JavaScript Testing and Static Type Systems at Scale – @Scale 2014 – Web

Avik Chaudhuri, Software Engineer at Facebook and Jeff Morrison, Software Engineer at Facebook
To encourage engineers to continue to make changes to the codebase, we spent some time identifying various important traits around automated testing, and used our insights to build a tool (called Jest) that makes it as simple and straightforward as possible for developers to write tests. The code we write must not only exploit the full flexibility and expressiveness offered by the JavaScript language, but also clear an incredibly high bar for robustness, performance, and hackability. At Facebook, we’re working on adding static types to JavaScript without disempowering the dynamism that makes JavaScript great.

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