2 files changed, 38 insertions, 1 deletions

diff --git a/src/js/node/http.ts b/src/js/node/http.ts
index a745f9b32..c8fbf20d6 100644
--- a/src/js/node/http.ts
+++ b/src/js/node/http.ts
@@ -991,7 +991,10 @@ export class ServerResponse extends Writable {
   #finished = false;
 
   // Express "compress" package uses this
-  _implicitHeader() {}
+  _implicitHeader() {
+    const statusMessage = this.statusMessage ?? STATUS_CODES[this.statusCode];
+    this.writeHead(this.statusCode, statusMessage, {});
+  }
 
   _write(chunk, encoding, callback) {
     if (!this.#firstWrite && !this.headersSent) {
@@ -1058,6 +1061,7 @@ export class ServerResponse extends Writable {
       var data = this.#firstWrite || "";
       this.#firstWrite = undefined;
       this.#finished = true;
+      this._implicitHeader();
       this._reply(
         new Response(data, {
           headers: this.#headers,
diff --git a/test/js/node/http/node-http.test.ts b/test/js/node/http/node-http.test.ts
index 3e7da9d34..167cb9883 100644
--- a/test/js/node/http/node-http.test.ts
+++ b/test/js/node/http/node-http.test.ts
@@ -146,6 +146,29 @@ describe("node:http", () => {
             res.end("Path correct!\n");
             return;
           }
+          if (reqUrl.pathname === "/customWriteHead") {
+            function createWriteHead(prevWriteHead, listener) {
+              let fired = false;
+              return function writeHead() {
+                if (!fired) {
+                  fired = true;
+                  listener.call(this);
+                }
+                return prevWriteHead.apply(this, arguments);
+              };
+            }
+
+            function addPoweredBy() {
+              if (!this.getHeader("X-Powered-By")) {
+                this.setHeader("X-Powered-By", "Bun");
+              }
+            }
+
+            res.writeHead = createWriteHead(res.writeHead, addPoweredBy);
+            res.setHeader("Content-Type", "text/plain");
+            res.end("Hello World");
+            return;
+          }
         }
 
         res.writeHead(200, { "Content-Type": "text/plain" });
@@ -507,6 +530,16 @@ describe("node:http", () => {
         req.end();
       });
     });
+    it("re-implemented writeHead, issue#3585", done => {
+      runTest(done, (server, serverPort, done) => {
+        const req = request(`http://localhost:${serverPort}/customWriteHead`, res => {
+          expect(res.headers["content-type"]).toBe("text/plain");
+          expect(res.headers["x-powered-by"]).toBe("Bun");
+          done();
+        });
+        req.end();
+      });
+    });
   });
 
   describe("signal", () => {