Top 5 typechecking open source projects

A JavaScript checker and optimizer.

Webpack support for validating TypeScript definitions at runtime.

A python 3 library providing functions and decorators to automatically generate class code, such as constructor body or properties getters/setters along with optional support of validation contracts on the generated setters. Its objective is to reduce the amount of copy/paste code in your classes - and hence to help reducing human mistakes :).

Decorator which checks whether the function is called with the correct type of parameters.

A webpack plugin allowing to call Flow type checker.