Add SWC Plugin

https://swc-project.github.io/docs/usage-plugin

Proposal: create an swc-plugin-macros that is similar to babel-plugin-macros

SWC is increasing in popularity. It is aiming to be a drop-in replacement for babel with some significant speed improvements. It already has a webpack loader.

There is some early interest in how it might integrate with create-react-app (https://github.com/facebook/create-react-app/issues/8060). Looking at which babel plugins create-react-app uses it seems like most of those things are supported by swc (with only a few exceptions).

SWC appears to be missing support for:

1. babel-plugin-macros (important for some of my projects)
2. babel-plugin-transform-react-remove-prop-types (less important in TypeScript projects)
3. babel-plugin-transform-flow-strip-types (generally SWC has no Flow support 🤷🏻‍♂️)

Generally everything else babel does for me is handled by swc preset-env (or isn’t particularly vital to my projects).

[arlyon]

I realise this isn’t directly related, however I am working on stailwc, a swc-native version of twin.macro which serves as both

• an example of swc’s macro capabilities
• a neat project (my build times are down ~80% compared to bazel!)
• a living example on how to build a wasm-based swc plugin for nextjs

[conartist6]

@matthewmatician I mean you could always do a two-step process. Parse with babel, transpile macros, send the program to SWC, then have SWC do the rest of the transpilation.

The only question is: how you would send the program to SWC? Obviously you could print it from babel and parse in SWC. But perhaps there’s a more efficient way? I can’t say I understand the PR you linked well enough to know quite what its API would be. If it can do a copy in a way that’s faster than a parse and print, then perhaps the perf numbers would still be favorable at the end of the day.