v2.3.14

Compare Source

Patch Changes

• #​8921 29e2435 Thanks @​siketyan! - Fixed #​8759: The useConsistentTypeDefinitions rule no longer converts empty object type declarations into interfaces, as it will conflict with the noEmptyInterface rule and can cause an infinite loop when both rules are enabled.

• #​8928 ccaeac4 Thanks @​taga3s! - Added the nursery rule useGlobalThis. This rule enforces using globalThis over window, self and global.

• #​8602 9a18daa Thanks @​dyc3! - Added the new nursery rule noVueArrowFuncInWatch. This rule forbids using arrow functions in watchers in Vue components, because arrow functions do not give access to the component instance (via this), while regular functions do.

• #​8905 9b1eea8 Thanks @​ryan-m-walker! - Fixed #​8428: Improved parsing recovery when encountering qualified rules inside CSS @page at-rule blocks.

• #​8900 f788cff Thanks @​mdevils! - Fixed #​8802: useExhaustiveDependencies now correctly suggests dependencies without including callback-scoped variables or method names.

  When accessing object properties with a callback-scoped variable, only the object path is suggested:

  // Now correctly suggests `props.value` instead of `props.value[day]`
  useMemo(() => {
    return WeekdayValues.filter((day) => props.value[day]);
  }, [props.value]);

  When calling methods on objects, only the object is suggested as a dependency:

  // Now correctly suggests `props.data` instead of `props.data.forEach`
  useMemo(() => {
    props.data.forEach((item) => console.log(item));
  }, [props.data]);

• #​8913 e1e20ea Thanks @​dyc3! - Fixed #​8363: HTML parser no longer crashes when encountering a < character followed by a digit in text content (e.g., <12 months). The parser now correctly emits an "Unescaped < bracket character" error instead of treating <12 as a tag name and crashing.

• #​8910 2fb63a4 Thanks @​dyc3! - Fixed #​8774: Type aliases with generic parameters that have extends constraints now properly indent comments after the equals sign.

  Previously, comments after the = in type aliases with extends constraints were not indented:

  -type A<B, C extends D> = // Some comment
  -undefined;
  +type A<B, C extends D> =
  +    // Some comment
  +    undefined;

• #​8916 ea4bd04 Thanks @​ryan-m-walker! - Fixed #​4013, where comments in member chains caused unnecessary line breaks.

  // Before
  aFunction.b().c.d();
  
  // After
  aFunction.b().c.d();

• #​8945 fa66fe3 Thanks @​fireairforce! - Fixed #​8354: Don't remove quotes when type memeber is new.

  // Input:
  type X = {
    "new"(): string;
    "foo"(): string;
  };
  
  // Format Output:
  type X = {
    "new()": string;
    foo(): string;
  };

• #​8927 0ef3da5 Thanks @​littleKitchen! - Fixed #​8907: useExhaustiveDependencies now correctly recognizes stable hook results (like useState setters and useRef values) when declared with let.

• #​8931 4561751 Thanks @​koshin01! - Added the new nursery rule noRedundantDefaultExport, which flags redundant default exports where the default export references the same identifier as a named export.

• #​8900 f788cff Thanks @​mdevils! - Fixed #​8883: useExhaustiveDependencies no longer produces false positives when props are destructured in the function body of arrow function components without parentheses around the parameter.

  type Props = { msg: string };
  
  // Arrow function without parentheses around `props`
  const Component: React.FC<Props> = (props) => {
    const { msg } = props;
    // Previously, this incorrectly reported `msg` as unnecessary
    useEffect(() => console.log(msg), [msg]);
  };

• #​8861 3531687 Thanks @​dyc3! - Added the noDeprecatedMediaType CSS rule to flag deprecated media types like tv and handheld.

• #​8775 7ea71cd Thanks @​igas! - Fixed the noUnnecessararyConditions rule to prevent trigger for optional fallback patterns.

• #​8860 95f1eea Thanks @​dyc3! - Added the nursery rule noHexColors, which flags the use of hexadecimal color codes in CSS and suggests using named colors or RGB/RGBA/HSL/HSLA formats instead.

• #​8786 d876a38 Thanks @​Bertie690! - Added the nursery rule useConsistentMethodSignatures.
  Inspired by the similarly named version from typescript-eslint, this rule aims to enforce a consistent style for methods used inside object types and interfaces.

Examples

Invalid code with style set to "property" (the default):

interface Foo {
  method(a: string): void;
}

Invalid code with style set to "method":

type Bar = {
  prop: (a: string) => void;
}

• #​8864 5e97119 Thanks @​dyc3! - Improved the summary provided by biome migrate eslint to be clearer on why rules were not migrated. Biome now specifies a reason when a rule is not migrated, such as being incompatible with the formatter or not implemented yet. This helps users make more informed decisions when migrating their ESLint configurations to Biome.

• #​8924 99b4cd1 Thanks @​tmohammad78! - Fixed #​8920: noUnknownFunction now knows about sibling-count, and sibling-index css functions

• #​8900 f788cff Thanks @​mdevils! - Fixed #​8885: useExhaustiveDependencies no longer incorrectly reports variables as unnecessary dependencies when they are derived from expressions containing post/pre-increment operators (++/--) or compound assignment operators (+=, -=, etc.).

  let renderCount = 0;
  
  export const MyComponent = () => {
    // `count` is now correctly recognized as a required dependency
    // because `renderCount++` can produce different values between renders
    const count = renderCount++;
  
    useEffect(() => {
      console.log(count);
    }, [count]); // no longer reports `count` as unnecessary
  };

• #​8619 d78e01d Thanks @​Netail! - Added the nursery rule useInputName. Require mutation arguments to be called “input”, and the input type to be called Mutation name + “Input”.

  Invalid:

  type Mutation {
    SetMessage(message: String): String
  }

• #​8922 871b45e Thanks @​siketyan! - Fixed #​8829: Revamped the noGlobalDirnameFilename rule to catch many false negatives that have not been reported.

v2.3.13

Compare Source

Patch Changes

• #​8815 f924f23 Thanks @​dyc3! - Improved useVueValidVOn to be more closely aligned with the source rule. It will now properly allow modifiers for all possible keyboard events. It should have better performance when there are no violations of the rule as well.

  Now treated valid:

  <div @&#8203;keydown.arrow-down="handler"></div>
  <div @&#8203;keydown.a="handler"></div>
  <div @&#8203;keydown.b="handler"></div>
  <div @&#8203;keydown.27="foo"></div>

• #​8856 85f81f9 Thanks @​dyc3! - Fixed #​8710: Biome now parses Vue dynamic slot shorthand arguments that use template literals in [].

• #​8850 2a190e0 Thanks @​dyc3! - Fixed #​8708: Tailwind @utility directives now parse functional utility names like px-* when Tailwind directives are enabled.

• #​8863 79386e0 Thanks @​dyc3! - Fixed an issue with biome migrate eslint where it couldn't detect rules for CSS, GraphQL, and HTML.

• #​8771 6f56b6e Thanks @​lghuahua! - Fix the --reporter=summary output incorrectly merging and displaying wrong issue counts for different rules. Fixes #​8730

• #​8714 ac3a71f Thanks @​Netail! - Added new nursery rule use-consistent-enum-value-type. This rule disallows enums from having both number and string members.

v2.3.12

Compare Source

Patch Changes

• #​8653 047576d Thanks @​dyc3! - Added new nursery rule noDuplicateAttributes to forbid duplicate attributes in HTML elements.

• #​8648 96d09f4 Thanks @​BaeSeokJae! - Added a new nursery rule noVueOptionsApi.

  Biome now reports Vue Options API usage, which is incompatible with Vue 3.6's Vapor Mode.
  This rule detects Options API patterns in <script> blocks, defineComponent(), and createApp() calls,
  helping prepare codebases for Vapor Mode adoption.

  For example, the following now triggers this rule:

  <script>
  export default {
    data() {
      return { count: 0 };
    },
  };
  </script>

• #​8832 b08270b Thanks @​Exudev! - Fixed #​8809, #​7985, and #​8136: the noSecrets rule no longer reports false positives on common CamelCase identifiers like paddingBottom, backgroundColor, unhandledRejection, uncaughtException, and IngestGatewayLogGroup.

  The entropy calculation algorithm now uses "average run length" to distinguish between legitimate CamelCase patterns (which have longer runs of same-case letters) and suspicious alternating case patterns (which have short runs).

• #​8793 c19fb0e Thanks @​TheBaconWizard! - Properly handle parameters metavariables for arrow_function GritQL queries. The following biome search command no longer throws an error:

  biome search 'arrow_function(parameters=$parameters, body=$body)'

• #​8561 981affb Thanks @​wataryooou! - Fixed noUnusedVariables to ignore type parameters declared in ambient contexts such as declare module blocks.

• #​8817 652cfbb Thanks @​dyc3! - Fixed #​8765: The HTML parser can now parse directive modifiers with a single colon, e.g. @keydown.:.

• #​8704 a1914d4 Thanks @​Netail! - Added the nursery rule noRootType.
  Disallow the usage of specified root types. (e.g. mutation and/or subscription)

  Invalid:

  {
    "options": {
      "disallow": ["mutation"]
    }
  }

  type Mutation {
    SetMessage(message: String): String
  }

• #​8712 251b47b Thanks @​Netail! - Renamed the following GraphQL nursery rules to match the Biome standard:

  • useUniqueArgumentNames -> noDuplicateArgumentNames
  • useUniqueFieldDefinitionNames -> noDuplicateFieldDefinitionNames
  • useUniqueGraphqlOperationName -> noDuplicateGraphqlOperationName
  • useUniqueInputFieldNames -> noDuplicateInputFieldNames
  • useUniqueVariableNames -> noDuplicateVariableNames

  Run the biome migrate --write command to automatically update the configuration file.

• #​7602 957cd8e Thanks @​kedevked! - Added the nursery lint rule useErrorCause.

  This rule enforces that errors caught in a catch clause are not rethrown without wrapping them in a new Error object and specifying the original error as the cause. This helps preserve the error’s stack trace and context for better debugging.

  It can be configured with the following option:

  • requireCatchParameter: (default: true)
    • When true, the rule requires that catch clauses have a parameter. If a throw statement appears inside a catch clause without a parameter, it will be flagged.

  Invalid examples:

  try {
    foo();
  } catch {
    throw new Error("fail");
  }

  try {
    foo();
  } catch (err) {
    throw new Error(err.message);
  }

  Valid examples:

  try {
    foo();
  } catch (err) {
    throw new Error("fail", { cause: err });
  }

  try {
    foo();
  } catch (error) {
    throw new Error("Something went wrong", { cause: error });
  }

  Valid example when requireCatchParameter is false:

  Valid:

  try {
    foo();
  } catch {
    throw new Error("fail");
  }

• #​8725 95aba98 Thanks @​dyc3! - Fixed #​8715: The CSS parser will now recover slightly better if a semicolon is missing from Tailwind's @apply at-rule.

• #​8616 4ee3bda Thanks @​Netail! - Added the nursery rule useLoneAnonymousOperation. Disallow anonymous operations when more than one operation specified in document.

  Invalid:

  query {
    fieldA
  }
  
  query B {
    fieldB
  }

• #​8624 291c9f2 Thanks @​taga3s! - Added the nursery rule useInlineScriptId to the Next.js domain.
  This rule enforces id attribute on next/script components with inline content or dangerouslySetInnerHTML.

  The following code is invalid:

  import Script from "next/script";
  
  export default function Page() {
    return (
      <Script>{`console.log('Hello');`}</Script> // must have `id` attribute
    );
  }

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​3512:
  useExhaustiveDependencies now properly handles nested destructuring patterns
  from hook results.

  const [[x, y], setXY] = useState([1, 2]);
  useEffect(() => {
    console.log(x, y);
  }, [x, y]); // x and y are now correctly recognized as unstable

• #​8757 17ed9d3 Thanks @​Netail! - Added the nursery rule noDivRegex. Disallow equal signs explicitly at the beginning of regular expressions.

  Invalid:

  var f = function () {
    return /=foo/;
  };

• #​8836 aab1d17 Thanks @​dyc3! - Fixed #​7858: Biome now parses Astro files with empty frontmatter blocks.

• #​8755 3a15c29 Thanks @​arturalkaim! - Fixed #​6670. The $filename metavariable can now be used in GritQL where clauses to filter matches by filename.

• #​8821 63e68a1 Thanks @​playhardgopro! - Fixed several bugs in Vue conditional rules (useVueValidVIf, useVueValidVElse, and useVueValidVElseIf) related to whitespace handling, newlines, and self-closing tags.

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​3685:
  useExhaustiveDependencies now properly handles transparent expression
  wrappers like non-null assertions and type assertions in dependency comparisons.

  useMemo(() => Boolean(myObj!.x), [myObj!.x]); // No longer reports incorrect diagnostics
  useMemo(() => myObj!.x?.y === true, [myObj!.x?.y]); // Now correctly matches dependencies

• #​8597 f764007 Thanks @​Netail! - Added the nursery rule noDuplicateEnumValueNames. Enforce unique enum value names.

  Invalid:

  enum A {
    TEST
    TesT
  }

• #​8679 33dfd7c Thanks @​ematipico! - Fixed #​8678. Now Biome correctly parses components inside Vue, Svelte and Astro files when they have the same name of self-closing elements.

• #​8617 31a9bfe Thanks @​Netail! - Added the nursery rule useLoneExecutableDefinition. Require queries, mutations, subscriptions or fragments to be located in separate files.

  Invalid:

  query Foo {
    id
  }
  
  fragment Bar on Baz {
    id
  }

• #​8697 8519669 Thanks @​Faizanq! - Added the nursery lint rule noExcessiveLinesPerFile to CSS and GraphQL.

• #​8711 365f7aa Thanks @​Netail! - Added new nursery rule noDuplicateEnumValues, which disallows defining an enum with multiple members initialized to the same value.

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​5914:
  useExhaustiveDependencies now properly handles variables declared in the same
  statement.

  const varA = Math.random(),
    varB = useMemo(() => varA, [varA]); // varA is now correctly recognized as needed

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​8427:
  useExhaustiveDependencies now properly resolves variable references to detect
  captured dependencies.

  const fe = fetchEntity;
  useEffect(() => {
    fe(id);
  }, [id, fe]); // fe is now correctly detected as needed

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​8484:
  useExhaustiveDependencies now properly handles member access on stable hook
  results.

  const stableObj = useStable();
  useMemo(() => {
    return stableObj.stableValue; // stableObj.stableValue is now correctly recognized as stable
  }, []);

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​7982:
  useExhaustiveDependencies now properly handles callback expressions with type
  assertions.

  const callback = useCallback(
    (() => {
      return count * 2;
    }) as Function,
    [count], // count is now correctly detected
  );

• #​8766 39eb545 Thanks @​Netail! - Fixed #​8761: Reverted wrapping the URL of rule descriptions with <>, causing broken URLs in VSCode.

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​3080:
  useExhaustiveDependencies now properly analyzes captures within referenced
  functions passed to hooks.

  function myEffect() {
    console.log(foo, bar);
  }
  useEffect(myEffect, [foo, bar]); // foo and bar are now correctly detected

• #​8740 4962ed0 Thanks @​Netail! - Extra rule source references. biome migrate eslint should do a bit better detecting rules in your eslint configurations.

• #​8776 395746f Thanks @​codiini! - Fixed #​6003: noUselessUndefinedInitialization no longer reports exported variables initialized to undefined. In Svelte 4, this pattern is used to declare optional component props.

• #​8767 0d15370 Thanks @​mdevils! - Fixed #​4248:
  useExhaustiveDependencies now correctly handles function props passed as
  callbacks.

  const data = React.useMemo(getData, [getData]); // getData is now correctly recognized as needed

• #​8819 bc191ff Thanks @​Netail! - Fixed #​6567:
  noUnknownProperty now ignores unknown properties in at-rules which support descriptors.

• #​8787 adb652f Thanks @​tuyuritio! - Fixed #​8777: Add support for :active-view-transition pseudo-class.

• #​8639 6577e32 Thanks @​ohnoah! - Added the nursery lint rule noExcessiveLinesPerFile.
  Biome now reports files that exceed a configurable line limit.

  // maxLines: 2
  const a = 1;
  const b = 2;
  const c = 3;

• #​8753 71b5c6e Thanks @​Netail! - Added the nursery rule noExcessiveClassesPerFile. Enforce a maximum number of classes per file.

  Invalid:

  class Foo {}
  class Bar {}

• #​8754 d6b2bda Thanks @​Netail! - Added the nursery rule noFloatingClasses. Disallow new operators outside of assignments or comparisons.

  Invalid:

  new Date();

v2.3.11

Compare Source

Patch Changes

• #​8583 83be210 Thanks @​dyc3! - Added the new nursery rule useVueValidTemplateRoot.

  This rule validates only root-level <template> elements in Vue single-file components. If the <template> has a src attribute, it must be empty. Otherwise, it must contain content.

  Invalid examples:

  <template src="./foo.html">content</template>

  <template></template>

  Valid examples:

  <template>content</template>

  <template src="./foo.html"></template>

• #​8586 df8fe06 Thanks @​dyc3! - Added a new nursery rule useVueConsistentVBindStyle. Enforces consistent v-bind style (:prop shorthand vs v-bind:prop longhand). Default prefers shorthand; configurable via rule options.

• #​8587 9a8c98d Thanks @​dyc3! - Added the rule useVueVForKey, which enforces that any element using v-for also specifies a key.

  Invalid

  <li v-for="item in items">{{ item }}</li>

  Valid

  <li v-for="item in items" :key="item.id">{{ item }}</li>

• #​8586 df8fe06 Thanks @​dyc3! - Added a new nursery rule useVueConsistentVOnStyle. Enforces consistent v-on style (@event shorthand vs v-on:event longhand). Default prefers shorthand; configurable via rule options.

• #​8583 83be210 Thanks @​dyc3! - Added the new nursery rule useVueValidVOnce. Enforces that usages of the v-once directive in Vue.js SFC are valid.

  <!-- Valid -->
  <div v-once />
  
  <!-- Invalid -->
  <div v-once:aaa />
  <div v-once.bbb />
  <div v-once="ccc" />

• #​8498 d80fa41 Thanks @​tt-a1i! - Fixed #​8494. Extended noUndeclaredEnvVars to support bracket notation (process.env["VAR"], import.meta.env["VAR"]), Bun runtime (Bun.env.VAR, Bun.env["VAR"]), and Deno runtime (Deno.env.get("VAR")).

• #​8509 574a909 Thanks @​ematipico! - Added support for parsing and formatting the Svelte {#await} syntax, when html.experimentalFullSupportEnabled is set to true.

  -{#await promise  then name }
  +{#await promise then name}
  
  -{:catch    name}
  +{:catch name}
  
  {/await}

• #​8316 d64e92d Thanks @​washbin! - Added the new nursery rule noMultiAssign. This rule helps to prevent multiple chained assignments.

  For example, the following code triggers because there are two assignment expressions in the same statement.

  const a = (b = 0);

• #​8592 a5f59cd Thanks @​Netail! - Added the nursery rule useUniqueInputFieldNames. Require fields within an input object to be unique.

  Invalid:

  query A($x: Int, $x: Int) {
    field
  }

• #​8524 17a6156 Thanks @​JacquesLeupin! - Fixed #​8488: Relative plugin paths are now resolved from the configuration file directory, including when configurations are merged (e.g. extends: "//").

• #​8655 3260ec9 Thanks @​JacquesLeupin! - Fixed #​8636: Biome's CSS formatter now breaks comma-separated declaration values at top-level commas when wrapping.

• #​8537 cc3e851 Thanks @​dibashthapa! - Fixed #​8491: Resolved false positive errors for safe boolean expressions. There are still pending fixes. Head to #​8491 (comment) for more details

  This new change will check for safe boolean expressions in variable declarations.

  For example,

  Valid:

  let isOne = 1;
  let isPositiveNumber = number > 0;
  
  return (
    <div>
      {" "}
      {isOne && "One"} {isPositiveNumber && "Is positive"}
    </div>
  );

  Invalid:

  let emptyStr = "";
  let isZero = 0;
  
  return (
    <div>
      {emptyStr && "Empty String"} {isZero && "Number is zero"}{" "}
    </div>
  );

• #​8511 16a9036 Thanks @​ematipico! - Improved the diagnostics of the rules useSortedClasses and noUnnecessaryConditions. The diagnostics now state that these rules are a work in progress and link to the relevant GitHub issue.

• #​8521 a704be9 Thanks @​ToBinio! - Added the nursery rule useVueConsistentDefinePropsDeclaration, which enforces consistent defineProps declaration style.

Invalid

<script setup lang="ts">
const props = defineProps({
  kind: { type: String },
});
</script>

Valid

<script setup lang="ts">
const props = defineProps<{
  kind: string;
}>();
</script>

• #​8595 7c85bf0 Thanks @​dyc3! - Fixed #​8584: The HTML formatter will preserve whitespace after some elements and embedded expressions, which more closely aligns with Prettier's behavior.

  - <h1>Hello, {framework}and Svelte!</h1>
  + <h1>Hello, {framework} and Svelte!</h1>

• #​8598 5e85d43 Thanks @​Netail! - Added the nursery rule useUniqueFieldDefinitionNames. Require all fields of a type to be unique.

  Invalid:

  type SomeObject {
    foo: String
    foo: String
  }

• #​8495 b573d14 Thanks @​taga3s! - Fixed #​8405: noMisusedPromises now emits warnings/errors when a function returns union types such as T | Promise<T> which is used in conditionals.

  const a = (): boolean | Promise<boolean> => Promise.resolve(true);
  if (a()) {
  } // Now correctly flagged

• #​8632 0be7d12 Thanks @​Bertie690! - The documentation & rule sources for lint/complexity/noBannedTypes have been updated to fix a few oversights.

  In addition to some general typo fixes:

  • The rule now recommends Record<keyof any, never> instead of Record<string, never> (the latter of which incorrectly allows symbol-keyed properties).

  • The rule mentions an alternate method to enforce object emptiness involving unique symbol-based guards used by type-fest and many other packages:

    declare const mySym: unique symbol;
    
    // Since this type's only property is an unexported `unique symbol`, nothing that imports it can specify any properties directly
    // (as far as excess property checks go)
    export type EmptyObject = { [mySym]?: never };
    export type IsEmptyObject<T> = T extends EmptyObject ? true : false;

  The rule's listed sources have been updated as well to reflect the original source rule (ban-types) having been split into 3 separate rules circa April 2024.

• #​8580 a3a1ad2 Thanks @​taga3s! - Added the nursery rule noBeforeInteractiveScriptOutsideDocument to the Next.js domain.
  This rule prevents usage of next/script's beforeInteractive strategy outside of pages/_document.js.

• #​8493 5fc24f4 Thanks @​ematipico! - Added support for parsing and formatting the Svelte {#each} syntax, when html.experimentalFullSupportEnabled is set to true.

  - {#each items   as item  }
  + {#each items as item}
  
  {/each}

• #​8546 0196c0e Thanks @​Zaczero! - Hardened union static-member type flattening in edge cases (e.g. unions containing unknown or inferred expression types). This keeps inference conservative and avoids unstable type growth in node = node.parent-style loops.

• [#​8569](https://redirect.github.com/biomejs/biome/pull/85