From a0a69ee146b39b9ee80dffaaa9ad79cf87f7dff8 Mon Sep 17 00:00:00 2001
From: Felipe Cardozo <fraifelipe@gmail.com>
Date: Mon, 27 Oct 2025 22:31:33 -0300
Subject: [PATCH] fix: body already used error to throw TypeError (#24114)

Should fix https://github.com/oven-sh/bun/issues/24104

### What does this PR do?

This PR is changing `ERR_BODY_ALREADY_USED` to be TypeError instead of
Error.


### How did you verify your code works?
A test case added to verify that request call correctly throws a
TypeError after another request call on the same Request, confirming the
fix addresses the issue.

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
---
 src/bun.js/bindings/ErrorCode.ts            |  2 +-
 test/js/web/fetch/body-mixin-errors.test.ts | 25 +++++++++++++--------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/bun.js/bindings/ErrorCode.ts b/src/bun.js/bindings/ErrorCode.ts
index 31a3c28bac..e87e171e6e 100644
--- a/src/bun.js/bindings/ErrorCode.ts
+++ b/src/bun.js/bindings/ErrorCode.ts
@@ -20,7 +20,7 @@ const errors: ErrorCodeMapping = [
   ["ERR_ASSERTION", Error],
   ["ERR_ASYNC_CALLBACK", TypeError],
   ["ERR_ASYNC_TYPE", TypeError],
-  ["ERR_BODY_ALREADY_USED", Error],
+  ["ERR_BODY_ALREADY_USED", TypeError],
   ["ERR_BORINGSSL", Error],
   ["ERR_ZSTD", Error],
   ["ERR_BROTLI_INVALID_PARAM", RangeError],
diff --git a/test/js/web/fetch/body-mixin-errors.test.ts b/test/js/web/fetch/body-mixin-errors.test.ts
index b7568e4dc4..5fce3d4a6c 100644
--- a/test/js/web/fetch/body-mixin-errors.test.ts
+++ b/test/js/web/fetch/body-mixin-errors.test.ts
@@ -1,17 +1,24 @@
 import { describe, expect, it } from "bun:test";
 
 describe("body-mixin-errors", () => {
-  it("should fail when bodyUsed", async () => {
-    var res = new Response("a");
-    expect(res.bodyUsed).toBe(false);
-    await res.text();
-    expect(res.bodyUsed).toBe(true);
+  it.concurrent.each([
+    ["Response", () => new Response("a"), (b: Response | Request) => b.text()],
+    [
+      "Request",
+      () => new Request("https://example.com", { body: "{}", method: "POST" }),
+      (b: Response | Request) => b.json(),
+    ],
+  ])("should throw TypeError when body already used on %s", async (type, createBody, secondCall) => {
+    const body = createBody();
+    await body.text();
 
     try {
-      await res.text();
-      throw new Error("should not get here");
-    } catch (e: any) {
-      expect(e.message).toBe("Body already used");
+      await secondCall(body);
+      expect.unreachable("body is already used");
+    } catch (err: any) {
+      expect(err.name).toBe("TypeError");
+      expect(err.message).toBe("Body already used");
+      expect(err instanceof TypeError).toBe(true);
     }
   });
 });