(context, RecyclerView.VERTICAL, false)
@@ -80,28 +66,13 @@ class MainActivity :
 
       ItemTouchHelper(
         SwipeLeftToDeleteCallback(context) cb@{ position ->
-          val userItem = mainVM.viewState.value.userItems[position]
+          val userItem = vm.viewState.value.userItems[position]
           removeChannel.trySend(userItem)
         }
       ).attachToRecyclerView(this)
     }
   }
 
-  private fun bindVM(mainVM: MainVM) {
-    // observe view model
-    mainVM.viewState
-      .collectIn(this) { render(it) }
-
-    // observe single event
-    mainVM.singleEvent
-      .collectIn(this) { handleSingleEvent(it) }
-
-    // pass view intent to view model
-    viewIntents()
-      .onEach { mainVM.processIntent(it) }
-      .launchIn(lifecycleScope)
-  }
-
   override fun viewIntents(): Flow<ViewIntent> = merge(
     flowOf(ViewIntent.Initial),
     mainBinding.swipeRefreshLayout.refreshes().map { ViewIntent.Refresh },
diff --git a/mvi/mvi-base/build.gradle.kts b/mvi/mvi-base/build.gradle.kts
index eaa84e13..fe6f9c55 100644
--- a/mvi/mvi-base/build.gradle.kts
+++ b/mvi/mvi-base/build.gradle.kts
@@ -32,8 +32,12 @@ android {
 }
 
 dependencies {
+  implementation(deps.androidx.appCompat)
   implementation(deps.lifecycle.viewModelKtx)
+  implementation(deps.lifecycle.runtimeKtx)
   implementation(deps.coroutines.core)
 
+  implementation(core)
+
   addUnitTest()
 }
diff --git a/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviActivity.kt b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviActivity.kt
new file mode 100644
index 00000000..cbb29495
--- /dev/null
+++ b/mvi/mvi-base/src/main/java/com/hoc/flowmvi/mvi_base/AbstractMviActivity.kt
@@ -0,0 +1,47 @@
+package com.hoc.flowmvi.mvi_base
+
+import android.os.Bundle
+import androidx.annotation.CallSuper
+import androidx.annotation.LayoutRes
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.lifecycleScope
+import com.hoc.flowmvi.core.collectIn
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+
+abstract class AbstractMviActivity<
+  I : MviIntent,
+  S : MviViewState,
+  E : MviSingleEvent,
+  VM : MviViewModel<I, S, E>,
+  >(
+  @LayoutRes contentLayoutId: Int,
+) :
+  AppCompatActivity(contentLayoutId), MviView<I, S, E> {
+  protected abstract val vm: VM
+
+  @CallSuper
+  override fun onCreate(savedInstanceState: Bundle?) {
+    super.onCreate(savedInstanceState)
+
+    setupViews()
+    bindVM()
+  }
+
+  private fun bindVM() {
+    // observe view model
+    vm.viewState
+      .collectIn(this) { render(it) }
+
+    // observe single event
+    vm.singleEvent
+      .collectIn(this) { handleSingleEvent(it) }
+
+    // pass view intent to view model
+    viewIntents()
+      .onEach { vm.processIntent(it) }
+      .launchIn(lifecycleScope)
+  }
+
+  protected abstract fun setupViews()
+}

From 23066ffc9990136fd2d918a2ccdf07bbc5629802 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 22:53:22 +0700
Subject: [PATCH 12/21] AbstractMviActivity

---
 .../com/hoc/flowmvi/ui/add/AddActivity.kt     | 42 ++++---------------
 .../main/java/com/hoc/flowmvi/ui/add/AddVM.kt |  2 +-
 2 files changed, 8 insertions(+), 36 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
index a86bd3c8..338b3a46 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
@@ -2,46 +2,31 @@ package com.hoc.flowmvi.ui.add
 
 import android.content.Context
 import android.content.Intent
-import android.os.Bundle
 import android.util.Log
 import android.view.MenuItem
-import androidx.appcompat.app.AppCompatActivity
 import androidx.core.view.isInvisible
-import androidx.lifecycle.lifecycleScope
 import androidx.transition.AutoTransition
 import androidx.transition.TransitionManager
 import com.hoc.flowmvi.core.clicks
-import com.hoc.flowmvi.core.collectIn
 import com.hoc.flowmvi.core.firstChange
 import com.hoc.flowmvi.core.navigator.IntentProviders
 import com.hoc.flowmvi.core.textChanges
 import com.hoc.flowmvi.core.toast
-import com.hoc.flowmvi.mvi_base.MviView
+import com.hoc.flowmvi.mvi_base.AbstractMviActivity
 import com.hoc.flowmvi.ui.add.databinding.ActivityAddBinding
 import com.hoc081098.viewbindingdelegate.viewBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.merge
-import kotlinx.coroutines.flow.onEach
 import org.koin.androidx.viewmodel.ext.android.viewModel
 
 @ExperimentalCoroutinesApi
 class AddActivity :
-  AppCompatActivity(R.layout.activity_add),
-  MviView<ViewIntent, ViewState, SingleEvent> {
-  private val addVM by viewModel<AddVM>()
+  AbstractMviActivity<ViewIntent, ViewState, SingleEvent, AddVM>(R.layout.activity_add) {
+  override val vm by viewModel<AddVM>()
   private val addBinding by viewBinding<ActivityAddBinding>()
 
-  override fun onCreate(savedInstanceState: Bundle?) {
-    super.onCreate(savedInstanceState)
-    supportActionBar?.setDisplayHomeAsUpEnabled(true)
-
-    setupViews()
-    bindVM(addVM)
-  }
-
   override fun onOptionsItemSelected(item: MenuItem): Boolean {
     return when (item.itemId) {
       android.R.id.home -> true.also { finish() }
@@ -49,21 +34,6 @@ class AddActivity :
     }
   }
 
-  private fun bindVM(addVM: AddVM) {
-    // observe view model
-    addVM.viewState
-      .collectIn(this) { render(it) }
-
-    // observe single event
-    addVM.singleEvent
-      .collectIn(this) { handleSingleEvent(it) }
-
-    // pass view intent to view model
-    viewIntents()
-      .onEach { addVM.processIntent(it) }
-      .launchIn(lifecycleScope)
-  }
-
   override fun handleSingleEvent(event: SingleEvent) {
     Log.d("###", "Event=$event")
 
@@ -120,8 +90,10 @@ class AddActivity :
     addBinding.addButton.isInvisible = viewState.isLoading
   }
 
-  private fun setupViews() {
-    val state = addVM.viewState.value
+  override fun setupViews() {
+    supportActionBar?.setDisplayHomeAsUpEnabled(true)
+
+    val state = vm.viewState.value
 
     addBinding.run {
       emailEditText.editText!!.setText(state.email)
diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index 6085b421..5347ad34 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -31,7 +31,7 @@ import kotlinx.coroutines.flow.scan
 import kotlinx.coroutines.flow.stateIn
 
 @ExperimentalCoroutinesApi
-internal class AddVM(
+class AddVM(
   private val addUser: AddUserUseCase,
   private val savedStateHandle: SavedStateHandle,
 ) : AbstractMviViewModel<ViewIntent, ViewState, SingleEvent>() {

From b144c1c2d6a4a24fabc45bc8781ec31237ec5de6 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Wed, 3 Nov 2021 22:56:04 +0700
Subject: [PATCH 13/21] AbstractMviActivity

---
 .../com/hoc/flowmvi/ui/add/AddActivity.kt     |  2 +-
 .../hoc/flowmvi/ui/search/SearchActivity.kt   | 34 ++++---------------
 .../com/hoc/flowmvi/ui/search/SearchVM.kt     |  2 +-
 3 files changed, 8 insertions(+), 30 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
index 338b3a46..7ca729a5 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddActivity.kt
@@ -91,7 +91,7 @@ class AddActivity :
   }
 
   override fun setupViews() {
-    supportActionBar?.setDisplayHomeAsUpEnabled(true)
+    supportActionBar!!.setDisplayHomeAsUpEnabled(true)
 
     val state = vm.viewState.value
 
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index efd29c15..558abac9 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -3,11 +3,9 @@ package com.hoc.flowmvi.ui.search
 import android.content.Context
 import android.content.Intent
 import android.content.res.Configuration
-import android.os.Bundle
 import android.util.Log
 import android.view.Menu
 import android.view.MenuItem
-import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.SearchView
 import androidx.core.view.isInvisible
 import androidx.core.view.isVisible
@@ -15,12 +13,11 @@ import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.GridLayoutManager
 import com.hoc.flowmvi.core.SearchViewQueryTextEvent
 import com.hoc.flowmvi.core.clicks
-import com.hoc.flowmvi.core.collectIn
 import com.hoc.flowmvi.core.navigator.IntentProviders
 import com.hoc.flowmvi.core.queryTextEvents
 import com.hoc.flowmvi.core.toast
 import com.hoc.flowmvi.domain.repository.UserError
-import com.hoc.flowmvi.mvi_base.MviView
+import com.hoc.flowmvi.mvi_base.AbstractMviActivity
 import com.hoc.flowmvi.ui.search.databinding.ActivitySearchBinding
 import com.hoc081098.viewbindingdelegate.viewBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -39,34 +36,13 @@ import kotlin.time.ExperimentalTime
 @FlowPreview
 @ExperimentalTime
 class SearchActivity :
-  AppCompatActivity(R.layout.activity_search),
-  MviView<ViewIntent, ViewState, SingleEvent> {
+  AbstractMviActivity<ViewIntent, ViewState, SingleEvent, SearchVM>(R.layout.activity_search) {
   private val binding by viewBinding<ActivitySearchBinding>()
-  private val vm by viewModel<SearchVM>()
+  override val vm by viewModel<SearchVM>()
 
   private val searchViewQueryTextEventChannel = Channel<SearchViewQueryTextEvent>()
   private val searchAdapter = SearchAdapter()
 
-  override fun onCreate(savedInstanceState: Bundle?) {
-    super.onCreate(savedInstanceState)
-    supportActionBar!!.setDisplayHomeAsUpEnabled(true)
-
-    setupViews()
-    bindVM()
-  }
-
-  private fun bindVM() {
-    vm.viewState
-      .collectIn(this) { viewState -> render(viewState) }
-
-    vm.singleEvent
-      .collectIn(this) { event -> handleSingleEvent(event) }
-
-    viewIntents()
-      .onEach { vm.processIntent(it) }
-      .launchIn(lifecycleScope)
-  }
-
   override fun handleSingleEvent(event: SingleEvent) {
     when (event) {
       is SingleEvent.SearchFailure -> toast("Failed to search")
@@ -104,7 +80,9 @@ class SearchActivity :
     binding.retryButton.clicks().map { ViewIntent.Retry },
   )
 
-  private fun setupViews() {
+  override fun setupViews() {
+    supportActionBar!!.setDisplayHomeAsUpEnabled(true)
+
     binding.run {
       usersRecycler.run {
         setHasFixedSize(true)
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
index 92ecc1c4..23bbb88c 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
@@ -31,7 +31,7 @@ import kotlin.time.ExperimentalTime
 @FlowPreview
 @ExperimentalTime
 @ExperimentalCoroutinesApi
-internal class SearchVM(
+class SearchVM(
   private val searchUsersUseCase: SearchUsersUseCase,
 ) : AbstractMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 

From c4c357cabd096aeae67483dabaa7311b0ff9d3f0 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Thu, 4 Nov 2021 02:23:22 +0700
Subject: [PATCH 14/21] Update SearchVM.kt

---
 .../main/java/com/hoc/flowmvi/ui/add/AddVM.kt |  6 ++--
 .../hoc/flowmvi/ui/search/SearchActivity.kt   | 29 ++++++++++++-------
 .../hoc/flowmvi/ui/search/SearchContract.kt   | 20 ++++++++-----
 .../com/hoc/flowmvi/ui/search/SearchModule.kt |  7 ++++-
 .../com/hoc/flowmvi/ui/search/SearchVM.kt     | 24 ++++++++++++---
 5 files changed, 60 insertions(+), 26 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index 5347ad34..f8f20198 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -170,9 +170,9 @@ class AddVM(
   }
 
   private companion object {
-    const val EMAIL_KEY = "email"
-    const val FIRST_NAME_KEY = "first_name"
-    const val LAST_NAME_KEY = "last_name"
+    const val EMAIL_KEY = "com.hoc.flowmvi.ui.add.email"
+    const val FIRST_NAME_KEY = "com.hoc.flowmvi.ui.add.first_name"
+    const val LAST_NAME_KEY = "com.hoc.flowmvi.ui.add.last_name"
 
     const val MIN_LENGTH_FIRST_NAME = 3
     const val MIN_LENGTH_LAST_NAME = 3
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index 558abac9..fa4b6022 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -53,18 +53,22 @@ class SearchActivity :
     searchAdapter.submitList(viewState.users)
 
     binding.run {
-      textQuery.isInvisible = viewState.isLoading || viewState.query.isBlank()
-      textQuery.text = "Search results for '${viewState.query}'"
+      textQuery.isInvisible = viewState.isLoading || viewState.submittedQuery.isBlank()
+      if (textQuery.isVisible) {
+        textQuery.text = "Search results for '${viewState.submittedQuery}'"
+      }
 
       errorGroup.isVisible = viewState.error !== null
-      errorMessageTextView.text = viewState.error?.let {
-        when (it) {
-          is UserError.InvalidId -> "Invalid id"
-          UserError.NetworkError -> "Network error"
-          UserError.ServerError -> "Server error"
-          UserError.Unexpected -> "Unexpected error"
-          is UserError.UserNotFound -> "User not found"
-          UserError.ValidationFailed -> "Validation failed"
+      if (errorGroup.isVisible) {
+        errorMessageTextView.text = viewState.error?.let {
+          when (it) {
+            is UserError.InvalidId -> "Invalid id"
+            UserError.NetworkError -> "Network error"
+            UserError.ServerError -> "Server error"
+            UserError.Unexpected -> "Unexpected error"
+            is UserError.UserNotFound -> "User not found"
+            UserError.ValidationFailed -> "Validation failed"
+          }
         }
       }
 
@@ -109,6 +113,11 @@ class SearchActivity :
       isIconified = false
       queryHint = "Search user..."
 
+      vm.viewState.value
+        .originalQuery
+        .takeUnless { it.isNullOrBlank() }
+        ?.let { setQuery(it, false) }
+
       queryTextEvents()
         .onEach { searchViewQueryTextEventChannel.send(it) }
         .launchIn(lifecycleScope)
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
index 7bca2eac..a7990547 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
@@ -36,15 +36,17 @@ data class ViewState(
   val users: List<UserItem>,
   val isLoading: Boolean,
   val error: UserError?,
-  val query: String,
+  val submittedQuery: String,
+  val originalQuery: String?,
 ) : MviViewState {
   companion object Factory {
-    fun initial(): ViewState {
+    fun initial(originalQuery: String?): ViewState {
       return ViewState(
         users = emptyList(),
         isLoading = false,
         error = null,
-        query = "",
+        submittedQuery = "",
+        originalQuery = originalQuery,
       )
     }
   }
@@ -52,14 +54,15 @@ data class ViewState(
 
 internal sealed interface PartialStateChange {
   object Loading : PartialStateChange
-  data class Success(val users: List<UserItem>, val query: String) : PartialStateChange
-  data class Failure(val error: UserError, val query: String) : PartialStateChange
+  data class Success(val users: List<UserItem>, val submittedQuery: String) : PartialStateChange
+  data class Failure(val error: UserError, val submittedQuery: String) : PartialStateChange
+  data class QueryChanged(val query: String) : PartialStateChange
 
-  fun reduce(state: ViewState) = when (this) {
+  fun reduce(state: ViewState): ViewState = when (this) {
     is Failure -> state.copy(
       isLoading = false,
       error = error,
-      query = query,
+      submittedQuery = submittedQuery,
       users = emptyList()
     )
     Loading -> state.copy(isLoading = true, error = null)
@@ -67,8 +70,9 @@ internal sealed interface PartialStateChange {
       isLoading = false,
       error = null,
       users = users,
-      query = query,
+      submittedQuery = submittedQuery,
     )
+    is QueryChanged -> state.copy(originalQuery = query)
   }
 }
 
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchModule.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchModule.kt
index 1757ccd7..38b1c6d7 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchModule.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchModule.kt
@@ -13,5 +13,10 @@ import kotlin.time.ExperimentalTime
 val searchModule = module {
   single<IntentProviders.Search> { SearchActivity.IntentProvider() }
 
-  viewModel { SearchVM(searchUsersUseCase = get()) }
+  viewModel { params ->
+    SearchVM(
+      searchUsersUseCase = get(),
+      savedStateHandle = params.get(),
+    )
+  }
 }
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
index 23bbb88c..9a7145fd 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
@@ -1,6 +1,7 @@
 package com.hoc.flowmvi.ui.search
 
 import android.util.Log
+import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.viewModelScope
 import com.hoc.flowmvi.domain.usecase.SearchUsersUseCase
 import com.hoc.flowmvi.mvi_base.AbstractMviViewModel
@@ -33,12 +34,15 @@ import kotlin.time.ExperimentalTime
 @ExperimentalCoroutinesApi
 class SearchVM(
   private val searchUsersUseCase: SearchUsersUseCase,
+  private val savedStateHandle: SavedStateHandle,
 ) : AbstractMviViewModel<ViewIntent, ViewState, SingleEvent>() {
 
   override val viewState: StateFlow<ViewState>
 
   init {
-    val initialVS = ViewState.initial()
+    val initialVS = ViewState.initial(
+      originalQuery = savedStateHandle.get<String?>(QUERY_KEY)
+    )
 
     viewState = intentFlow
       .toPartialStateChangesFlow()
@@ -66,21 +70,25 @@ class SearchVM(
     }
 
     val queryFlow = filterIsInstance<ViewIntent.Search>()
-      .debounce(Duration.milliseconds(400))
       .map { it.query }
+      .shareWhileSubscribed()
+
+    val searchableQueryFlow = queryFlow
+      .debounce(Duration.milliseconds(400))
       .filter { it.isNotBlank() }
       .distinctUntilChanged()
       .shareWhileSubscribed()
 
     return merge(
-      queryFlow.flatMapLatest(executeSearch),
+      searchableQueryFlow.flatMapLatest(executeSearch),
       filterIsInstance<ViewIntent.Retry>()
         .flatMapFirst {
           viewState.value.let { vs ->
-            if (vs.error !== null) executeSearch(vs.query).takeUntil(queryFlow)
+            if (vs.error !== null) executeSearch(vs.submittedQuery).takeUntil(searchableQueryFlow)
             else emptyFlow()
           }
         },
+      queryFlow.map { PartialStateChange.QueryChanged(it) },
     )
   }
 
@@ -90,6 +98,14 @@ class SearchVM(
         is PartialStateChange.Failure -> sendEvent(SingleEvent.SearchFailure(change.error))
         PartialStateChange.Loading -> return@onEach
         is PartialStateChange.Success -> return@onEach
+        is PartialStateChange.QueryChanged -> {
+          savedStateHandle.set(QUERY_KEY, change.query)
+          return@onEach
+        }
       }
     }
+
+  private companion object {
+    const val QUERY_KEY = "com.hoc.flowmvi.ui.search.query"
+  }
 }

From 45e3b54049a21cd7979609ccdbfd2851e691e794 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petrus=20Nguy=E1=BB=85n=20Th=C3=A1i=20H=E1=BB=8Dc?=
 <hoc081098@gmail.com>
Date: Thu, 4 Nov 2021 19:38:43 +0700
Subject: [PATCH 15/21] cache

---
 .github/workflows/build.yml                   | 12 +++++++++++-
 .github/workflows/gradle-versions-checker.yml | 10 ++++++++++
 .github/workflows/review-suggest.yml          |  9 +++++++++
 .github/workflows/unit-test.yml               | 10 ++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 856c2d43..ad1e48d7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -12,12 +12,22 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
-      - name: Set up JDKd
+      - name: Set up JDK
         uses: actions/setup-java@v2
         with:
           distribution: 'zulu'
           java-version: '11'
 
+      - name: Cache gradle, wrapper and buildSrc
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-${{ github.job }}-${{ hashFiles('**/*.gradle*') }}-${{ hashFiles('**/gradle/wrapper/gradle-wrapper.properties') }}-${{ hashFiles('**/buildSrc/**/*.kt') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ github.job }}-
+
       - name: Make gradlew executable
         run: chmod +x ./gradlew
 
diff --git a/.github/workflows/gradle-versions-checker.yml b/.github/workflows/gradle-versions-checker.yml
index 6345b8ba..e6580614 100644
--- a/.github/workflows/gradle-versions-checker.yml
+++ b/.github/workflows/gradle-versions-checker.yml
@@ -21,6 +21,16 @@ jobs:
           distribution: 'zulu'
           java-version: '11'
 
+      - name: Cache gradle, wrapper and buildSrc
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-${{ github.job }}-${{ hashFiles('**/*.gradle*') }}-${{ hashFiles('**/gradle/wrapper/gradle-wrapper.properties') }}-${{ hashFiles('**/buildSrc/**/*.kt') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ github.job }}-
+
       - name: Make gradlew executable
         run: chmod +x ./gradlew
 
diff --git a/.github/workflows/review-suggest.yml b/.github/workflows/review-suggest.yml
index 4388e9e1..d06d0ddd 100644
--- a/.github/workflows/review-suggest.yml
+++ b/.github/workflows/review-suggest.yml
@@ -15,6 +15,15 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: '11'
+      - name: Cache gradle, wrapper and buildSrc
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-${{ github.job }}-${{ hashFiles('**/*.gradle*') }}-${{ hashFiles('**/gradle/wrapper/gradle-wrapper.properties') }}-${{ hashFiles('**/buildSrc/**/*.kt') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ github.job }}-
       - name: Make gradlew executable
         run: chmod +x ./gradlew
       - run: ./gradlew spotlessKotlinApply
diff --git a/.github/workflows/unit-test.yml b/.github/workflows/unit-test.yml
index df9e4c0d..9ad2da3b 100644
--- a/.github/workflows/unit-test.yml
+++ b/.github/workflows/unit-test.yml
@@ -18,6 +18,16 @@ jobs:
           distribution: 'zulu'
           java-version: '11'
 
+      - name: Cache gradle, wrapper and buildSrc
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-${{ github.job }}-${{ hashFiles('**/*.gradle*') }}-${{ hashFiles('**/gradle/wrapper/gradle-wrapper.properties') }}-${{ hashFiles('**/buildSrc/**/*.kt') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ github.job }}-
+
       - name: Make gradlew executable
         run: chmod +x ./gradlew
 

From 8687afb13c070cc993b5434be70ae4a0d5869441 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Thu, 4 Nov 2021 19:49:36 +0700
Subject: [PATCH 16/21] chore: using indexing operator instead of `set`

---
 feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt   | 6 +++---
 .../src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt     | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index f8f20198..14793bde 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -68,15 +68,15 @@ class AddVM(
         PartialStateChange.FirstChange.FirstNameChangedFirstTime -> return@onEach
         PartialStateChange.FirstChange.LastNameChangedFirstTime -> return@onEach
         is PartialStateChange.FormValueChange.EmailChanged -> {
-          savedStateHandle.set(EMAIL_KEY, change.email)
+          savedStateHandle[EMAIL_KEY] = change.email
           return@onEach
         }
         is PartialStateChange.FormValueChange.FirstNameChanged -> {
-          savedStateHandle.set(FIRST_NAME_KEY, change.firstName)
+          savedStateHandle[FIRST_NAME_KEY] = change.firstName
           return@onEach
         }
         is PartialStateChange.FormValueChange.LastNameChanged -> {
-          savedStateHandle.set(LAST_NAME_KEY, change.lastName)
+          savedStateHandle[LAST_NAME_KEY] = change.lastName
           return@onEach
         }
       }
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
index 9a7145fd..09502905 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
@@ -99,7 +99,7 @@ class SearchVM(
         PartialStateChange.Loading -> return@onEach
         is PartialStateChange.Success -> return@onEach
         is PartialStateChange.QueryChanged -> {
-          savedStateHandle.set(QUERY_KEY, change.query)
+          savedStateHandle[QUERY_KEY] = change.query
           return@onEach
         }
       }

From bfee0c27eb76430ceeebb7189becfc905ca8cb01 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Thu, 4 Nov 2021 20:13:46 +0700
Subject: [PATCH 17/21] update SearchActivity

---
 .../hoc/flowmvi/ui/search/SearchActivity.kt   | 30 +++++++++++--------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index fa4b6022..8b35599b 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -109,18 +109,24 @@ class SearchActivity :
   override fun onCreateOptionsMenu(menu: Menu): Boolean {
     menuInflater.inflate(R.menu.menu_search, menu)
 
-    (menu.findItem(R.id.action_search)!!.actionView as SearchView).run {
-      isIconified = false
-      queryHint = "Search user..."
-
-      vm.viewState.value
-        .originalQuery
-        .takeUnless { it.isNullOrBlank() }
-        ?.let { setQuery(it, false) }
-
-      queryTextEvents()
-        .onEach { searchViewQueryTextEventChannel.send(it) }
-        .launchIn(lifecycleScope)
+    menu.findItem(R.id.action_search)!!.let { menuItem ->
+      (menuItem.actionView as SearchView).run {
+        isIconified = false
+        queryHint = "Search user..."
+
+        vm.viewState.value
+          .originalQuery
+          .takeUnless { it.isNullOrBlank() }
+          ?.let {
+            menuItem.expandActionView()
+            setQuery(it, true)
+            clearFocus()
+          }
+
+        queryTextEvents()
+          .onEach { searchViewQueryTextEventChannel.send(it) }
+          .launchIn(lifecycleScope)
+      }
     }
 
     return true

From 801f32c47a9ea86136375cec593a95f441b875b0 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Thu, 4 Nov 2021 20:38:30 +0700
Subject: [PATCH 18/21] fix SearchActivity

---
 .../hoc/flowmvi/ui/search/SearchActivity.kt   | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index 8b35599b..3cfe489e 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -16,6 +16,7 @@ import com.hoc.flowmvi.core.clicks
 import com.hoc.flowmvi.core.navigator.IntentProviders
 import com.hoc.flowmvi.core.queryTextEvents
 import com.hoc.flowmvi.core.toast
+import com.hoc.flowmvi.core.unit
 import com.hoc.flowmvi.domain.repository.UserError
 import com.hoc.flowmvi.mvi_base.AbstractMviActivity
 import com.hoc.flowmvi.ui.search.databinding.ActivitySearchBinding
@@ -114,18 +115,24 @@ class SearchActivity :
         isIconified = false
         queryHint = "Search user..."
 
+        fun listen() = queryTextEvents()
+          .onEach { searchViewQueryTextEventChannel.send(it) }
+          .launchIn(lifecycleScope)
+          .unit
+
         vm.viewState.value
           .originalQuery
           .takeUnless { it.isNullOrBlank() }
           ?.let {
-            menuItem.expandActionView()
-            setQuery(it, true)
-            clearFocus()
-          }
+            post {
+              menuItem.expandActionView()
+              setQuery(it, true)
+              clearFocus()
 
-        queryTextEvents()
-          .onEach { searchViewQueryTextEventChannel.send(it) }
-          .launchIn(lifecycleScope)
+              listen()
+            }
+          }
+          ?: listen()
       }
     }
 

From 74e67f82d6f94480f2b4e7b6b11c4271d518a448 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Fri, 5 Nov 2021 00:07:28 +0700
Subject: [PATCH 19/21] fix SearchActivity

---
 core/src/main/java/com/hoc/flowmvi/core/FlowBinding.kt |  1 -
 .../src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt      | 10 ++++++----
 .../java/com/hoc/flowmvi/ui/search/SearchContract.kt   |  2 +-
 .../main/java/com/hoc/flowmvi/ui/search/SearchVM.kt    |  4 +++-
 feature-search/src/main/res/menu/menu_search.xml       |  2 +-
 5 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/core/src/main/java/com/hoc/flowmvi/core/FlowBinding.kt b/core/src/main/java/com/hoc/flowmvi/core/FlowBinding.kt
index 9b7903c2..4d2cccf5 100644
--- a/core/src/main/java/com/hoc/flowmvi/core/FlowBinding.kt
+++ b/core/src/main/java/com/hoc/flowmvi/core/FlowBinding.kt
@@ -118,7 +118,6 @@ fun EditText.textChanges(): Flow<CharSequence?> {
     checkMainThread()
 
     val listener = doOnTextChanged { text, _, _, _ -> trySend(text) }
-    addTextChangedListener(listener)
     awaitClose { removeTextChangedListener(listener) }
   }.onStart { emit(text) }
 }
diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
index 14793bde..67d5616d 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddVM.kt
@@ -12,9 +12,11 @@ import com.hoc.flowmvi.domain.entity.User
 import com.hoc.flowmvi.domain.usecase.AddUserUseCase
 import com.hoc.flowmvi.mvi_base.AbstractMviViewModel
 import com.hoc081098.flowext.flatMapFirst
+import com.hoc081098.flowext.mapTo
 import com.hoc081098.flowext.withLatestFrom
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
@@ -84,7 +86,7 @@ class AddVM(
     }
   }
 
-  private fun Flow<ViewIntent>.toPartialStateChangesFlow(): Flow<PartialStateChange> {
+  private fun SharedFlow<ViewIntent>.toPartialStateChangesFlow(): Flow<PartialStateChange> {
     val emailFlow = filterIsInstance<ViewIntent.EmailChanged>()
       .log("Intent")
       .map { it.email }
@@ -137,13 +139,13 @@ class AddVM(
     val firstChanges = merge(
       filterIsInstance<ViewIntent.EmailChangedFirstTime>()
         .log("Intent")
-        .map { PartialStateChange.FirstChange.EmailChangedFirstTime },
+        .mapTo(PartialStateChange.FirstChange.EmailChangedFirstTime),
       filterIsInstance<ViewIntent.FirstNameChangedFirstTime>()
         .log("Intent")
-        .map { PartialStateChange.FirstChange.FirstNameChangedFirstTime },
+        .mapTo(PartialStateChange.FirstChange.FirstNameChangedFirstTime),
       filterIsInstance<ViewIntent.LastNameChangedFirstTime>()
         .log("Intent")
-        .map { PartialStateChange.FirstChange.LastNameChangedFirstTime }
+        .mapTo(PartialStateChange.FirstChange.LastNameChangedFirstTime)
     )
 
     val formValuesChanges = merge(
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
index a7990547..9c0d3316 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
@@ -72,7 +72,7 @@ internal sealed interface PartialStateChange {
       users = users,
       submittedQuery = submittedQuery,
     )
-    is QueryChanged -> state.copy(originalQuery = query)
+    is QueryChanged -> if (state.originalQuery == query) state else state.copy(originalQuery = query)
   }
 }
 
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
index 09502905..278f7955 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
@@ -10,6 +10,7 @@ import com.hoc081098.flowext.takeUntil
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
@@ -52,7 +53,7 @@ class SearchVM(
       .stateIn(viewModelScope, SharingStarted.Eagerly, initialVS)
   }
 
-  private fun Flow<ViewIntent>.toPartialStateChangesFlow(): Flow<PartialStateChange> {
+  private fun SharedFlow<ViewIntent>.toPartialStateChangesFlow(): Flow<PartialStateChange> {
     val executeSearch: suspend (String) -> Flow<PartialStateChange> = { query: String ->
       flow { emit(searchUsersUseCase(query)) }
         .map { result ->
@@ -70,6 +71,7 @@ class SearchVM(
     }
 
     val queryFlow = filterIsInstance<ViewIntent.Search>()
+      .log("Intent")
       .map { it.query }
       .shareWhileSubscribed()
 
diff --git a/feature-search/src/main/res/menu/menu_search.xml b/feature-search/src/main/res/menu/menu_search.xml
index 2f131243..30027c2d 100644
--- a/feature-search/src/main/res/menu/menu_search.xml
+++ b/feature-search/src/main/res/menu/menu_search.xml
@@ -7,5 +7,5 @@
     android:icon="@drawable/ic_baseline_search_24"
     android:title="Search"
     app:actionViewClass="androidx.appcompat.widget.SearchView"
-    app:showAsAction="always|collapseActionView" />
+    app:showAsAction="always" />
 </menu>

From b3346d969b4ee89ae92b98f8b2e3ccdf58c08065 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Fri, 5 Nov 2021 00:17:59 +0700
Subject: [PATCH 20/21] some fixes

---
 .../com/hoc/flowmvi/ui/add/AddContract.kt     | 16 ++++++++++----
 .../hoc/flowmvi/ui/search/SearchActivity.kt   | 21 +++++++------------
 .../hoc/flowmvi/ui/search/SearchContract.kt   |  5 ++++-
 3 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt
index 6fdb2788..c65c0ef7 100644
--- a/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt
+++ b/feature-add/src/main/java/com/hoc/flowmvi/ui/add/AddContract.kt
@@ -35,7 +35,6 @@ data class ViewState(
       lastName: String?,
     ) = ViewState(
       errors = emptySet(),
-
       isLoading = false,
       emailChanged = false,
       firstNameChanged = false,
@@ -97,9 +96,18 @@ internal sealed interface PartialStateChange {
   sealed class FormValueChange : PartialStateChange {
     override fun reduce(viewState: ViewState): ViewState {
       return when (this) {
-        is EmailChanged -> viewState.copy(email = email)
-        is FirstNameChanged -> viewState.copy(firstName = firstName)
-        is LastNameChanged -> viewState.copy(lastName = lastName)
+        is EmailChanged -> {
+          if (viewState.email == email) viewState
+          else viewState.copy(email = email)
+        }
+        is FirstNameChanged -> {
+          if (viewState.firstName == firstName) viewState
+          else viewState.copy(firstName = firstName)
+        }
+        is LastNameChanged -> {
+          if (viewState.lastName == lastName) viewState
+          else viewState.copy(lastName = lastName)
+        }
       }
     }
 
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index 3cfe489e..8b35599b 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -16,7 +16,6 @@ import com.hoc.flowmvi.core.clicks
 import com.hoc.flowmvi.core.navigator.IntentProviders
 import com.hoc.flowmvi.core.queryTextEvents
 import com.hoc.flowmvi.core.toast
-import com.hoc.flowmvi.core.unit
 import com.hoc.flowmvi.domain.repository.UserError
 import com.hoc.flowmvi.mvi_base.AbstractMviActivity
 import com.hoc.flowmvi.ui.search.databinding.ActivitySearchBinding
@@ -115,24 +114,18 @@ class SearchActivity :
         isIconified = false
         queryHint = "Search user..."
 
-        fun listen() = queryTextEvents()
-          .onEach { searchViewQueryTextEventChannel.send(it) }
-          .launchIn(lifecycleScope)
-          .unit
-
         vm.viewState.value
           .originalQuery
           .takeUnless { it.isNullOrBlank() }
           ?.let {
-            post {
-              menuItem.expandActionView()
-              setQuery(it, true)
-              clearFocus()
-
-              listen()
-            }
+            menuItem.expandActionView()
+            setQuery(it, true)
+            clearFocus()
           }
-          ?: listen()
+
+        queryTextEvents()
+          .onEach { searchViewQueryTextEventChannel.send(it) }
+          .launchIn(lifecycleScope)
       }
     }
 
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
index 9c0d3316..6c3f3d35 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
@@ -72,7 +72,10 @@ internal sealed interface PartialStateChange {
       users = users,
       submittedQuery = submittedQuery,
     )
-    is QueryChanged -> if (state.originalQuery == query) state else state.copy(originalQuery = query)
+    is QueryChanged -> {
+      if (state.originalQuery == query) state
+      else state.copy(originalQuery = query)
+    }
   }
 }
 

From 4a9f804cb8afd49dba4b47e67f92eae8c7881ce1 Mon Sep 17 00:00:00 2001
From: Petrus Nguyen Thai Hoc <hoc081098@gmail.com>
Date: Fri, 5 Nov 2021 00:24:21 +0700
Subject: [PATCH 21/21] some fixes

---
 .../main/java/com/hoc/flowmvi/ui/search/SearchContract.kt   | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
index 6c3f3d35..d970eb30 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchContract.kt
@@ -65,7 +65,11 @@ internal sealed interface PartialStateChange {
       submittedQuery = submittedQuery,
       users = emptyList()
     )
-    Loading -> state.copy(isLoading = true, error = null)
+    Loading -> state.copy(
+      isLoading = true,
+      error = null,
+      users = emptyList()
+    )
     is Success -> state.copy(
       isLoading = false,
       error = null,