unfortunately following the install instructions does not work under MacOS Mojave.
ref@1.3.5 install /usr/local/lib/node_modules/homebridge-computer-sleep/node_modules/ref
node-gyp rebuild
gyp ERR! configure error
gyp ERR! stack Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/homebridge-computer-sleep/node_modules/ref/build'
gyp ERR! System Darwin 18.2.0
gyp ERR! command "/usr/local/bin/node" "/usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /usr/local/lib/node_modules/homebridge-computer-sleep/node_modules/ref
gyp ERR! node -v v10.14.0
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! ref@1.3.5 install: node-gyp rebuild
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the ref@1.3.5 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/nick/.npm/_logs/2018-11-30T02_21_30_942Z-debug.log`
unfortunately following the install instructions does not work under MacOS Mojave.