From 484c0a246a39fd1a62022ce5102472eca0f65bc3 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: Tue, 5 Mar 2024 20:25:32 +0700
Subject: [PATCH] fix(autoclose): close `Closeable`s in reversed order (#3387)

* fix(autoclose): close closeables in reversed order
issue https://github.com/arrow-kt/arrow/issues/3386

* fix(autoclose): close closeables in reversed order
issue https://github.com/arrow-kt/arrow/issues/3386

* fix test: suppressedExceptions
---
 .../commonMain/kotlin/arrow/AutoCloseScope.kt |  2 +-
 .../commonTest/kotlin/arrow/AutoCloseTest.kt  | 40 ++++++++++++++++++-
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/arrow-libs/core/arrow-autoclose/src/commonMain/kotlin/arrow/AutoCloseScope.kt b/arrow-libs/core/arrow-autoclose/src/commonMain/kotlin/arrow/AutoCloseScope.kt
index 219d853c716..d42f23cd54d 100644
--- a/arrow-libs/core/arrow-autoclose/src/commonMain/kotlin/arrow/AutoCloseScope.kt
+++ b/arrow-libs/core/arrow-autoclose/src/commonMain/kotlin/arrow/AutoCloseScope.kt
@@ -98,7 +98,7 @@ internal class DefaultAutoCloseScope : AutoCloseScope {
     }
 
   fun close(error: Throwable?): Nothing? {
-    return finalizers.get().fold(error) { acc, function ->
+    return finalizers.get().asReversed().fold(error) { acc, function ->
       acc.add(runCatching { function.invoke(error) }.exceptionOrNull())
     }?.let { throw it }
   }
diff --git a/arrow-libs/core/arrow-autoclose/src/commonTest/kotlin/arrow/AutoCloseTest.kt b/arrow-libs/core/arrow-autoclose/src/commonTest/kotlin/arrow/AutoCloseTest.kt
index 85ccd7966e2..2dc8d63d192 100644
--- a/arrow-libs/core/arrow-autoclose/src/commonTest/kotlin/arrow/AutoCloseTest.kt
+++ b/arrow-libs/core/arrow-autoclose/src/commonTest/kotlin/arrow/AutoCloseTest.kt
@@ -4,6 +4,8 @@ import arrow.atomic.AtomicBoolean
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.matchers.shouldBe
 import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.channels.toList
 import kotlinx.coroutines.test.runTest
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.test.Test
@@ -76,7 +78,7 @@ class AutoCloseTest {
     }
 
     e shouldBe error
-    e.suppressedExceptions shouldBe listOf(error2, error3)
+    e.suppressedExceptions shouldBe listOf(error3, error2)
     promise.await() shouldBe error
     wasActive.await() shouldBe true
     res.isActive() shouldBe false
@@ -134,6 +136,42 @@ class AutoCloseTest {
     res.isActive() shouldBe false
   }
 
+  @Test
+  fun closeInReversedOrder() = runTest {
+    val res1 = Resource()
+    val res2 = Resource()
+    val res3 = Resource()
+
+    val wasActive = Channel<Boolean>(Channel.UNLIMITED)
+    val closed = Channel<Resource>(Channel.UNLIMITED)
+
+    autoCloseScope {
+      val r1 = autoClose({ res1 }) { r, _ ->
+        closed.trySend(r).getOrThrow()
+        r.shutdown()
+      }
+      val r2 = autoClose({ res2 }) { r, _ ->
+        closed.trySend(r).getOrThrow()
+        r.shutdown()
+      }
+      val r3 = autoClose({ res3 }) { r, _ ->
+        closed.trySend(r).getOrThrow()
+        r.shutdown()
+      }
+
+      wasActive.trySend(r1.isActive()).getOrThrow()
+      wasActive.trySend(r2.isActive()).getOrThrow()
+      wasActive.trySend(r3.isActive()).getOrThrow()
+      wasActive.close()
+    }
+
+    wasActive.toList() shouldBe listOf(true, true, true)
+    closed.receive() shouldBe res3
+    closed.receive() shouldBe res2
+    closed.receive() shouldBe res1
+    closed.cancel()
+  }
+
   @OptIn(ExperimentalStdlibApi::class)
   private class Resource : AutoCloseable {
     private val isActive = AtomicBoolean(true)