composer-link()

.bash_profile

// Require local folder as Composer dependency 
// whereas _package_ is a unique package ID to keep composer from overwriting existing config
//
// from within the project folder, run the following:
// composer-link /path/to/package package
// Then run composer require as usual.

composer-link() {  
    composer config repositories."$2" '{"type": "path", "url": "'$1'"}' --file composer.json
}