Error: EMFILE: too many open files

[Ten666u]

Current behavior

When using plugin on macOS, the following error occurs after a dev build, in projects with many files:

No typescript errors found.
node:internal/errors:563
    ErrorCaptureStackTrace(err);
    ^

Error: EMFILE: too many open files, watch
    at FSWatcher._handle.onchange (node:internal/fs/watchers:207:21)
Emitted 'error' event on FSWatcher instance at:
    at FSWatcher._handleError (/path/to/project/node_modules/chokidar/index.js:539:18)
    at NodeFsHandler._boundHandleError (/path/to/project/node_modules/chokidar/handler.js:300:49)
    at /path/to/project/node_modules/chokidar/handler.js:149:9
    at foreach (/path/to/projectnode_modules/chokidar/handler.js:81:9)
    at fsWatchBroadcast (/path/to/project/node_modules/chokidar/handler.js:148:5)
    at FSWatcher.<anonymous> (/path/to/project/node_modules/chokidar/handler.js:196:17)
    at FSWatcher.emit (node:events:518:28)
    at FSWatcher._handle.onchange (node:internal/fs/watchers:213:12) {
  errno: -24,
  syscall: 'watch',
  code: 'EMFILE',
  filename: null
}

Node.js v20.11.0

This error seems to be related to the chokidar file watcher used internally, likely due to hitting macOS restrictions on open file descriptors.

🔎 Note: The output (build) directory and node_modules are excluded from the TypeScript and Webpack configs

Expected behavior

There should be no EMFILE: too many open files error during plugin execution on macOS.

Steps to reproduce the issue

1. Use the plugin in a project where a directory contains a large number of files.
2. Start the dev server on macOS.

Environment

• fork-ts-checker-webpack-plugin: ^9.0.2
• typescript: ^5.6.2
• eslint: ^9.9.1
• webpack: 5.94.0
• os: macOS Sohoma 14.5 (23F79)

[MattIPv4]

👋 I'm also running into this, but specifically only after updating to fork-ts-checker-webpack-plugin@9.1.0. If I roll back to fork-ts-checker-webpack-plugin@9.0.3, it does not crash.

Looking at v9.0.3...v9.1.0 leads me to suspect 147aa11 is the cause? I see paulmillr/chokidar#1369, which discusses EMFILE issues in v4.

[fslzrr]

Same here! rolling back to fork-ts-checker-webpack-plugin@9.0.3 solves the issue

[Ten666u]

Thanks @MattIPv4 for the solution! 🙌
Should we close this issue now or wait for maintainers to review/merge your PR first?

[MattIPv4]

I don't have a PR to fix the issue -- I'm not sure what the best fix would be, perhaps using graceful-fs, but I leave that to the maintainers.

[MattIPv4]

Fwiw, there are two watchOptions Webpack settings that also seem to be a workaround for this as also suggested in the upstream chokidar issue (though I do not consider them a fix given this is a clear regression between 9.0.3 and 9.1.0):

  watchOptions: {
    ignored: /node_modules/,
  },

  watchOptions: {
    poll: 1000,
  },

[johaven]

+1