`mock.property()`: 'process.env' does not accept an accessor(getter/setter) descriptor

[regseb]

Version

v22.21.0

Platform

Linux regseblaptop4l 6.14.0-34-generic #34-Ubuntu SMP PREEMPT_DYNAMIC Wed Sep 17 09:21:29 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

1. Create index.js:

   import { mock } from "node:test";
   
   console.log(Object.getOwnPropertyDescriptor(process.env, "PATH"));
   
   mock.property(process.env, "PATH", "foo");
   
   console.log(process.env.PATH);

2. node index.js

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

Always.

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

The variable process.env.PATH is mocked by mock.property(object, propertyName[, value]).

{
  value: '/usr/local/sbin:/usr/local/bin:/usr/sbin',
  writable: true,
  enumerable: true,
  configurable: true
}
foo

What do you see instead?

{
  value: '/usr/local/sbin:/usr/local/bin:/usr/sbin',
  writable: true,
  enumerable: true,
  configurable: true
}
node:internal/test_runner/mock/mock:308
    ObjectDefineProperty(object, propertyName, {
    ^

TypeError: 'process.env' does not accept an accessor(getter/setter) descriptor
    at defineProperty (<anonymous>)
    at new MockPropertyContext (node:internal/test_runner/mock/mock:308:5)
    at MockTracker.property (node:internal/test_runner/mock/mock:717:7)
    at file:///home/regseb/testcase/index.js:5:6
    at ModuleJob.run (node:internal/modules/esm/module_job:343:25)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:665:26)
    at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:117:5) {
  code: 'ERR_INVALID_OBJECT_DEFINE_PROPERTY'
}

Node.js v22.21.0

Additional information

Pull request for adding the mock.property() method: #58438

[sakina1303]

can i please work on this! kindly assign it to me.

[marco-ippolito]

can i please work on this! kindly assign it to me.

you can just send a PR, we usually dont assign issues

[sakina1303]

can i please work on this! kindly assign it to me.

you can just send a PR, we usually dont assign issues

Got it, thank you! I’ll start working on it and raise a PR once it’s ready.

[sakina1303]

@marco-ippolito Kindly review the PR when you get a chance. Thank you!

[Renegade334]

Note that this was a deliberate design decision made in #28006. If the motivation for that change still stands, then this is WONTFIX.

The question is whether an accessor property could be considered consistent with the behaviour of conventional process.env properties, if it's a getter/setter pair and is configurable and enumerable. Obviously there's no guarantee that the user-provided accessor will behave as expected.

(cc: @himself65, @addaleax)