npm install: WARN on dependency

The flag -s / --silent works great if you want to remove all warnings and errors:

npm install --silent

npm docs

Are you running on Windows or Linux? If so, fsevents cannot be installed, as it is an OSX-only package.

If you run npm with --loglevel=error, you should no longer see this or any other warnings. As far as I know, there is no way to selectively suppress warnings in npm.