Follow these steps to set up your web app developer environment:
To develop for the web app you’re also going to need to set up the developer environment for the server. So if you haven’t done that yet, start there and then come back here.
Install Node.js and npm.
If you’re on Mac, you’ll need to install libpng as well:
brew install libpng
Go to https://github.com/mattermost/mattermost-webapp and fork the repository.
Clone your fork
git clone https://github.com/<yourgithubusername>/mattermost-webapp beside your
mattermost-webapp directory, run
make test. If that passes succesfullly, everything is installed correctly.