Slides: http://blog.lassus.se/files/how_assumption_met_a_magic_hat_jsconfeu.pdf Is it possible to make our programs more robust, easier to reason about and more enjoyable to write by carefully restricting our usage of the JavaScript language? You'll hear the story of when assumption met a magic hat. We'll get to know our heroes Assert and restrict mode, and if time permits we'll pay a short visit to JSShaper - the world they live in. Let the journey begin. For reuse of this video under a more permissive license please get in touch with us. The speakers retain the copyright for their performances.