Handle virtual links in Link._clearPendingRequests

When a request is forwarded from a virtual link to a WebSocket link as
is the case when an instance sends a request to the controller the
origin for the request is a virtual link.  Handle this case in
_clearPendingRequests instead of throwing an assertion error.

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Fixed controller only plugins throwing an error about missing a config field on startup out when added to hosts.
 - Fixed installer incorrectly claiming the options --factorio-dir and --no-download-headless conflicts with each other.
 - Fixed a memory leak on every request sent over the WebSocket.
+- Fixed assertion error on closing or invalidating a link with messages forwarded from a virtual link.
 
 
 ## Version 2.0.0-alpha.14

packages/lib/src/link/link.ts

@@ -153,12 +153,18 @@ export class Link {
 			pending.reject(err);
 		}
 		for (let pending of this._forwardedRequests.values()) {
-			assert(pending.origin.connector instanceof WebSocketBaseConnector);
-			if (pending.origin.connector.hasSession) {
-				pending.origin.connector.sendResponseError(
-					new libData.ResponseError(err.message, err.code), pending.src, pending.dst
-				);
+			// Drop response if the origin is a WebSocket and the session
+			// has expired.  The other end of the link will have sent an
+			// error response to the request in this case.
+			if (
+				pending.origin.connector instanceof WebSocketBaseConnector
+				&& !pending.origin.connector.hasSession
+			) {
+				continue;
 			}
+			pending.origin.connector.sendResponseError(
+				new libData.ResponseError(err.message, err.code), pending.src, pending.dst
+			);
 		}
 		this._pendingRequests.clear();
 		this._forwardedRequests.clear();