Memfs throwing an error after update to version 3

[pjotrsavitski]

Describe the bug

Mocking filesystem with memfs as described here throws an error with version 3.

This is what I got using the example code:

Instead change the require of ...../node_modules/tslib/tslib.es6.mjs to a dynamic import() which is available in all CommonJS modules.
Error [ERR_REQUIRE_ESM]: require() of ES Module ...../node_modules/tslib/tslib.es6.mjs not supported.
Instead change the require of ...../node_modules/tslib/tslib.es6.mjs to a dynamic import() which is available in all CommonJS modules.
    at Object.<anonymous> (...../node_modules/tree-dump/lib/index.js:3:17)

Reproduction

Vitest 3 with code from example

System Info

System:
    OS: macOS 15.2
    CPU: (12) arm64 Apple M2 Max
    Memory: 1.36 GB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.18.0 - /usr/local/bin/node
    npm: 10.9.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 131.0.6778.265
    Edge: 131.0.2903.147
    Safari: 18.2
  npmPackages:
    @vitejs/plugin-react: ^4.3.2 => 4.3.4 
    @vitest/coverage-v8: ^3.0.0 => 3.0.0 
    vite: ^6.0.7 => 6.0.7 
    vitest: ^3.0.0 => 3.0.0

Used Package Manager

npm

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[boldurean]

Same happens when using Mui with @emotion styles

[vladkrasn]

I had similar errors with some other package on Node v22.6 and after updating to v22.13 they disappeared

[sandhose]

I'm also experiencing this, with Vitest 3, but only with Vite 6. Downgrading Vite to 5 (but keeping Vitest at version 3) 'fixes' it, so I suspect it is because of something which changed in Vite 6

[tsirlucas]

Same happens when using Mui with @emotion styles

same issue. fixed by updating node to 22.13.

It works fine on 3.0.0-beta.4.

[Primajin]

I can confirm updating node from 21 to 22 the error disappeared. However this feels a bit like slapping flex tape on a leaking water tank to me 🤔

Primajin/satellite-tracker@7927a2f

[pjotrsavitski]

As @sandhose mentioned the problem arises with Vitest version 3 and Vite version 6. For some reason downgrading to previous version make the issue disappear. It seems strange as the tree-dump is still there as a dependency of the memfs.

Forgot to mention that there is another issue with the example code as readHelloWorld would return a buffer and test would compare that buffer with texts. The function body would either need to be changed to readFileSync(path, { encoding: 'utf8', flag: 'r' }) to return string or the test would need to be modified to call .toString() each time the buffer value is compared to a text. The first solution seems to be more reasonable.