From 394b3d816e995d673e8ebfe0b867a170085502e6 Mon Sep 17 00:00:00 2001
From: Richard Myers <remyers@yakshaver.org>
Date: Wed, 8 Nov 2023 15:08:40 +0100
Subject: [PATCH] Update Peer to notify all channels that a peer was
 disconnected

 - Is this necessary? will closing the socket always cause a `Disconnected` message to be sent to the Peer?
---
 .../kotlin/fr/acinq/lightning/io/Peer.kt      |  3 ++-
 .../acinq/lightning/io/peer/ConnectionTest.kt | 19 ++++++++++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/commonMain/kotlin/fr/acinq/lightning/io/Peer.kt b/src/commonMain/kotlin/fr/acinq/lightning/io/Peer.kt
index ea7b09962..717aa68fa 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/io/Peer.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/io/Peer.kt
@@ -287,9 +287,10 @@ class Peer(
         }
     }
 
-    fun disconnect() {
+    suspend fun disconnect() {
         if (this::socket.isInitialized) socket.close()
         _connectionState.value = Connection.CLOSED(null)
+        input.send(Disconnected)
     }
 
     // Warning : lateinit vars have to be used AFTER their init to avoid any crashes
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/io/peer/ConnectionTest.kt b/src/commonTest/kotlin/fr/acinq/lightning/io/peer/ConnectionTest.kt
index ca2e86f5a..b12d4c03f 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/io/peer/ConnectionTest.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/io/peer/ConnectionTest.kt
@@ -1,13 +1,17 @@
 package fr.acinq.lightning.io.peer
 
-import fr.acinq.lightning.channel.states.Offline
+import fr.acinq.lightning.Lightning
 import fr.acinq.lightning.channel.TestsHelper.reachNormal
+import fr.acinq.lightning.channel.states.Offline
 import fr.acinq.lightning.io.Disconnected
+import fr.acinq.lightning.io.MessageReceived
 import fr.acinq.lightning.tests.TestConstants
 import fr.acinq.lightning.tests.io.peer.newPeer
 import fr.acinq.lightning.tests.utils.LightningTestSuite
 import fr.acinq.lightning.tests.utils.runSuspendTest
 import fr.acinq.lightning.utils.Connection
+import fr.acinq.lightning.wire.Stfu
+import fr.acinq.lightning.wire.UpdateFulfillHtlc
 import kotlinx.coroutines.flow.first
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -25,4 +29,17 @@ class ConnectionTest : LightningTestSuite() {
         assertEquals(Connection.ESTABLISHED, peer.connectionState.value)
     }
 
+    @Test
+    fun `channel triggers a disconnect from a peer`() = runSuspendTest {
+        val (alice0, bob0) = reachNormal()
+        val peer = newPeer(alice0.staticParams.nodeParams, TestConstants.Alice.walletParams, bob0) { channels.addOrUpdateChannel(alice0.state) }
+
+        // alice disconnects from bob if bob sends a forbidden message after stfu
+        peer.send(MessageReceived(0, Stfu(alice0.channelId, true)) )
+        peer.send(MessageReceived(0, UpdateFulfillHtlc(alice0.channelId, 0, Lightning.randomBytes32()) ))
+        // Wait until alice is Offline
+        peer.channelsFlow.first { it.values.size == 1 && it.values.all { channelState -> channelState is Offline } }
+        assertEquals(Connection.CLOSED(null), peer.connectionState.value)
+    }
+
 }
\ No newline at end of file