Best practices in library design

John Resig presented some very interesting thoughts on a JavaScript library design based on his experiences with jQuery and FUEL.

John advises how to write a solid API (those ideas seem to be useful not only for JavaScript developers):

• perform universal actions (like CRUD)


• fear adding methods (defer to extensibility, less but more powerful methods)


• constantly review and remove unused code


• provide an upgrade path for deprecated APIs (plugins / extensions supporting obsolete methods)


• reduce to a common root (by finding common usage patterns)


• care about consistency (naming, arguments order)

Here is the presentation video:



Presentation slides are also available at SlideShare: