use listen instead of connect to find free port

lib/get-free-port.js

@@ -1,32 +1,34 @@
-const { Socket } = require('net');
+const { Server } = require('net');
 
-// This works by trying to connect to a port.
-// If connecting works then the port is in use
-// If not the port is free
+// This works by trying to listen on a port.
+// If connecting works then the port is good to use.
+// If not the port is busy, try another
 async function getFreePort(port) {
   return new Promise((resolve, reject) => {
-    const socket = new Socket();
-    const timeout = () => {
-      resolve(port);
-      socket.destroy();
-    };
+    const server = new Server();
+//    const timeout = () => {
+//      resolve(port);
+//      socket.destroy();
+//    };
 
     const next = () => {
-      socket.destroy();
+      server.close();
       resolve(getFreePort(++port));
     };
 
-    setTimeout(timeout, 10);
-    socket.on("timeout", timeout);
-    socket.on("connect", () => next());
-    socket.on("error", error => {
-      if (error.code !== "ECONNREFUSED")
-        reject(error);
-      else
-        resolve(port);
+//    setTimeout(timeout, 1000);
+//    server.on("timeout", timeout);
+    server.on("listening", () => {
+      server.close();
+      resolve(port);
     });
+    server.on("error", next);
 
-    socket.connect(port, "0.0.0.0");
+    server.listen({
+      port, 
+      host: "0.0.0.0",
+      exclusive: true,
+    });
   });
 };