Add SWC Plugin

[heygrady]

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 (facebook/create-react-app#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).

[kentcdodds]

Hi @heygrady!

That sounds cool. I don't have the bandwidth to work on it myself, but if you want to do it then you're welcome to! 👍

[c-rick]

try this code, it work for me
next-twin

[conartist6]

What language are SWC plugins written in? Rust?

[conartist6]

Indeed, they are written in Rust. So macros would have to be themselves written in Rust. This may be possible, but it won't share any code or architecture with babel-plugin-macros and would require maintainers with a completely different skill set. I'm going to close this issue as it will never be actionable here. Best of luck to those looking for this functionality.

[renchap]

Some update on the SWC front here: swc-project/swc#3167

TL;DR: they are integrating WASM plugin support in SWC. This means you can write your plugins in any language that can be compiled to WASM, for example Typescript with https://www.assemblyscript.org

Would this make it easier to have a macros plugin for SWC ?

[conartist6]

That might make it possible! May I suggest that you make a repo or chat or something for people who are interested in using or building that functionality to talk and collaborate, and you should link to it here.

[renchap]

The plugin support in SWC is still an experimental work in progress. If it lives up to expectations and goes into a release, then I will see what I can do!

But I suspect that it will need to be a separate project from this one, as SWC uses a different AST than babel, so macros will probably need to be rewritten entirely

[conartist6]

I agree that it would be a separate project that would not be intercompatible with this one. Hence the suggestion to make a new space for interested contributors.

[matthewmatician]

Maybe this is a noob question, but wouldn't this PR have made this possible?

[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.

[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