ReactAF does for React what Babel does for JavaScript Let’s say for a moment that you are a component developer and you maintain, or are writing an OSS React package. As you don’t control the application itself, a best practice if for you to specify as a in your , something file like this. react peerDependency package.json "peerDependencies": {"react": ">=15.0.0"} What this specifies is that your package relies on versions 15.0.0 and above, but you expect that the dependency be provided for you (meaning the application must include in list of dependencies). Using prevents the unnecessary bloat and confusion of shipping React within your library build. react react its peerDependencies But think about this for a second— Your component what version of React that the consuming application has specified and that your code will be running against. All you can do, from a package perspective, is give a range of acceptable versions. Your code must be able to handle whatever version of React that it is given. has no idea So… If your package wishes to use a React feature that was introduced in React 16.2.0, for example, you’re out of luck if the application is using React 15.4.0. For instance, what if you wanted to use the new context API introduced in React 16.3.0? Sorry (well, only if you wanted to force your users to use 16.3.0). What about the new static ? Same thing. getDerivedStateFromProps As a developer, this presents a bit of a quandary. Either you fill your code with all kinds of or you code to the lowest common denominator. feature detection Wouldn’t it be nice if you could rely on newer React features being there, no matter what version of React is running? Babel does this with the language. When you transpile with Babel, you can code as though the browser supports ES2018 (for example), even though your code may be running on IE10, which was released in 2012. JavaScript Network This is what ReactAF does. How does it work? ReactAF does for React what Babel does for JavaScript. It allows you to code using React features that aren’t available in older versions of React. But how does it work? ReactAF imports React internally. If the version of React already has the features that it emulates, the “real” React is returned. If not, it the missing features and exposes a version of React. polyfills monkey patched How does it work? It’s like magic. API ReactAF provides/emulates the following React APIs on lower version of React. static getDerivedStateFromProps This is a static method on class components that was introduced in React 16.3.0-alpha. It is intended to replace the lifecycle event , which will be deprecated in v17.0. componentWillReceiveProps If you are running v16.3.0 or greater, you will be using the native implementation. Otherwise, this method is polyfilled. More about in by . getDerivedStateFromProps this article Bartosz Szczeciński React.Fragment is that is exposed on the object in v16.2.0 and greater. It is intended as a way to return multiple elements from without the need for a wrapping dummy element. Fragment a new component React render div More information on Fragments can be found on the . official React blog React. createContext is the new context API that has so many people excited. It too was released in React 16.3.0-alpha. createContext You can read more about the new Context API in by . this article Kent C. Dodds And more… Actually, no… that’s all. But as React releases new features, ReactAF will be updated to support them via a polyfill, where possible (PRs welcome 😉). This way you can always code using the latest React APIs in your package, no matter the version that the consuming app is using. Changing your code And here’s the best thing of all. To start using ReactAF, all you need to do is add 3 little characters: . -af Instead of this. import React from 'react'; You would do this. import React from 'react**-af**'; Where do you get it? ReactAF is (of course). You can see the source code and/or contribute on GitHub. I’d love your help making ReactAF even better! available on npm And if you’re feeling generous, a ⭐️ would be appreciated. 🙏 _react-af - Allows you to code using certain React.next features today! Perfect for component library maintainers._github.com donavon/react-af Conclusion While ReactAF may not be for everyone, it can really benefit OSS package developers, giving them the freedom to code using modern React APIs. I’d say that make this package React As F&#%! And please… Forgive any informercial-esque qualities of this post. ¯\_(ツ)_/¯ I also write for the American Express Engineering Blog. Check out my other works and the works of my talented co-workers at AmericanExpress.io . You can also follow me on Twitter .
