fix: properly clear timeout on connection failure

Related: #3720

lib/client.ts

@@ -113,15 +113,16 @@ export class Client {
    * @private
    */
   private doConnect(name: string, auth: object) {
-    if (this.connectTimeout) {
-      clearTimeout(this.connectTimeout);
-      this.connectTimeout = undefined;
-    }
     const nsp = this.server.of(name);
 
     const socket = nsp._add(this, auth, () => {
       this.sockets.set(socket.id, socket);
       this.nsps.set(nsp.name, socket);
+
+      if (this.connectTimeout) {
+        clearTimeout(this.connectTimeout);
+        this.connectTimeout = undefined;
+      }
     });
   }
 
@@ -277,5 +278,10 @@ export class Client {
     this.conn.removeListener("close", this.onclose);
     // @ts-ignore
     this.decoder.removeListener("decoded", this.ondecoded);
+
+    if (this.connectTimeout) {
+      clearTimeout(this.connectTimeout);
+      this.connectTimeout = undefined;
+    }
   }
 }

test/socket.io.ts

@@ -774,6 +774,29 @@ describe("socket.io", () => {
       });
     });
 
+    it("should close a client without namespace", (done) => {
+      const srv = createServer();
+      const sio = new Server(srv, {
+        connectTimeout: 100,
+      });
+
+      sio.use((_, next) => {
+        next(new Error("nope"));
+      });
+
+      srv.listen(() => {
+        const socket = client(srv);
+
+        const success = () => {
+          socket.close();
+          sio.close();
+          done();
+        };
+
+        socket.on("disconnect", success);
+      });
+    });
+
     describe("dynamic namespaces", () => {
       it("should allow connections to dynamic namespaces with a regex", (done) => {
         const srv = createServer();