Installation and setup is identical for Mac, Windows, and Linux. The only requirement is NodeJS which is likely available on your system, but if not, install NVM https://github.com/nvm-sh/nvm.
Install Node
Cloud functions in either Node 6 or 8, so it is recommended that you setup your local env with. For example, with NVM
command line
nvm install 8
nvm use 8
Setup Cloud Functions
command line
npm install firebase-tools -g
firebase login
firebase init functions
cd functions
### Common Issue on Windows
Incorrect environment path on windows https://github.com/firebase/firebase-tools/issues/610