swc-plugin-tachys

SWC-based JSX compiler for Tachys. Produces the same compiled output as babel-plugin-tachys, but parses via @swc/core so SWC-based toolchains (Vite, Next.js, Bun) can use the Tachys fast path without bringing in Babel.

This is a plain async transform(source) function, not a real SWC Rust/WASM plugin. Pair it with whatever transform pipeline your bundler exposes.

Install

pnpm add -D swc-plugin-tachys

Requires @swc/core ^1.9.0 as a peer.

Usage

import { transform } from "swc-plugin-tachys"

const { code, compiled } = await transform(source, { filename: "App.tsx" })
// `compiled` = number of function declarations rewritten into markCompiled form.

filename is used for diagnostics and to pick the parser (.ts/.tsx go through the TypeScript parser with tsx enabled when appropriate; everything else uses ECMAScript with JSX on).

The plugin only rewrites function declarations whose name starts with an uppercase letter and whose body matches the supported shape. Components that don't compile are left untouched, so adoption is incremental.

What gets compiled

// Input
function Counter({ count }) {
  return <button>{count}</button>
}

// Output (illustrative)
import { markCompiled, _template } from "tachys/compiled"
const _tpl$Counter_0 = _template("<button></button>")
const Counter = markCompiled(/* mount */, /* patch */, /* compare */)

The runtime then clones the template and runs the generated patch function on prop changes, with no diffing.

License

Dual-licensed under MIT or Apache-2.0, at your option.