Facebook has released Flow, a static type checker for JavaScript, under an open source license. According to the social network, “Flow adds static typing to JavaScript to improve developer productivity and code quality. In particular, static typing offers benefits like early error-checking?which helps you avoid certain kinds of runtime failures?and code intelligence, which aids code maintenance, navigation, transformation, and optimization.”
The company added, “Facebook loves JavaScript; it’s fast, it’s expressive, and it runs everywhere, which makes it a great language for building products. At the same time, the lack of static typing often slows developers down. Bugs are hard to find (e.g., crashes are often far away from the root cause), and code maintenance is a nightmare (e.g., refactoring is risky without complete knowledge of dependencies). Flow improves speed and efficiency so developers can be more productive while using JavaScript.”
Flow is available for download through GitHub, and there is also a website with more information at Flowtype.org.