fix(ext/node): delay accept() call 2 ticks in net.Server#listen

ext/node/polyfills/internal_binding/tcp_wrap.ts

@@ -45,6 +45,7 @@ import {
   INITIAL_ACCEPT_BACKOFF_DELAY,
   MAX_ACCEPT_BACKOFF_DELAY,
 } from "ext:deno_node/internal_binding/_listen.ts";
+import { nextTick } from "ext:deno_node/_next_tick.ts";
 
 /** The type of TCP socket. */
 enum socketType {
@@ -228,7 +229,14 @@ export class TCP extends ConnectionWrap {
     this.#port = address.port;
 
     this.#listener = listener;
-    this.#accept();
+
+    // TODO(kt3k): Delays the accept() call 2 ticks. Deno.Listener can't be closed
+    // synchronously when accept() is called. By delaying the accept() call,
+    // the user can close the server synchronously in the callback of listen().
+    // This workaround enables `npm:detect-port` to work correctly.
+    // Remove these nextTick calls when the below issue resolved:
+    // https://github.com/denoland/deno/issues/25480
+    nextTick(nextTick, () => this.#accept());
 
     return 0;
   }

tests/unit_node/net_test.ts

@@ -228,3 +228,22 @@ Deno.test("[node/net] BlockList doesn't leak resources", () => {
   blockList.addAddress("1.1.1.1");
   assert(blockList.check("1.1.1.1"));
 });
+
+Deno.test("[node/net] net.Server can listen on the same port immediately after it's closed", async () => {
+  const serverClosed = Promise.withResolvers<void>();
+  const server = net.createServer();
+  server.on("error", (e) => {
+    console.error(e);
+  });
+  server.listen(0, () => {
+    // deno-lint-ignore no-explicit-any
+    const { port } = server.address() as any;
+    server.close();
+    server.listen(port, () => {
+      server.close(() => {
+        serverClosed.resolve();
+      });
+    });
+  });
+  await serverClosed.promise;
+});