Major additions
New Markdown and accessibility rules: Biome added useTopLevelHeading for Markdown documents and useControlLabel for HTML/JSX controls without accessible labels. It also broadened noSvgWithoutTitle and useExpect to handle boolean aria-hidden and Vitest expect.element() correctly.
Tailwind support expanded across parser, sorter, and linting: Tailwind v4 handling grew significantly with support for container-query and child variants, bare modifiers, variant ties, and custom-property ordering. Biome also added useTailwindShorthandClasses to suggest compact utilities like size-4.
Formatting and parser correctness
HTML formatting became less lossy and more width-aware: Multiple fixes improved how the formatter handles fallback elements, touching text, closing tags in wrap calculations, and meaningful blank lines. These changes reduce surprising whitespace shifts in HTML, Svelte, and Vue output.
CSS parsing and selector formatting were hardened: Comment placement inside functional pseudo selectors is now preserved, bogus declarations recover more gracefully, and Tailwind @variant container-query names are parsed correctly. CSS linting also now accepts math as a generic font name.
Markdown inline HTML modeling was refactored: Inline HTML comments are now tokenized differently, requiring parser, syntax, and formatter updates to better handle edge cases around embedded HTML in Markdown.
Stability, performance, and analysis fixes
Windows ARM64 crash mitigation and promise-analysis speedup: Biome pinned mimalloc back to avoid a Windows ARM64 access-violation crash, and fixed a performance regression in noMisusedPromises/noFloatingPromises when deep type paths are involved.
Several lint false positives and autofix safety issues were corrected: noExtraBooleanCast now preserves grouping in conditional expressions, noComponentHookFactories stops flagging non-function values, embedded Svelte/Vue script exports are shared correctly, and JSX/Astro false positives were reduced.
Other misc changes
- Projects moved into the salsa-backed DB and the embeds crate was renamed to
biome_embeds. - CLI help text and release automation wording were refreshed.
- Dependency bumps, workflow updates, snapshots, and test coverage additions across HTML, CSS, Markdown, Tailwind, and analyzer paths.