From 8b39882e834aba1692675a70baa427691bdda346 Mon Sep 17 00:00:00 2001
From: InsanusMokrassar <ovsyannikov.alexey95@gmail.com>
Date: Mon, 27 Dec 2021 15:57:55 +0600
Subject: [PATCH] fixes in DefaultUpdatableStatesMachine

---
 CHANGELOG.md                                                | 3 +++
 .../inmo/micro_utils/fsm/common/UpdatableStatesMachine.kt   | 6 ++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 007b5c2d1a2..f538f5039bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@
     * `Server`:
         * Fixes in `uniloadMultipart`
 
+* `FSM`:
+    * Fixes in `DefaultUpdatableStatesMachine`
+
 ## 0.8.8
 
 * `Versions`:
diff --git a/fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/UpdatableStatesMachine.kt b/fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/UpdatableStatesMachine.kt
index deadfb62324..76fccd49c88 100644
--- a/fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/UpdatableStatesMachine.kt
+++ b/fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/UpdatableStatesMachine.kt
@@ -28,12 +28,12 @@ open class DefaultUpdatableStatesMachine<T : State>(
 
     override suspend fun performStateUpdate(previousState: Optional<T>, actualState: T, scope: CoroutineScope) {
         statesJobsMutex.withLock {
-            if (previousState.dataOrNull() != actualState) {
+            if (compare(previousState, actualState)) {
                 statesJobs[actualState] ?.cancel()
             }
             val job = previousState.mapOnPresented {
                 statesJobs.remove(it)
-            } ?: scope.launch {
+            } ?.takeIf { it.isActive } ?: scope.launch {
                 performUpdate(actualState)
             }.also { job ->
                 job.invokeOnCompletion { _ ->
@@ -52,6 +52,8 @@ open class DefaultUpdatableStatesMachine<T : State>(
         }
     }
 
+    protected suspend fun compare(previous: Optional<T>, new: T): Boolean = previous.dataOrNull() != new
+
     override suspend fun updateChain(currentState: T, newState: T) {
         statesManager.update(currentState, newState)
     }