clay / claycli / 39796429394

85%

master: 85%

Pull #277

github

🍕 vite: compile CSS with Lightning CSS across worker threads

The styles step ran autoprefixer and cssnano on the main thread; cssnano was
about two thirds of its time. Keep postcss-import, postcss-mixins,
postcss-simple-vars and postcss-nested, then run Lightning CSS for vendor
prefixes and minification, and compile files across worker threads (one per
core minus one, up to 8; the main thread for small builds and watch
rebuilds). On nymag/sites (2,872 files) `clay vite --only styles` goes from
~17 s to 2.6 s (5.5 s on the main thread), with slightly smaller output.

Lightning CSS targets the project's browserslist (or stylesConfig
`browserslist`). It treats them as the oldest browsers to support: once all
of them support newer syntax it prints that syntax and drops fallbacks. So
autoprefixer's overrideBrowserslist (a usage share like '> 2%', which would
make it print range media queries Safari < 16.4 ignores) is no longer read;
autoprefixerOptions is ignored with a warning.

CSS that Lightning CSS cannot parse is an error at its source file and line.
Every file still compiles and is written, then the styles step fails so
`clay vite` exits non-zero (`--watch` keeps running); files PostCSS cannot
compile fail it too. stylesConfig keeps working (it re-runs in each worker)
and gains `browserslist` and `lightningcssOptions`; `plugins` still run
before Lightning CSS. CLAY-VITE.md documents the options and the CSS
patterns Lightning CSS 1.33 mishandles. clay compile is unchanged.

993 of 1264 branches covered (78.56%)

Branch coverage included in aggregate %.

123 of 140 new or added lines in 3 files covered. (87.86%)

1984 of 2246 relevant lines covered (88.33%)

27.09 hits per line