@stylexswc/plugin-shared

Shared core for @stylexswc/webpack-plugin and @stylexswc/rspack-plugin.

[!NOTE] This is an internal package. Use one of the bundler plugins above instead of depending on it directly; its API may change between minor releases.

What lives here

• StyleXPluginCore — bundler-agnostic plugin logic: option normalization, StyleX rule bookkeeping, the Next.js App Router cross-compiler registry, and final CSS generation (processStylexRules + transformCss + asset replacement).
• stylex-loader — runs the @stylexswc/rs-compiler Rust transform on JS/TS modules, stores extracted rules on module.buildInfo (webpack transport), and appends a context-relative dummy CSS import carrying the rules in its query (rspack transport + HMR invalidation).
• stylex-virtual-css-loader — stamps a content-hashed dummy rule in development so style edits invalidate HMR; passes through in production.
• stylex.css — the carrier stylesheet consumers import once at their app entrypoint; the plugin replaces the emitted asset content with the extracted StyleX CSS.
• stylex-virtual.css — the physical target of the per-module dummy imports.
• Shared constants, option types, and utilities used by both wrapper plugins.

Rule transports

The two bundlers move extracted rules from the loader to the plugin differently:

• webpack: the loader writes rules to module.buildInfo; the plugin collects them in compilation.hooks.finishModules. buildInfo is persisted in webpack's filesystem cache, so cached rebuilds (where loaders don't re-run) keep their CSS.
• rspack: loaders can't persist module.buildInfo across the native boundary, so the plugin re-parses rules from the dummy-import queries embedded in chunk module identifiers on every compilation. Identifiers survive caching and rebuilding the map drops rules of deleted files.

All paths embedded in module identifiers (the from query parameter and the contextified dummy request) are relative to compiler.context, keeping chunk hashes machine-independent across CI runners.

Acknowledgments

This package was inspired by stylex-webpack.