Node.js 25: localStorage.getItem is not a function in MSW

[qjatjs123123]

Prerequisites

• I confirm my issue is not in the opened issues
• I confirm the Frequently Asked Questions didn't contain the answer to my issue

Environment check

• I'm using the latest msw version
• I'm using Node.js version 20 or higher

Node.js version

v25.1.0

Reproduction repository

https://github.com/qjatjs123123/reproduction-msw-localStorage-bug

Reproduction steps

• error test

clone repo

npm install

nvm use 25.1.0

npm run dev

• success test

clone repo

npm install

nvm use 18.18.2

npm run dev

It seems that the issue reported in #2612
is still unresolved.

Current behavior

unhandledRejection:  TypeError: localStorage.getItem is not a function
    at eval (webpack-internal:///(rsc)/./mocks/server.ts:6:61)
    at <unknown> (rsc)/./mocks/server.ts (C:\Users\Hong\Desktop\study\reproduction-msw-localStorage-bug\.next\server\_rsc_mocks_server_ts.js:20:1)
    at async eval (app\layout.tsx:7:24)

Expected behavior

Should not use localStorage on Node.js 25

[rithik56]

@qjatjs123123 I would like to work on this issue

[himself65]

In Node.js 25.2.0. It will throws an error

Upstream: nodejs/node#60351

[jnoordsij]

For reference: this can already be "circumvented" in two different ways by passing NodeJS flags:

• passing --localstorage-file=<some-file> to ensure the localStorage API can be used properly
• passing --no-experimental-webstorage to ensure the (experimental) API implementation is disabled entirely

[qjatjs123123]

Thanks for pointing out the workarounds!

[kettanaito]

Released: v2.12.4 🎉

This has been released in v2.12.4.

• 📄 Release notes
• 📦 View on npm

Get these changes by running the following command:

npm i msw@latest

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