I have a Symfony2 project which uses composer, and I’d like to use this css framework in it : https://github.com/jlong/sass-twitter-bootstrap
Of course, there is no such project on packagist, because this is not a php project. How should I handle this dependency to my project? With composer? If yes, how? Has the package.json file in this project anything to do with composer?
For now, the best way is to not use composer but drop it in the public directory just like you would without composer.
There is a rather old feature ticket for supporting asset-type libraries in composer: https://github.com/composer/composer/issues/524.
You can do what others in the feature ticket suggests and place it in your vendor dir from a zip distribution – but it will make your project structure rather messy.
The package.json in the project is a npm package info file (Node.js package manager).