Running Jest with yarn pnp enabled and node v20 leaks memory

[yossizahn]

Self-service

• I'd be willing to implement a fix

Describe the bug

The following combination of circumstances causes a memory leak of approx. 200mb per second on my machine:

• yarn with pnp enabled
• node v20
• yarn jest --watch

I don't know if this is a yarn issue or a nodejs issue or a jest issue
I can only reproduce the problem when all the conditions are met (yarn pnp, node 20, jest --watch)

To reproduce

I am not sure how to test for a memory leak using sherlock

I have created minimal reproduction here: https://github.com/yossizahn/yarn-pnp-jest-node20-memleak

Environment

System:
    OS: macOS 13.3.1
    CPU: (8) arm64 Apple M1
  Binaries:
    Node: 20.0.0 - /private/var/folders/6t/cgb4q3vj0tngmc63b3_t3l1h0000gn/T/xfs-66d5c86b/node
    Yarn: 3.5.0 - /private/var/folders/6t/cgb4q3vj0tngmc63b3_t3l1h0000gn/T/xfs-66d5c86b/yarn
    npm: 9.6.4 - ~/.nvm/versions/node/v20.0.0/bin/npm

Additional context

No response

[arcanis]

Probably caused by nodejs/node#47566

[merceyz]

You're running into nodejs/node#47566, if you don't need ESM support you can disable it to avoid the upstream bug.

yarn config set pnpEnableEsmLoader false
yarn install

https://yarnpkg.com/configuration/yarnrc#pnpEnableEsmLoader

[yossizahn]

Thanks!
(I spent hours isolating this bug 😅, I'm happy the cause has been identified already)