Mac OS test watcher failing

[mnemanja]

Is this a bug report?

I believe this is a bug. I'm just not sure who's?

Did you try recovering your dependencies?

I have tried this by using only npm.

Which terms did you search for in User Guide?

Error watching file for changes: EMFILE

Environment

1. node -v: 8.10.0 and 9.9.0
2. npm -v: 5.7.1
3. yarn --version (if you use Yarn):
4. npm ls react-scripts (if you haven’t ejected):

Then, specify:

1. Operating system: Mac OS High Siera
2. Browser and version (if relevant):

Steps to Reproduce

https://github.com/mnemanja/failing-tests-repo

1. Clone repo
2. Install
3. Run tests

From the list of 3 (currently found) problematic dependencies removing one makes the tests watcher work properly:

• node-sass-chokidar: 1.2.2
• material-ui: 0.20.0
• enzyme: 3.3.0

Expected Behavior

Tests should be successfully executed and the watch mode should be active.

Actual Behavior

The watch mode exists and error messages are shown.

Reproducible Demo

https://github.com/mnemanja/failing-tests-repo

I have also created similar reports on all involved repos:
michaelwayman/node-sass-chokidar#50
enzymejs/enzyme#1593
mui/material-ui#10801

I have tried installing the Watchman via brew, as per many suggestions found in this repo and several others, but after the installation, nothing has changed.

[michaelwayman]

This is coming from react-scripts test.js

// Watch unless on CI or in coverage mode
if (!process.env.CI && argv.indexOf('--coverage') < 0) {
  argv.push('--watch');
}

Where the --watch argument is being added to jest.
There are 2 workarounds for now,

1. export CI=true before you run the tests
2. in package.json you can add the coverage flag "test": "react-scripts test --env=jsdom --coverage"

But as of yet I am not sure why the jest watch flag in combination with those packages would break the jest tests..

[mnemanja]

@michaelwayman The point is to have the tests run in the watch mode, which currently doesn't happen.
Exporting CI=true and setting coverage removes not only the error but the watch mode as well.

[adambowles]

What errors are being printed?

Could it be this? nodejs/node#15683
(Solved for me by installing watchman: brew install watchman)

[mnemanja]

That's the error and the watchman didn't fix it.

2017-10-02 11:38 node[63244] (FSEvents.framework) FSEventStreamStart: register_with_server: ERROR: f2d_register_rpc() => (null) (-22)
2017-10-02 11:38 node[63244] (FSEvents.framework) FSEventStreamStart: register_with_server: ERROR: f2d_register_rpc() => (null) (-22)
events.js:182
      throw er; // Unhandled 'error' event
      ^

Error: Error watching file for changes: EMFILE
    at _errnoException (util.js:1021:13)
    at FSEvent.FSWatcher._handle.onchange (fs.js:1369:9)

[yashka713]

@mnemanja brew install watchman solve my problem, but before I had the same Issue.
"test": "react-scripts test --env=jsdom I, also, have this line
Maybe, you should remove
node_modules
yarn.lock
package.json.lock(if present)
And start yarn to recreate dependency?

[gaearon]

This problem was solved in more recent Jest versions, which you can use through our 2.x alpha.
Instructions: #3815

Unfortunately there's no fix coming for the 1.x branch of react-scripts. So your best bet is to either start using 2.x alphas (warning: they're somewhat unstable) or to keep trying different workarounds in the threads you linked to.

[mnemanja]

Thanks,
now it works like a charm :) 👍