fix(node): add http.Server.unref() (#19201)

Closes https://github.com/denoland/deno/issues/19113

cli/tests/unit_node/http_test.ts

@@ -12,6 +12,7 @@ import { deferred } from "../../../test_util/std/async/deferred.ts";
 import { gzip } from "node:zlib";
 import { Buffer } from "node:buffer";
 import { serve } from "../../../test_util/std/http/server.ts";
+import { execCode } from "../unit/test_util.ts";
 
 Deno.test("[node/http listen]", async () => {
   {
@@ -461,3 +462,21 @@ Deno.test("[node/http] ServerResponse _implicitHeader", async () => {
 
   await d;
 });
+
+Deno.test("[node/http] server unref", async () => {
+  const [statusCode, _output] = await execCode(`
+  import http from "node:http";
+  const server = http.createServer((_req, res) => {
+    res.statusCode = status;
+    res.end("");
+  });
+  
+  // This should let the program to exit without waiting for the 
+  // server to close.
+  server.unref();
+  
+  server.listen(async () => {
+  });
+  `);
+  assertEquals(statusCode, 0);
+});

ext/node/polyfills/http.ts

@@ -1500,6 +1500,8 @@ class ServerImpl extends EventEmitter {
 
   #addr: Deno.NetAddr;
   #hasClosed = false;
+  #server: Deno.Server;
+  #unref = false;
   #ac?: AbortController;
   #servePromise: Deferred<void>;
   listening = false;
@@ -1566,7 +1568,7 @@ class ServerImpl extends EventEmitter {
       return;
     }
     this.#ac = ac;
-    serve(
+    this.#server = serve(
       {
         handler: handler as Deno.ServeHandler,
         ...this.#addr,
@@ -1577,13 +1579,31 @@ class ServerImpl extends EventEmitter {
           this.emit("listening");
         },
       },
-    ).finished.then(() => this.#servePromise!.resolve());
+    );
+    if (this.#unref) {
+      this.#server.unref();
+    }
+    this.#server.finished.then(() => this.#servePromise!.resolve());
   }
 
   setTimeout() {
     console.error("Not implemented: Server.setTimeout()");
   }
 
+  ref() {
+    if (this.#server) {
+      this.#server.ref();
+    }
+    this.#unref = false;
+  }
+
+  unref() {
+    if (this.#server) {
+      this.#server.unref();
+    }
+    this.#unref = true;
+  }
+
   close(cb?: (err?: Error) => void): this {
     const listening = this.listening;
     this.listening = false;
@@ -1606,6 +1626,7 @@ class ServerImpl extends EventEmitter {
       this.#servePromise!.resolve();
     }
 
+    this.#server = undefined;
     return this;
   }