macOS Sierra (10.12) unable to run tests

After upgrading to sierra I’ve got the following error being thrown each time I run npm test

Determining test suites to run...

2016-10-30 15:28 node[763] (FSEvents.framework) FSEventStreamStart: register_with_server: ERROR: f2d_register_rpc() => (null) (-22)
2016-10-30 15:28 node[763] (FSEvents.framework) FSEventStreamStart: register_with_server: ERROR: f2d_register_rpc() => (null) (-22)
2016-10-30 15:28 node[763] (FSEvents.framework) FSEventStreamStart: register_with_server: ERROR: f2d_register_rpc() => (null) (-22)
events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: Error watching file for changes: EMFILE
    at exports._errnoException (util.js:1026:11)
    at FSEvent.FSWatcher._handle.onchange (fs.js:1406:11)
npm ERR! Test failed.  See above for more details.

So far unable to find any fixes, anyone?

Environment

Run these commands in the project folder and fill in their results:

1. npm ls react-scripts (if you haven’t ejected): react-scripts@0.6.1
2. node -v: v6.9.1
3. npm -v: 3.10.8

[gaearon]

It would be great if you could spend some time debugging what happens without watchman. Many people had and keep having this issue but nobody helped investigate it so far.

[bondarewicz]

@fson thanks for the tip, unfortunately this does not solve the issue… I found the following link however following also doesn’t fix it 😦

# check open file limit
sysctl kern.maxfiles

# edit sysctl
sudo vim /etc/sysctl.conf

# add these two lines
kern.maxfiles=10485760
kern.maxfilesperproc=1048576

# reboot
sudo reboot

# check new file limit
sysctl kern.maxfiles

EDIT: just found that installing watchman fixes an issue, from https://github.com/facebook/jest/issues/1767