Cannot test with `node-redis`: No such module ...

[zidokobik]

What versions & operating system are you using?

Wrangler v4.16.1 on Debian 12/WSL

Please provide a link to a minimal reproduction

No response

Describe the Bug

Vitest fails to run test when using node-redis, installed via npm install redis. The workers use redis via the nodejs compatibility flag. Running the worker locally npx wrangler dev does work, only the test is failling.

Simple worker example: src/index.ts:

import { createClient } from "redis";

export default {
	async fetch(request, env, ctx): Promise<Response> {

		const redis = await createClient({
			socket: {
				host: env.REDIS_HOST,
				port: Number(env.REDIS_PORT),
				tls: true
			},
			username: env.REDIS_USERNAME,
			password: env.REDIS_PASSWORD
		}).connect();
		const result = await redis.ping()  // should returns "PONG"
		return new Response(result);
	},
} satisfies ExportedHandler<Env>;

wrangler.jsonc

{
	"$schema": "node_modules/wrangler/config-schema.json",
	"name": "hello-world",
	"main": "src/index.ts",
	"compatibility_date": "2025-05-25",
	"compatibility_flags": ["nodejs_compat"],
	"observability": {
		"enabled": true
	}
}

tests/index.spec.ts

import { SELF } from 'cloudflare:test';
import { describe, it, expect } from 'vitest';

describe('Hello World worker', () => {
	it("test root", async () => {
		const response = await SELF.fetch('https://example.com');
		expect(await response.text()).toBe('PONG');
	})
});

Please provide any relevant error logs

When running npm test:

> [email protected] test
> vitest


 DEV  v3.0.9 /home/caong/test

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 "2025-05-08",
but you've requested "2025-05-25". Falling back to "2025-05-08"...
workerd/server/server.c++:3251: error: Fallback service failed to fetch module; exception = (unknown):-1: failed: std::exception: Uncaught JsExceptionThrown
stack: /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@27204c3 /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@1a716fa /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@1a4243b /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@272a198 /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@1cc9801 /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@212c9ed /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@1cd8517 /home/caong/test/node_modules/@cloudflare/workerd-linux-64/bin/workerd@29f400c; spec = /?specifier=%2Fhome%2Fcaong%2Ftest%2Fnode_modules%2F%40redis%2Fclient%2Fdist%2Fpackage.json&referrer=%2Fhome%2Fcaong%2Ftest%2Fnode_modules%2F%40redis%2Fclient%2Fdist%2Flib%2Fclient%2Findex.js%3Fmf_vitest_no_cjs_esm_shim&rawSpecifier=..%2F..%2Fpackage.json
 ❯ test/index.spec.ts (0 test)

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

 FAIL  test/index.spec.ts [ test/index.spec.ts ]
Error: No such module "home/caong/test/node_modules/@redis/client/dist/package.json".
 ❯ home/caong/test/node_modules/@redis/client/dist/lib/client/index.js?mf_vitest_no_cjs_esm_shim:24:24
 ❯ home/caong/test/node_modules/@redis/client/dist/index.js?mf_vitest_no_cjs_esm_shim:28:34
 ❯ home/caong/test/node_modules/redis/dist/index.js?mf_vitest_no_cjs_esm_shim:21:18

[CarmenPopoviciu]

This is possibly an issue with unenv polyfills not being passed down correctly to vitest. I think @petebacondarwin is currently looking into this. Will add to our backlog

[GregBrimble]

Related to #7324 maybe?