When working with the github OpenUI5 repo's grunt build tools I enjoy the "watch" feature which allows one to make changes to JavaScript or Less files (in src mode) and see them in action after a simple browser refresh.
I see how "load-grunt-config" is used to split up configuration into separate files in the grunt/config folder. In that folder there is a watch.js file which defines the files to watch, separated by "styles" and "js".
When I looked more into the grunt-contrib-watch module it seems that it not only needs the files to watch, but also a "tasks" array which defines the action to take.
But the "tasks" array seems to be missing from grunt/config/watch.js.
So, how does the watch functionality know what to do (such as invoking lessc) when a file changes? Is there a mapping somewhere that matches the "styles" and "js" objects to particular tasks?