Maybe warn if we're inadvertently watching loads of files

[stuartlangridge]

• nodemon -v: 1.17.3
• node -v: v6.9.5
• Operating system/terminal environment: Ubuntu 16.04
• Command you ran: nodemon --exec "node -e 'console.log(2)'"

I had a large folder with (recursively) some tens of thousands of files in it in the current folder, and I wasn't ignoring it (because I'd forgotten that it was there). Nodemon was refusing to restart when I changed a file, and I thought it was broken. After adding a bunch of debug prints to nodemon's lib/monitor/watch.js, it became apparent that it was taking many tens of seconds to add all these files to chokidar's watch, and before that's complete, chokidar doesn't fire change events (and therefore nodemon doesn't get told that a file had changed, and therefore doesn't restart). This is of course not actually nodemon's fault. But perhaps if after a couple of seconds or so, chokidar still isn't finished adding files, maybe nodemon could print a warning ("Warning: not yet monitoring for changes; still scanning files in ./largefolder"), and then print "Now monitoring files" once scanning is complete, or similar?

Since this isn't something that someone would explicitly turn on (if you know you need to turn it on, then you don't need it!), it would need to be something on by default, and that may not be something you want, of course.

[remy]

This used to be in place, but I had a quick scan through the code and I couldn't find it anymore…

[stuartlangridge]

I would have thought that stuartlangridge@0671614 would have worked, but inexplicably it doesn't; the setTimeout never fires, and I don't understand why.

(To replicate, make a folder with loads of files to be monitored in it; I just did for i in $(seq 1 100); do for j in $(seq 1 100); do cp whatever.js hugefolder/file-$i-$j.js; done; done to get 10,000 JS files which nodemon thinks it needs to care about.)

[remy]

I wonder if the CPU blocks during the add, and thus the timeout never gets the chance, then the ready event is fired. Seems odd that it would be synchronous though…

[stale]

This issue has been automatically marked as idle and stale because it hasn't had any recent activity. It will be automtically closed if no further activity occurs. If you think this is wrong, or the problem still persists, just pop a reply in the comments and @remy will (try!) to follow up.
Thank you for contributing <3

[remy]

This turned out to be a perf bug. Simple to replicate, simple to fix. nodemon should have no problem watching 10,000 files - this fix changes it so it can again.