One dark and stormy night I decided to finally learn about JavaScript Proxies. So I started reading and noticed that it was possible to inspect parameters befo

One dark and stormy night I decided to finally learn about JavaScript Proxies. So I started reading and noticed that it was possible to inspect parameters before function execution, and results after function returns; just like Clojure Spec https://news.ycombinator.com/item?id=24432461 https://news.ycombinator.com/item?id=24432461 does. At first I thought that I would be confined to type checking plain JavaScript functions, but I managed to handle constructors and methods inside classes, closures, and IIFEs. Thus TypeCzech was born with an odd but unique searchable name. Why you might want to use: - Type signtures are JavaScript strings, arrays, and objects; thus can be constants - No complilation, no dependencies, no new syntax, easy to decouple - Throw exceptions or just console.log errors More live examples than you can shake a stick at at https://jsfiddle.net/steen_hansen/1Lshcept/?Example-Contents https://jsfiddle.net/steen_hansen/1Lshcept/?Example-Contents