Major language and formatter expansion
Markdown support landed end-to-end — Biome added a dedicated Markdown analyzer, parser work for frontmatter and deferred inline parsing, formatter performance improvements, and multiple new Markdown lint rules including top-level heading enforcement and consistent heading levels.
YAML parsing got much more robust — The YAML parser gained better error recovery, broader conformance coverage, and benchmark wiring, making YAML a first-class and actively tuned language path.
HTML, Astro, Vue, and Svelte handling improved substantially — The month included many parser/formatter fixes for embedded scripts/styles, interpolation edge cases, comments, blank lines, void elements, and framework-specific syntax. Stdin analysis also gained fuller Astro/Svelte/Vue support when experimental full support is enabled.
CSS and Tailwind got deeper semantic support
Registered custom properties are now understood semantically — Biome added @property parsing, validation, semantic queries, module-graph tracking, and a new lint for invalid initial-value declarations. It also added noUndeclaredCustomProperties and improved CSS analysis around custom property references.
SCSS and CSS parsing/formatting became more capable — Support expanded for partial combinator selectors, interpolated media queries, SCSS url(...) interpolation, bogus declaration recovery, and more stable comment/selector formatting.
Tailwind sorting rules were expanded and refined — The sorter now handles container-query variants, child/descendant variants, bare modifiers, legacy ! syntax, and custom-property ordering more accurately, while also adding a new shorthand-classes lint.
More lint coverage across ecosystems
New safety and accessibility rules landed — Highlights include noExtendNative, noNonScalableViewport, useControlLabel, noAstroSetHtmlDirective, noUnsafeTypeAssertion, useNamedLayer, noInvalidFileInputAccept, and several framework-specific false-positive fixes.
Existing JS/TS rules got smarter and faster — noFloatingPromises, noMisusedPromises, noUndeclaredVariables, noUnusedImports, noUnusedVariables, useStrictMode, and others saw inference fixes, fewer false positives, and performance wins on class-member and dependency-heavy code.
Core architecture, plugins, and performance
Plugin and runtime support expanded — JS plugins can now query AST nodes by kind, TypeScript plugins are supported, and WASM builds can opt into JS plugins. GritQL handling also improved for snippets, exports, and byte offsets.
Internal analysis and storage were refactored — The project moved toward salsa-backed project storage, reworked analyzer settings and deserialization for better sharing and lower code size, and cleaned up legacy type-inference machinery.
Several hot paths got faster — Performance work landed in markdown parsing/formatting, import-cycle detection, promise analysis, rule profiling, workspace scanning, and LSP cache eviction, with multiple benchmark additions to keep regressions visible.
Other misc changes
- CLI/help/documentation wording and daemon logging fixes
- CI, workflow, dependency, and release-tooling updates
- Many test, snapshot, and codegen refreshes across CSS, HTML, JS, Markdown, YAML, Vue, Svelte, and Grit