Throw specific exception when disconnected while waiting for frames

Resolves:
#379

krossbow-stomp-core/src/commonMain/kotlin/org/hildan/krossbow/stomp/BaseStompSession.kt

@@ -154,7 +154,7 @@ internal class BaseStompSession(
                 .dematerializeErrorsAndCompletion()
                 .filterIsInstance<StompFrame.Receipt>()
                 .firstOrNull { it.headers.receiptId == receiptId }
-                    ?: error("Frames flow closed unexpectedly while waiting for RECEIPT frame with id='$receiptId'")
+                ?: throw SessionDisconnectedException("The STOMP frames flow completed unexpectedly while waiting for RECEIPT frame with id='$receiptId'")
         } ?: throw LostReceiptException(receiptId, frame.receiptTimeout, frame)
     }
 

krossbow-stomp-core/src/commonMain/kotlin/org/hildan/krossbow/stomp/StompExceptions.kt

@@ -35,3 +35,8 @@ class WebSocketClosedUnexpectedly(
     val code: Int,
     val reason: String?,
 ) : Exception("the WebSocket was closed while subscriptions were still active. Code: $code Reason: $reason")
+
+/**
+ * An exception thrown when the STOMP frames flow completed while some consumer was expecting more frames.
+ */
+class SessionDisconnectedException(message: String) : Exception(message)

krossbow-stomp-core/src/commonTest/kotlin/org/hildan/krossbow/stomp/StompSessionReceiptTests.kt

@@ -21,6 +21,7 @@ import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.Duration.Companion.minutes
 
 private val TEST_RECEIPT_TIMEOUT: Duration = 500.milliseconds
 
@@ -121,6 +122,26 @@ class StompSessionReceiptTests {
         assertEquals("because why not", exception.reason)
     }
 
+    @Test
+    fun send_autoReceipt_failsOnSessionDisconnected() = runTest {
+        val (wsSession, stompSession) = connectWithMocks {
+            autoReceipt = true
+            receiptTimeout = 5.minutes
+        }
+        launch {
+            wsSession.awaitSendFrameAndSimulateCompletion()
+            // we simulate a disconnection between the SEND and the RECEIPT
+            launch {
+                wsSession.awaitDisconnectFrameAndSimulateCompletion()
+                wsSession.expectClose()
+            }
+            stompSession.disconnect()
+        }
+        assertFailsWith(SessionDisconnectedException::class) {
+            stompSession.sendEmptyMsg("/destination")
+        }
+    }
+
     @Test
     fun send_manualReceipt_waitsForCorrectReceipt() = runTest {
         val (wsSession, stompSession) = connectWithMocks()