fix iterating stack trace (#3600)

* `i + 1` and remove `defer`

* a test

* fix test

2 files changed, 23 insertions, 0 deletions

diff --git a/test/js/bun/http/error-response.js b/test/js/bun/http/error-response.js
new file mode 100644
index 000000000..3284c146b
--- /dev/null
+++ b/test/js/bun/http/error-response.js
@@ -0,0 +1,8 @@
+const s = Bun.serve({
+  fetch(req, res) {
+    s.stop(true);
+    throw new Error("1");
+  },
+  port: 0,
+});
+fetch(`http://${s.hostname}:${s.port}`).then(res => console.log(res.status));
diff --git a/test/js/bun/http/serve.test.ts b/test/js/bun/http/serve.test.ts
index 7182ba68d..bba35c085 100644
--- a/test/js/bun/http/serve.test.ts
+++ b/test/js/bun/http/serve.test.ts
@@ -2,8 +2,10 @@ import { file, gc, Serve, serve, Server } from "bun";
 import { afterEach, describe, it, expect, afterAll } from "bun:test";
 import { readFileSync, writeFileSync } from "fs";
 import { resolve } from "path";
+import { bunExe, bunEnv } from "harness";
 import { renderToReadableStream } from "react-dom/server";
 import app_jsx from "./app.jsx";
+import { spawn } from "child_process";
 
 type Handler = (req: Request) => Response;
 afterEach(() => gc(true));
@@ -980,6 +982,19 @@ describe("should support Content-Range with Bun.file()", () => {
   }
 });
 
+it("formats error responses correctly", async () => {
+  const c = spawn(bunExe(), ["./error-response.js"], { cwd: import.meta.dir, env: bunEnv });
+
+  var output = "";
+  c.stderr.on("data", chunk => {
+    output += chunk.toString();
+  });
+  c.stderr.on("end", () => {
+    expect(output).toContain('throw new Error("1");');
+    c.kill();
+  });
+});
+
 it("request body and signal life cycle", async () => {
   {
     const headers = {