Fix error during slave authentication failure

Treat sending messages over a link that is not connected as a
SessionLost error and handle AuthenticationFailed error in the
startup logic of slave.

lib/link/connectors.js

@@ -97,7 +97,9 @@ class WebSocketBaseConnector extends events.EventEmitter {
 	 * @returns the sequence number of the message sent
 	 */
 	send(type, data) {
-		this._check(["handshake", "connected", "closing"]);
+		if (!["handshake", "connected", "closing"].includes(this._state)) {
+			throw new errors.SessionLost("No session");
+		}
 		let message = { seq: this._seq, type, data };
 		this._sendBuffer.push(message);
 		if (["connected", "closing"].includes(this._state)) {
@@ -271,7 +273,7 @@ class WebSocketClientConnector extends WebSocketBaseConnector {
 			console.log(`SOCKET | Close (code: ${code}, reason: ${reason})`);
 			// Authentication failed
 			if (code === 4003) {
-				this.emit("error", new errors.AuthenticationFailed("Authentication failed"));
+				this.emit("error", new errors.AuthenticationFailed(reason));
 				this._state = "closing";
 			}
 

slave.js

@@ -1275,14 +1275,19 @@ I           version of clusterio.  Expect things to break. I
 `
 	);
 	startSlave().catch(err => {
-		console.error(`
+		if (err instanceof errors.AuthenticationFailed) {
+			console.error(err.message);
+
+		} else {
+			console.error(`
 +--------------------------------------------------------------+
 | Unexpected error occured while starting slave, please report |
 | it to https://github.com/clusterio/factorioClusterio/issues  |
 +--------------------------------------------------------------+`
-		);
+			);
+			console.error(err);
+		}
 
-		console.error(err);
 		process.exit(1);
 	});
 }

test/integration/link.js

@@ -13,7 +13,7 @@ describe("Integration of lib/link", function() {
 		control = new TestControl(controlConnector);
 		await assert.rejects(
 			controlConnector.connect(),
-			new Error("Authentication failed")
+			new Error("Authentication failed: jwt malformed")
 		);
 	});