node:net: let server.unref() release a Windows named-pipe listener

src/runtime/socket/Listener.rs

@@ -1891,6 +1891,15 @@ impl WindowsNamedPipeListeningContext {
         // return error.FailedChmodPipe;
         //}
 
+        // `uv_listen` made the pipe an active+ref'd uv handle. Strip libuv's
+        // loop ref so the owning `Listener`'s `poll_ref` is the only thing
+        // keeping the process alive (the contract usockets' libuv backend
+        // applies to its handles); otherwise `server.unref()` drops the
+        // `poll_ref` but the uv handle still pins `uv_loop_alive` and the
+        // process never exits.
+        // SAFETY: `this` is live; `&mut uv_pipe` is scoped to this call.
+        unsafe { (*this).uv_pipe.unref() };
+
         let (this, _) = scopeguard::ScopeGuard::into_inner(cleanup);
         Ok(this)
     }

test/js/node/net/node-net-server.test.ts

@@ -1,5 +1,5 @@
 import { realpathSync } from "fs";
-import { bunEnv, bunExe } from "harness";
+import { bunEnv, bunExe, tempDir } from "harness";
 import { AddressInfo, createServer, Server, Socket } from "net";
 import { createTest } from "node-harness";
 import { once } from "node:events";
@@ -629,3 +629,36 @@ describe("accepted socket event-loop hold matches Node (per-connection KeepAlive
     ).toEqual({ stdout: "fast", exitCode: 0, failureDetail: "" });
   });
 });
+
+// The Windows named-pipe listener never stripped libuv's own loop ref from its
+// uv_pipe_t (uv_listen marks the handle active+ref'd), so server.unref()
+// dropped the Listener's KeepAlive but the uv handle still pinned
+// uv_loop_alive and the process never exited. TCP and unix-socket listeners go
+// through usockets, which unrefs its uv handles up front.
+it("server.unref() on a pipe/unix-socket listener lets the process exit", async () => {
+  // The child exits without close() (natural exit is the observable), so the
+  // unix socket file must live in a tempDir the parent disposes.
+  using dir = tempDir("server-unref", {});
+  const listenPath =
+    process.platform === "win32"
+      ? "\\\\.\\pipe\\bun-server-unref-" + process.pid + "-" + Math.random().toString(36).slice(2)
+      : join(String(dir), "server-unref.sock");
+  await using proc = Bun.spawn({
+    cmd: [
+      bunExe(),
+      "-e",
+      `
+      const server = require("net").createServer();
+      server.listen(process.env.SERVER_UNREF_LISTEN_PATH, () => server.unref());
+      setTimeout(() => { process.stdout.write("HUNG"); process.exit(1); }, 4000).unref();
+      `,
+    ],
+    env: { ...bunEnv, SERVER_UNREF_LISTEN_PATH: listenPath },
+    stdout: "pipe",
+    stderr: "pipe",
+  });
+  const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+  expect(stdout).toBe("");
+  expect(exitCode === 0 ? "" : stderr).toBe("");
+  expect(exitCode).toBe(0);
+});