# Biome 2.5.9 — Biome CLI v2.5.9

- Product: Biome (https://whatsnew.fyi/product/biome)
- Vendor: Biome
- Date: 2026-08-17
- Version: 2.5.9
- Original notes: https://github.com/biomejs/biome/releases/tag/%40biomejs/biome%402.5.9
- Permalink: https://whatsnew.fyi/product/biome/releases/2.5.9

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **fixed** — The CSS parser now recovers at declaration boundaries after bogus declarations, allowing subsequent valid declarations to be parsed
- **changed** — Expanded the environment variable metadata used by biome rage to include BIOME_BINARY, BIOME_LOG_FILE, and RUST_BACKTRACE
- **added** — Added a new nursery rule useNamedLayer which disallows anonymous cascade layers
- **changed** — The HTML formatter now preserves meaningful blank lines in HTML, including spacing after elements with trailing spaces and blank lines between comment groups
- **added** — Added the nursery rule useTailwindShorthandClasses, which suggests shorter Tailwind utility classes
- **fixed** — The lint/nursery/useExpect rule now recognizes Vitest Browser Mode expect.element() calls as assertions
- **fixed** — The CSS parser now accepts Tailwind container-query variant names in @variant, such as @xl and @max-xl
- **fixed** — The noUndeclaredVariables, noUnusedImports, and noUnusedVariables rules now correctly recognise exported variables and functions declared in one embedded script block as usable from a sibling script block in Svelte and Vue components
- **fixed** — Fixed the HTML formatter's whitespace handling for marquee, noscript, video, audio, and object elements
- **added** — Added the nursery rule useAstroClientOnlyDirectiveValue, which reports Astro client:only directives without an initializer
- **fixed** — The useGenericFontNames rule now treats math as a valid generic font family
- **fixed** — The noComponentHookFactories rule now reports a use-prefixed variable only when a function is assigned to it directly

##### 2.5.9

###### Patch Changes

- [#11321](https://github.com/biomejs/biome/pull/11321) [`41386f3`](https://github.com/biomejs/biome/commit/41386f38935b299f1a1f759a2c7fdd5c2050bded) Thanks [@dyc3](https://github.com/dyc3)! - Fixed [#11315](https://github.com/biomejs/biome/issues/11315): The CSS parser now recovers at declaration boundaries after bogus declarations, allowing subsequent valid declarations to be parsed.

- [#11248](https://github.com/biomejs/biome/pull/11248) [`57b197e`](https://github.com/biomejs/biome/commit/57b197e6d5a2432ff6904afff24125e4d8ec01cd) Thanks [@yanthomasdev](https://github.com/yanthomasdev)! - Expanded the environment variable metadata used by `biome rage` to include `BIOME_BINARY`, `BIOME_LOG_FILE`, and `RUST_BACKTRACE` as well as reworded explanations for better readability.

- [#11377](https://github.com/biomejs/biome/pull/11377) [`a8798ea`](https://github.com/biomejs/biome/commit/a8798ea9f2569fab4524704c99a8e2fe45c2ca32) Thanks [@Netail](https://github.com/Netail)! - Added a new nursery rule [`useNamedLayer`](https://biomejs.dev/linter/rules/use-named-layer) which disallows anonymous cascade layers.

  ```css
  @layer {
    a {
      color: red;
    }
  }
  ```

- [#11327](https://github.com/biomejs/biome/pull/11327) [`6771cf5`](https://github.com/biomejs/biome/commit/6771cf5bd2e64f256468a33b811adec8e793d933) Thanks [@dyc3](https://github.com/dyc3)! - The HTML formatter now preserves meaningful blank lines in HTML, including spacing after elements with trailing spaces and blank lines between comment groups.

  ```diff
   <div>
     <!-- first group -->
  +
     <!-- second group -->
   </div>
  ```

- [#10312](https://github.com/biomejs/biome/pull/10312) [`ba8aa18`](https://github.com/biomejs/biome/commit/ba8aa183371b3080691ed80e5a9f6f0239cf451b) Thanks [@dyc3](https://github.com/dyc3)! - Added the nursery rule [`useTailwindShorthandClasses`](https://biomejs.dev/linter/rules/use-tailwind-shorthand-classes/), which suggests shorter Tailwind utility classes. For example, the rule suggests replacing `w-4 h-4` with `size-4`.

- [#11333](https://github.com/biomejs/biome/pull/11333) [`715e0cd`](https://github.com/biomejs/biome/commit/715e0cd1b3e6c88d153554901a659378c728e408) Thanks [@kkkhs](https://github.com/kkkhs)! - Fixed [#11328](https://github.com/biomejs/biome/issues/11328): `lint/nursery/useExpect` now recognizes Vitest Browser Mode `expect.element()` calls as assertions.

- [#11343](https://github.com/biomejs/biome/pull/11343) [`9b98211`](https://github.com/biomejs/biome/commit/9b982113dba8b37c163662d59611ecba0fc02f5a) Thanks [@johncarmack1984](https://github.com/johncarmack1984)! - Fixed [#11311](https://github.com/biomejs/biome/issues/11311): the CSS parser now accepts Tailwind container-query variant names in `@variant`, such as `@xl` and `@max-xl`. These previously produced a parse error and a [`noUnknownAtRules`](https://biomejs.dev/linter/rules/no-unknown-at-rules/) diagnostic.

  ```css
  @variant @xl {
    div {
      background: red;
    }
  }
  ```

- [#11220](https://github.com/biomejs/biome/pull/11220) [`3e8c488`](https://github.com/biomejs/biome/commit/3e8c4887c4ef87df45f56aafa4fbc5f497dae42f) Thanks [@santichausis](https://github.com/santichausis)! - Fixed [#9541](https://github.com/biomejs/biome/issues/9541): [`noUndeclaredVariables`](https://biomejs.dev/linter/rules/no-undeclared-variables/), [`noUnusedImports`](https://biomejs.dev/linter/rules/no-unused-imports/), and [`noUnusedVariables`](https://biomejs.dev/linter/rules/no-unused-variables/) now correctly recognise exported variables and functions declared in one embedded `<script>` block as usable from a sibling `<script>` block, in Svelte's `<script module>`/`<script>` pair and Vue's non-`setup` `<script>` blocks.

  For example, Biome no longer reports `greet` as undeclared in the following Svelte component:

  ```svelte
  <script module>
    export function greet() {
      console.log("Hello!");
    }
  </script>

_[Truncated at 4000 characters — full notes: https://github.com/biomejs/biome/releases/tag/%40biomejs/biome%402.5.9]_