[Bug] Hot reloading broken when saving a file from a workspace that has peerDependencies listed

[dalinarkholin]

• I'd be willing to implement a fix

Describe the bug

When adding a peerDependency to a workspace that is shared between multiple front end applications(react), our dev cycle is somewhat disrupted. Hot reloading no longer picks up changes to file saves within the shared workspace.

To Reproduce

Reproduction found here

• clone
• cd packages/project
• yarn start
• save file within packages/shared
• note recompile does not occur

Environment if relevant (please complete the following information):

• OS: macOS Catalina
• Node version: 12.16.1
• Yarn version: 2.0.0-rc.31

[dalinarkholin]

The workaround for this issue is to disable polling for the time being until fs.watchFile can work with a Virtual FS.

[missing1984]

I think I ran into the same issue. How do you disable polling in this case?

[ChiefORZ]

i stumbled upon the same issue, and the tip from @dalinarkholin helped as a workaround!
when using chokidar - you can force to use fs.watch by setting the environment variable CHOKIDAR_USEPOLLING=0. this works for create-react-app for example: CHOKIDAR_USEPOLLING=0 yarn dev

thanks for the workaround!

[yarnbot]

Hi! 👋

This issue looks stale, and doesn't feature the reproducible label - which implies that you didn't provide a working reproduction using Sherlock. As a result, it'll be closed in a few days unless a maintainer explicitly vouches for it or you edit your first post to include a formal reproduction (you can use the playground for that).

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[missing1984]

spent some time on this, it turns out to be chokidar and our virtual fs patch on fsevents causes those issues.

It's easy to reproduce:

const chokidar = require('chokidar');

const files = [
    '/foo',
    '/foo/.yarn/$$virtual/foo-virtual-fbd1a43281/3/lib/index.js',
];

chokidar.watch(files).on('change', (event, path) => {
    console.log(event, path);
});

in this case, chokidar only uses fsevents to watches /foo as it's the root. Updating index.js would not trigger the callback which seems to be wrong.

and btw, CHOKIDAR_USEPOLLING=0 no longer works in latest webpack.