Error: No such module "node:os".

[hotrush]

I'm trying to test my worker with miniflare and so adding next code to my index.spec.ts

import { Miniflare } from 'miniflare';

const mf = new Miniflare({
	modules: true,
	scriptPath: './src/index.ts',
	r2Buckets: ['R2_BUCKET'],
});

When running it i'm getting an error:

Using vars defined in .dev.vars
[vpw:inf] Starting isolated runtimes for vitest.config.mts...
[mf:wrn] The latest compatibility date supported by the installed Cloudflare Workers Runtime is "2024-12-05",
but you've requested "2024-12-16". Falling back to "2024-12-05"...
workerd/server/server.c++:3052: error: Fallback service failed to fetch module; payload = ; spec = /?specifier=node%3Aos&referrer=%2FUsers%2Frush%2FProjects%2Fproj%2Fnode_modules%2Fminiflare%2Fdist%2Fsrc%2Findex.js%3Fmf_vitest_no_cjs_esm_shim&rawSpecifier=node%3Aos
 ❯ test/index.spec.ts (0)

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Failed Suites 1 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

 FAIL  test/index.spec.ts [ test/index.spec.ts ]
Error: No such module "node:os".
 ❯ Users/rush/Projects/proj/node_modules/miniflare/dist/src/index.js?mf_vitest_no_cjs_esm_shim:2623:26

Node: v20.17.0
Miniflare: 3.20241205.0

[andyjessop]

@hotrush thanks very much for reporting this! Would you be able to provide us with a minimal reproduction? I can't reproduce this locally, and I'm wondering how this node:os dependency is creeping into the code.

[hotrush]

@andyjessop here it is https://github.com/hotrush/cf-miniflare-eror, just run npm run test.

[emily-shen]

hiya, it looks like you're using the vitest integration as well as creating a miniflare instance yourself? Unless I'm missing something about your setup, you should be able to do this with just vitest (see this on how to use env to perform actions on a resource) which should not have this issue.