Copyright 2017 Dave Gurnell.

Slides for a talk at Async on 7th September 2017.

Getting into the Flow: Static Types for Javascript by Dave Gurnell is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Static type systems are all the rage these days. Languages like Typescript, Elm, and Purescript, use static types to reason about code without running it, eliminating certain classes of bugs and making code easier to understand.

However, adopting a new programming language comes at a cost. Wouldn't it be nice if we could benefit from static types in our existing Javascript code without jumping over to a new language?

Enter Facebook's Flow, a static type checker for ordinary Javascript. In this talk I'll show you how to add Flow to an existing Javascript project. I'll demonstrate how Flow's static types work and how they'll help uncover bugs in your code. Finally, I'll talk about how to adjust your programming style to get the most benefit from static types.

Dave is a Scala developer moonlighting as a Javascripter. By day he works for Brighton-based Scala consultancy Underscore (no relation to the popular Javascript library). He spends most of his time writing software, writing books about writing software, and building synthesizers from the souls of tormented cats.