WebStorm uses 100% CPU
For people that aren't already, make sure you aren't indexing your dist or www folders.
Right click the folder -> "Mark Directory As" -> "Excluded".
Saved me!
What does the indexing do? Can I trun it off?
The index process creates a database of your code, enabling fast searches, code completion, symbol lookup, etc. I don't think you can turn it off, but if you did, WebStorm wouldn't be very useful to you anyway.
This is a well-known issue with WebStorm, but has gotten better with recent versions. See also: https://www.themarketingtechnologist.co/webstorm-10-improves-the-performance-of-indexing-files/