fix(IRC): handle socket disconnected error when leaving last room (#16)

Sources/Twitch/IRC/IRCConnection.swift

@@ -54,7 +54,18 @@ internal actor IRCConnection {
           }
         }
       } catch {
-        continuation.finish(throwing: error)
+        // If we get the 'socket disconnected' error, check whether we have parted from all rooms.
+        // Doing so is what causes us to get this error on the next websocket.receive() call
+        let nsError = error as NSError
+        if nsError.domain == "NSPOSIXErrorDomain", nsError.code == 57,
+          joinedChannels.isEmpty
+        {
+          continuation.finish()
+        } else {
+          // If we can't identify the origin of the error, return it in the stream to be hanlded upstream
+          continuation.finish(throwing: error)
+        }
+
         self.disconnect()
       }
     }

Sources/Twitch/IRC/IRCConnectionPool.swift

@@ -83,8 +83,12 @@ public actor IRCConnectionPool {
     let messageStream = try await connection.connect()
 
     Task {
-      for try await message in messageStream {
-        self.continuation?.yield(message)
+      do {
+        for try await message in messageStream {
+          self.continuation?.yield(message)
+        }
+      } catch {
+        self.continuation?.finish(throwing: error)
       }
     }