TypeError: when using fetch in Node but not in Bun

[kevgeoleo]

Version

24.1.0

Platform

Microsoft Windows NT 10.0.26100.0 x64

Subsystem

No response

What steps will reproduce the bug?

Hi,

I encountered an error while running the following code snippet in NodeJs but not in Bun:

Object.prototype.__defineGetter__(0, function () {
  throw 42;
});

const url = "https://example.com";
try {
  const response = await fetch(url);
} catch (error) {
  console.error("Error:", error);
}

The Error:

Error: TypeError: Cannot set property 0 of #<Object> which has only a getter
    at Array.push (<anonymous>)
    at lib/llhttp/constants.js (node:internal/deps/undici/undici:3274:22)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/client-h1.js (node:internal/deps/undici/undici:6327:21)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/client.js (node:internal/deps/undici/undici:8118:21)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/pool.js (node:internal/deps/undici/undici:8567:18)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/agent.js (node:internal/deps/undici/undici:8657:16)
node:internal/async_hooks:541
  execution_async_resources[offset] = resource;
                                    ^

TypeError: Cannot set property 0 of #<Object> which has only a getter
    at pushAsyncContext (node:internal/async_hooks:541:37)
    at emitBeforeScript (node:internal/async_hooks:510:3)
    at process.processTicksAndRejections (node:internal/process/task_queues:80:7)

How often does it reproduce? Is there a required condition?

There is no specific condition

What is the expected behavior? Why is that the expected behavior?

No output

What do you see instead?

Error: TypeError: Cannot set property 0 of #<Object> which has only a getter
    at Array.push (<anonymous>)
    at lib/llhttp/constants.js (node:internal/deps/undici/undici:3274:22)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/client-h1.js (node:internal/deps/undici/undici:6327:21)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/client.js (node:internal/deps/undici/undici:8118:21)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/pool.js (node:internal/deps/undici/undici:8567:18)
    at __require (node:internal/deps/undici/undici:6:50)
    at lib/dispatcher/agent.js (node:internal/deps/undici/undici:8657:16)
node:internal/async_hooks:541
  execution_async_resources[offset] = resource;
                                    ^

TypeError: Cannot set property 0 of #<Object> which has only a getter
    at pushAsyncContext (node:internal/async_hooks:541:37)
    at emitBeforeScript (node:internal/async_hooks:510:3)
    at process.processTicksAndRejections (node:internal/process/task_queues:80:7)

Additional information

No response

[jasnell]

This really has nothing to do with fetch at all, and whether bun throws an error or not is largely irrelevant to Node.js. The issue here is that you're mutating the Object.prototype overriding the 0 indexed property with only a getter and no setter and then a mechanism internal to node.js is trying to set the 0 index on an Array and hitting the fact that you did not define a setter. This really is not a bug in Node.js. You cannot mutate the Object prototype in odd ways without expecting side effects. You'll find that browsers have the same issue:

As does Deno...

The specific error you are seeing is triggered by v8.

Bun also doesn't like the pattern:

Closing the issue as invalid.