All versions since 2.3.2

All versions

2.3.2

Patch Changes

#7859 c600618 Thanks @Netail! - Added the nursery rule noIncrementDecrement, disallows the usage of the unary operators ++ and —.
#7901 0d17b05 Thanks @ematipico! - Fixed #7837, where Biome couldn’t properly parse text expressions that contained nested curly brackets. This was breaking parsing in Astro and Svelte files.
#7874 e617d36 Thanks @Bertie690! - Fixed #7230: noUselessStringConcat no longer emits false positives for multi-line strings with leading + operators.

Previously, the rule did not check for leading newlines on the + operator, emitting false positives if one occurred at the start of a line.
Notably, formatting with operatorLinebreak="before" would move the + operators to the start of lines automatically, resulting in spurious errors whenever a multi-line string was used.

Now, the rule correctly detects and ignores multi-line concatenations with leading operators as well, working regardless of the setting of operatorLinebreak.

Example
```
1
// The following code used to error if the `+` operators were at the start of lines (as opposed to the end).
2
// Now, the rule correctly recognizes this as a stylistic concatenation and ignores it.
3
const reallyLongStringThatShouldNotError =
4
  "Lorem ipsum dolor sit amet consectetur adipiscing elit." +
5
  "Quisque faucibus ex sapien vitae pellentesque sem placerat." +
6
  "In id cursus mi pretium tellus duis convallis." +
7
  "Tempus leo eu aenean sed diam urna tempor. Pulvinar vivamus fringilla";
```
#7786 33ffcd5 Thanks @daivinhtran! - Fixed #7601: Properly match Grit plugin’s code snippet with only one child.
#7901 0d17b05 Thanks @ematipico! - Fixed #7837, where Biome Language Server panicked when opening HTML-ish files when the experimental full support is enabled.

2.3.3

Patch Changes

#7907 57bd662 Thanks @ematipico! - Fixed #7839. Now the Biome parser correctly parses the Astro frontmatter even when a triple fence is inside quotes.
#7934 a35c496 Thanks @alissonlauffer! - Fixed #7919: The HTML parser now correctly handles Unicode BOM (Byte Order Mark) characters at the beginning of HTML files, ensuring proper parsing and tokenization.
#7869 c80361d Thanks @matanshavit! - Fixed #7864: Biome now preserves component tag name casing in Svelte, Astro, and Vue files.
#7926 69cecec Thanks @matanshavit! - Added the rule noParametersOnlyUsedInRecursion.

This rule detects function parameters that are exclusively used in recursive calls and can be removed to simplify the function signature since they are effectively unused.
```
1
function factorial(n, acc) {
2
  if (n === 0) return 1;
3
  return factorial(n - 1, acc); // acc is only used here
4
}
```
Fixes #6484.
#7774 2509b91 Thanks @dibashthapa! - Fixed #7657: Added the new rule no-unknown-property from ESLint
#7918 7165d06 Thanks @dyc3! - Fixed #7913: The CSS parser, with tailwindDirectives enabled, will now correctly handle @slot.
#7959 ffae203 Thanks @siketyan! - Fixed the Biome Language Server so it no longer returns an internal error when the formatter is disabled in the configuration.

2.3.4

Patch Changes

#7989 4855c4a Thanks @alissonlauffer! - Fixed a regression in Astro frontmatter parsing where comments inside quoted strings were incorrectly detected as actual comments. This caused the parser to prematurely terminate frontmatter parsing when encountering strings like const test = "//";. For example, the following Astro frontmatter now parses correctly:
```
1
---
2
const test = "// not a real comment";
3
---
```
#7968 0b28f5f Thanks @denbezrukov! - Refactored formatter to use strict Token element for better performance. The new Token variant is optimized for static, ASCII-only text (keywords, operators, punctuation) with the following constraints:
- ASCII only (no Unicode characters)
- No newlines (\n, \r)
- No tab characters (\t)
This enables faster printing and fitting logic by using bulk string operations (push_str, len()) instead of character-by-character iteration with Unicode width calculations.

#7941 19b8280 Thanks @Conaclos! - Fixed #7943. Rules’ options are now properly merged with the inherited options from a shared configuration.

This means that you can now override a specific option from a rule without resetting the other options to their default.

Given the following shared configuration:

1
{
2
  "linter": {
3
    "rules": {
4
      "style": {
5
        "useNamingConvention": {
6
          "level": "on",
7
          "options": {
8
            "strictCase": false,
9
            "conventions": [
10
              {
11
                "selector": { "kind": "variable", "scope": "global" },
12
                "formats": ["CONSTANT_CASE"]
13
              }
14
            ]
15
          }
16
        }
17
      }
18
    }
19
  }
20
}

And the user configuration that extends this shared configuration:

1
{
2
  "extends": ["shared.json"],
3
  "linter": {
4
    "rules": {
5
      "style": {
6
        "useNamingConvention": {
7
          "level": "on",
8
          "options": { "strictCase": true }
9
        }
10
      }
11
    }
12
  }
13
}

The obtained merged configuration is now as follows:

1
{
2
  "extends": ["shared.json"],
3
  "linter": {
4
    "rules": {
5
      "style": {
6
        "useNamingConvention": {
7
          "level": "on",
8
          "options": {
9
            "strictCase": true,
10
            "conventions": [
11
              {
12
                "selector": { "kind": "variable", "scope": "global" },
13
                "formats": ["CONSTANT_CASE"]
14
              }
15
            ]
16
          }
17
        }
18
      }
19
    }
20
  }
21
}

#7969 425963d Thanks @ematipico! - Added support for the Svelte syntax {@debug}. The Biome HTML parser is now able to parse and format the blocks:
```
1
{@debug     foo,bar,    something}
2
{@debug foo, bar, something}
```
#7986 3256f82 Thanks @lisiur! - Fixed #7981. Now Biome correctly detects and parses lang='tsx' and lang='jsx' languages when used inside in .vue files, when .experimentalFullSupportEnabled is enabled.
#7921 547c2da Thanks @dyc3! - Fixed #7854: The CSS parser, with tailwindDirectives enabled, will now parse @source inline("underline");.

#7856 c9e20c3 Thanks @Netail! - Added the nursery rule noContinue. Disallowing the usage of the continue statement, structured control flow statements such as if should be used instead.

Invalid:

1
let sum = 0,
2
  i;
3

4
for (i = 0; i < 10; i++) {
5
  if (i >= 5) {
6
    continue;
7
  }
8

9
  sum += i;
10
}

Valid:

1
let sum = 0,
2
  i;
3

4
for (i = 0; i < 10; i++) {
5
  if (i < 5) {
6
    sum += i;
7
  }
8
}

2.3.5

Patch Changes

#8023 96f3e77 Thanks @ematipico! - Added support Svelte syntax {@html}. Biome now is able to parse and format the Svelte syntax {@html}:
```
1
{@html   'div'}
2
{@html 'div'}
```
The contents of the expressions inside the {@html <expression>} aren’t formatted yet.
#8058 5f68bcc Thanks @ematipico! - Fixed a bug where the Biome Language Server would enable its project file watcher even when no project rules were enabled.

Now the watching of nested configuration files and nested ignore files is delegated to the editor, if their LSP spec supports it.
#8023 96f3e77 Thanks @ematipico! - Added support Svelte syntax {@render}. Biome now is able to parse and format the Svelte syntax {@render}:
```
1
{@render   sum(1, 2)   }
2
{@render sum(1, 2)}
```
The contents of the expressions inside the {@render <expression>} aren’t formatted yet.
#8006 f0612a5 Thanks @Bertie690! - Updated documentation and diagnostic for lint/complexity/noBannedTypes. The rule should have a more detailed description and diagnostic error message.
#8039 da70d8b Thanks @PFiS1737! - Biome now keeps a blank line after the frontmatter section in Astro files.
#8042 b7efa6f Thanks @dyc3! - The CSS Parser, with tailwindDirectives enabled, will now accept at rules like @media and @supports in @custom-variant shorthand syntax.
#8064 3ff9d45 Thanks @dibashthapa! - Fixed #7967: Fixed the issue with support for advanced SVG props
#8023 96f3e77 Thanks @ematipico! - Added support Svelte syntax {@attach}. Biome now is able to parse and format the Svelte syntax {@attach}:
```
1
<div {@attach    myAttachment   }>...</div>
2
<div {@attach myAttachment}>...</div>
```
The contents of the expressions inside the {@attach <expression>} aren’t formatted yet.
#8001 6e8a50e Thanks @ematipico! - Added support Svelte syntax {#key}. Biome now is able to parse and format the Svelte syntax {#key}:
```
1
{#key   expression} <div></div> {/key}
2
{#key expression}
3
  <div></div>
4
{/key}
```
The contents of the expressions inside the {#key <expression>} aren’t formatted yet.
#8023 96f3e77 Thanks @ematipico! - Added support Svelte syntax {@const}. Biome now is able to parse and format the Svelte syntax {@const}:
```
1
{@const   name = value}
2
{@const name = value}
```
The contents of the expressions inside the {@const <expression>} aren’t formatted yet.
#8044 8f77d4a Thanks @Netail! - Corrected rule source references. biome migrate eslint should do a bit better detecting rules in your eslint configurations.
#8065 1a2d1af Thanks @Netail! - Added the nursery rule useArraySortCompare. Require Array#sort and Array#toSorted calls to always provide a compareFunction.

Invalid:
```
1
const array = [];
2
array.sort();
```
Valid:
```
1
const array = [];
2
array.sort((a, b) => a - b);
```
#7673 a3a713d Thanks @dyc3! - The HTML parser is now able to parse vue directives. This enables us to write/port Vue lint rules that require inspecting the <template> section. However, this more complex parsing may result in parsing errors where there was none before. For those of you that have opted in to the experimental support (aka experimentalFullSupportEnabled), we greatly appreciate your help testing this out, and your bug reports.

#8031 fa6798a Thanks @ematipico! - Added support for the Svelte syntax {#if}{/if}. The Biome HTML parser is now able to parse and format the {#if}{/if} blocks:

1
<!-- if / else-if / else -->
2
{#if porridge.temperature > 100}
3
<p>too hot!</p>
4
  <p>too hot!</p>
5
{:else if 80 > porridge.temperature}
6
<p>too cold!</p>
7
  <p>too cold!</p>
8
{:else if 100 > porridge.temperature}
9
<p>too too cold!</p>
10
  <p>too too cold!</p>
11
{:else}
12
<p>just right!</p>
13
  <p>just right!</p>
14
{/if}

#8041 beeb7bb Thanks @dyc3! - The CSS parser, with tailwindDirectives enabled, will now accept lists of selectors in @custom-variant shorthand syntax.
```
1
@custom-variant cell (th:has(&), td:has(&));
```
#8028 c09e45c Thanks @fmajestic! - The GitLab reporter now outputs format errors.
#8037 78011b1 Thanks @PFiS1737! - indentScriptAndStyle no longer indents the frontmatter in Astro files.
#8009 6374b1f Thanks @tmcw! - Fixed an edge case in the useArrowFunction rule.

The rule no longer emits diagnostics for or offers to fix functions that reference the arguments object, because that object is undefined for arrow functions.

Valid example:
```
1
// Valid: this function cannot be transformed into an arrow function because
2
// arguments is not defined for arrow functions.
3
const getFirstArg = function () {
4
  return arguments[0];
5
};
```

2.3.6

Patch Changes

#8100 82b9a8e Thanks @Netail! - Added the nursery rule useFind. Enforce the use of Array.prototype.find() over Array.prototype.filter() followed by [0] when looking for a single result.

Invalid:
```
1
[1, 2, 3].filter((x) => x > 1)[0];
2

3
[1, 2, 3].filter((x) => x > 1).at(0);
```
#8118 dbc7021 Thanks @hirokiokada77! - Fixed #8117: useValidLang now accepts valid BCP 47 language tags with script subtags.

Valid:
```
1
<html lang="zh-Hans-CN"></html>
```
#7672 f1d5725 Thanks @Netail! - Added the nursery rule useConsistentGraphqlDescriptions, requiring all descriptions to follow the same style (either block or inline) inside GraphQL files.

Invalid:
```
1
enum EnumValue {
2
  "this is a description"
3
  DEFAULT
4
}
```
Valid:
```
1
enum EnumValue {
2
  """
3
  this is a description
4
  """
5
  DEFAULT
6
}
```
#8026 f102661 Thanks @matanshavit! - Fixed #8004: noParametersOnlyUsedInRecursion now correctly detects recursion by comparing function bindings instead of just names.

Previously, the rule incorrectly flagged parameters when a method had the same name as an outer function but called the outer function (not itself):
```
1
function notRecursive(arg) {
2
  return arg;
3
}
4

5
const obj = {
6
  notRecursive(arg) {
7
    return notRecursive(arg); // This calls the outer function, not the method itself
8
  },
9
};
```
Biome now properly distinguishes between these cases and will not report false positives.
#8097 5fc5416 Thanks @dyc3! - Added the nursery rule noVueVIfWithVFor. This rule disallows v-for and v-if on the same element.
```
1

2
<div v-for="item in items" v-if="item.isActive">
3
  {{ item.name }}
4
</div>
```
#8085 7983940 Thanks @Netail! - Added the nursery rule noForIn. Disallow iterating using a for-in loop.

Invalid:
```
1
for (const i in array) {
2
  console.log(i, array[i]);
3
}
```
#8086 2b41e82 Thanks @matanshavit! - Fixed #8045: The noNestedTernary rule now correctly detects nested ternary expressions even when they are wrapped in parentheses (e.g. foo ? (bar ? 1 : 2) : 3).

Previously, the rule would not flag nested ternaries like foo ? (bar ? 1 : 2) : 3 because the parentheses prevented detection. The rule now looks through parentheses to identify nested conditionals.

Previously not detected (now flagged):
```
1
const result = foo ? (bar ? 1 : 2) : 3;
```
Still valid (non-nested with parentheses):
```
1
const result = foo ? bar : baz;
```
#8075 e403868 Thanks @YTomm! - Fixed #7948: The useReadonlyClassProperties code fix when checkAllProperties is enabled will no longer insert a newline after readonly and the class property.
#8102 47d940e Thanks @lucasweng! - Fixed #8027. useReactFunctionComponents no longer reports class components that implement componentDidCatch using class expressions.

The rule now correctly recognizes error boundaries defined as class expressions:
```
1
const ErrorBoundary = class extends Component {
2
  componentDidCatch(error, info) {}
3

4
  render() {
5
    return this.props.children;
6
  }
7
};
```
#8097 5fc5416 Thanks @dyc3! - Added the nursery rule useVueHyphenatedAttributes, which encourages using kebab case for attribute names, per the Vue style guide’s recommendations.
```
1

2
<MyComponent myProp="value" />
3

4

5
<MyComponent my-prop="value" />
```

#8108 0f0a658 Thanks @Netail! - Added the nursery rule noSyncScripts. Prevent the usage of synchronous scripts.

Invalid:

1
<script src="https://third-party-script.js" />

Valid:

1
<script src="https://third-party-script.js" async />
2
<script src="https://third-party-script.js" defer />

#8098 1fdcaf0 Thanks @Jayllyz! - Added documentation URLs to rule descriptions in the JSON schema.
#8097 5fc5416 Thanks @dyc3! - Fixed an issue with the HTML parser where it would treat Vue directives with dynamic arguments as static arguments instead.
#7684 f4433b3 Thanks @vladimir-ivanov! - Changed noUnusedPrivateClassMembers to align more fully with meaningful reads.

This rule now distinguishes more carefully between writes and reads of private class members.
- A meaningful read is any access that affects program behavior.
- For example, this.#x += 1 both reads and writes #x, so it counts as usage.
- Pure writes without a read (e.g. this.#x = 1 with no getter) are no longer treated as usage.
This change ensures that private members are only considered “used” when they are actually read in a way that influences execution.

Invalid examples (previously valid)
```
1
class UsedMember {
2
  set #x(value) {
3
    doSomething(value);
4
  }
5

6
  foo() {
7
    // This assignment does not actually read #x, because there is no getter.
8
    // Previously, this was considered a usage, but now it’s correctly flagged.
9
    this.#x = 1;
10
  }
11
}
```
Valid example (Previously invalid)
```
1
class Foo {
2
  #usedOnlyInWriteStatement = 5;
3

4
  method() {
5
    // This counts as a meaningful read because we both read and write the value.
6
    this.#usedOnlyInWriteStatement += 42;
7
  }
8
}
```
#7684 f4433b3 Thanks @vladimir-ivanov! - Improved detection of used private class members

The analysis for private class members has been improved: now the tool only considers a private member “used” if it is actually referenced in the code.
- Previously, some private members might have been reported as used even if they weren’t actually accessed.
- With this change, only members that are truly read or called in the code are counted as used.
- Members that are never accessed will now be correctly reported as unused.
This makes reports about unused private members more accurate and helps you clean up truly unused code.

Example (previously valid)
```
1
type YesNo = "yes" | "no";
2

3
export class SampleYesNo {
4
  private yes: () => void;
5
  private no: () => void;
6
  private dontKnow: () => void; // <- will now report as unused
7

8
  on(action: YesNo): void {
9
    this[action]();
10
  }
11
}
```
#7681 b406db6 Thanks @kedevked! - Added the new lint rule, useSpread, ported from the ESLint rule prefer-spread.

This rule enforces the use of the spread syntax (...) over Function.prototype.apply() when calling variadic functions, as spread syntax is generally more concise and idiomatic in modern JavaScript (ES2015+).

The rule provides a safe fix.

Invalid
```
1
Math.max.apply(Math, args);
2
foo.apply(undefined, args);
3
obj.method.apply(obj, args);
```
Valid
```
1
Math.max(...args);
2
foo(...args);
3
obj.method(...args);
4

5
// Allowed: cases where the `this` binding is intentionally changed
6
foo.apply(otherObj, args);
```

#7287 aa55c8d Thanks @ToBinio! - Fixed #7205: The noDuplicateTestHooks rule now treats chained describe variants (e.g., describe.each/for/todo) as proper describe scopes, eliminating false positives.

The following code will no longer be a false positive:

1
describe("foo", () => {
2
  describe.for([])("baz", () => {
3
    beforeEach(() => {});
4
  });
5

6
  describe.todo("qux", () => {
7
    beforeEach(() => {});
8
  });
9

10
  describe.todo.each([])("baz", () => {
11
    beforeEach(() => {});
12
  });
13
});

#8013 0c0edd4 Thanks @Jayllyz! - Added the GraphQL nursery rule useUniqueGraphqlOperationName. This rule ensures that all GraphQL operations within a document have unique names.

Invalid:

1
query user {
2
  user {
3
    id
4
  }
5
}
6

7
query user {
8
  user {
9
    id
10
    email
11
  }
12
}

Valid:

1
query user {
2
  user {
3
    id
4
  }
5
}
6

7
query userWithEmail {
8
  user {
9
    id
10
    email
11
  }
12
}

#8084 c2983f9 Thanks @dyc3! - Fixed #8080: The HTML parser, when parsing Vue, can now properly handle Vue directives with no argument, modifiers, or initializer (e.g. v-else). It will no longer treat subsequent valid attributes as bogus.
```
1
<p v-else class="flex">World</p>
2

```
#8104 041196b Thanks @Conaclos! - Fixed noInvalidUseBeforeDeclaration. The rule no longer reports a use of an ambient variable before its declarations. The rule also completely ignores TypeScript declaration files. The following code is no longer reported as invalid:
```
1
CONSTANT;
2
declare const CONSTANT: number;
```
#8060 ba7b076 Thanks @dyc3! - Added the nursery rule useVueValidVBind, which enforces the validity of v-bind directives in Vue files.

Invalid v-bind usages include:
```
1
<Foo v-bind />
2

3
<Foo v-bind:foo />
4

5
<Foo v-bind:foo.bar="baz" />
6

```
#8113 fb8e3e7 Thanks @Conaclos! - Fixed noInvalidUseBeforeDeclaration. The rule now reports invalid use of classes, enums, and TypeScript’s import-equals before their declarations.

The following code is now reported as invalid:
```
1
new C();
2
class C {}
```
#8077 0170dcb Thanks @dyc3! - Added the rule useVueValidVElseIf to enforce valid v-else-if directives in Vue templates. This rule reports invalid v-else-if directives with missing conditional expressions or when not preceded by a v-if or v-else-if directive.
#8077 0170dcb Thanks @dyc3! - Added the rule useVueValidVElse to enforce valid v-else directives in Vue templates. This rule reports v-else directives that are not preceded by a v-if or v-else-if directive.
#8077 0170dcb Thanks @dyc3! - Added the rule useVueValidVHtml to enforce valid usage of the v-html directive in Vue templates. This rule reports v-html directives with missing expressions, unexpected arguments, or unexpected modifiers.
#8077 0170dcb Thanks @dyc3! - Added the rule useVueValidVIf to enforce valid v-if directives in Vue templates. It disallows arguments and modifiers, and ensures a value is provided.
#8077 0170dcb Thanks @dyc3! - Added the rule useVueValidVOn to enforce valid v-on directives in Vue templates. This rule reports invalid v-on / shorthand @ directives with missing event names, invalid modifiers, or missing handler expressions.

2.3.7

Patch Changes

#8169 7fdcec8 Thanks @arendjr! - Fixed #7999: Correctly place await after leading comment in auto-fix action from noFloatingPromises rule.
#8157 12d5b42 Thanks @Conaclos! - Fixed #8148. noInvalidUseBeforeDeclaration no longer reports some valid use before declarations.

The following code is no longer reported as invalid:
```
1
class classA {
2
  C = C;
3
}
4
const C = 0;
```
#8178 6ba4157 Thanks @dyc3! - Fixed #8174, where the HTML parser would parse 2 directives as a single directive because it would not reject whitespace in Vue directives. This would cause the formatter to erroneously merge the 2 directives into one, resulting in broken code.
```
1
<Component v-else:property="123" />
2
<Component v-else :property="123" />
```
#8088 0eb08e8 Thanks @db295! - Fixed #7876: The noUnusedImports rule now ignores imports that are used by @linkcode and @linkplain (previously supported @link and @see).

The following code will no longer be a false positive:
```
1
import type { a } from "a"
2

3
/**
4
 * {@linkcode a}
5
 */
6
function func() {}
```
#8119 8d64655 Thanks @ematipico! - Improved the detection of the rule noUnnecessaryConditions. Now the rule isn’t triggered for variables that are mutated inside a module.

This logic deviates from the original rule, hence noUnnecessaryConditions is now marked as “inspired”.

In the following example, hey starts as false, but then it’s assigned to a string. The rule isn’t triggered inside the if check.
```
1
let hey = false;
2

3
function test() {
4
  hey = "string";
5
}
6

7
if (hey) {
8
}
```
#8149 e0a02bf Thanks @Netail! - Fixed #8144: Improve noSyncScripts, ignore script tags with type="module" as these are always non-blocking.
#8182 e9f068e Thanks @hirokiokada77! - Fixed #7877: Range suppressions now handle suppressed categories properly.

Valid:
```
1
// biome-ignore-start lint: explanation
2
const foo = 1;
3
// biome-ignore-end lint: explanation
```
#8111 bf1a836 Thanks @ryan-m-walker! - Added support for parsing and formatting the CSS if function.

Example
```
1
.basic-style {
2
  color: if(style(--scheme: dark): #eeeeee; else: #000000;);
3
}
```
#8173 7fc07c1 Thanks @ematipico! - Fixed #8138 by reverting an internal refactor that caused a regression to the rule noUnusedPrivateClassMembers.
#8119 8d64655 Thanks @ematipico! - Improved the type inference engine, by resolving types for variables that are assigned to multiple values.
#8158 fb1458b Thanks @dyc3! - Added the useVueValidVText lint rule to enforce valid v-text directives. The rule reports when v-text has an argument, has modifiers, or is missing a value.

Invalid:
```
1
<div v-text />
2

3
<div v-text:aaa="foo" />
4

5
<div v-text.bbb="foo" />
6

```
#8158 fb1458b Thanks @dyc3! - Fixed useVueValidVHtml so that it will now flag empty strings, e.g. v-html=""
#7078 bb7a15c Thanks @emilyinure! - Fixed #6675: Now only flags noAccumulatingSpread on Object.assign when a new object is being allocated on each iteration. Before, all cases using Object.assign with reduce parameters were warned despite not making new allocations.

The following code will no longer be a false positive:
```
1
foo.reduce((acc, bar) => Object.assign(acc, bar), {});
```
The following cases which do make new allocations will continue to warn:
```
1
foo.reduce((acc, bar) => Object.assign({}, acc, bar), {});
```
#8175 0c8349e Thanks @ryan-m-walker! - Fixed CSS formatting of dimension units to use correct casing for Q, Hz and kHz.

Before:
```
1
.cssUnits {
2
  a: 1Q;
3
  b: 1Hz;
4
  c: 1kHz;
5
}
```
After:
```
1
.cssUnits {
2
  a: 1Q;
3
  b: 1Hz;
4
  c: 1kHz;
5
}
```

2.3.8

Patch Changes

#8188 4ca088c Thanks @ematipico! - Fixed #7390, where Biome couldn’t apply the correct configuration passed via --config-path.

If you have multiple root configuration files, running any command with --config-path will now apply the chosen configuration file.
#8171 79adaea Thanks @dibashthapa! - Added the new rule noLeakedRender. This rule helps prevent potential leaks when rendering components that use binary expressions or ternaries.

For example, the following code triggers the rule because the component would render 0:
```
1
const Component = () => {
2
  const count = 0;
3
  return <div>{count && <span>Count: {count}</span>}</div>;
4
};
```
#8116 b537918 Thanks @Netail! - Added the nursery rule noDuplicatedSpreadProps. Disallow JSX prop spreading the same identifier multiple times.

Invalid:
```
1
<div {...props} something="else" {...props} />
```
#8256 f1e4696 Thanks @cormacrelf! - Fixed a bug where logs were discarded (the kind from --log-level=info etc.). This is a regression introduced after an internal refactor that wasn’t adequately tested.
#8226 3f19b52 Thanks @dyc3! - Fixed #8222: The HTML parser, with Vue directives enabled, can now parse v-slot shorthand syntax, e.g. <template #foo>.
#8007 182ecdc Thanks @brandonmcconnell! - Added support for dollar-sign-prefixed filenames in the useFilenamingConvention rule.

Biome now allows filenames starting with the dollar-sign (e.g. $postId.tsx) by default to support naming conventions used by frameworks such as TanStack Start for file-based-routing.
#8218 91484d1 Thanks @hirokiokada77! - Added the noMultiStr rule, which disallows creating multiline strings by escaping newlines.

Invalid:
```
1
const foo =
2
  "Line 1\n\
3
Line 2";
```
Valid:
```
1
const foo = "Line 1\nLine 2";
2
const bar = `Line 1
3
Line 2`;
```

#8225 98ca2ae Thanks @ongyuxing! - Fixed #7806: Prefer breaking after the assignment operator for conditional types with generic parameters to match Prettier.

1
type True = unknown extends Type<
2
  "many",
3
  "generic",
4
  "parameters",
5
  "one",
6
  "two",
7
  "three"
8
>
9
  ? true
10
  : false;
11
type True =
12
  unknown extends Type<"many", "generic", "parameters", "one", "two", "three">
13
    ? true
14
    : false;

#6765 23f7855 Thanks @emilyinure! - Fixed #6569: Allow files to export from themselves with noImportCycles.

This means the following is now allowed:

1
export function example() {
2
  return 1;
3
}
4

5
// Re-exports all named exports from the current module under a single namespace
6
// and then imports the namespace from the current module.
7
// Allows for encapsulating functions/variables into a namespace instead
8
// of using a static class.
9
export * as Example from "./example.js";
10

11
import { Example } from "./example.js";

#8214 68c052e Thanks @hirokiokada77! - Added the noEqualsToNull rule, which enforces the use of === and !== for comparison with null instead of == or !=.

Invalid:
```
1
foo == null;
2
foo != null;
```
Valid:
```
1
foo === null;
2
foo !== null;
```
#8219 793bb9a Thanks @dyc3! - Fixed #8190: The HTML parser will now parse Vue event handlers that contain : correctly, e.g. @update:modelValue="onUpdate".
#8259 4a9139b Thanks @hirokiokada77! - Fixed #8254: The noParameterAssign rule with propertyAssignment: "deny" was incorrectly reporting an error when a function parameter was used on the right-hand side of an assignment to a local variable’s property.

The rule should only flag assignments that modify the parameter binding or its properties (L-value), not the use of its value.

Valid:
```
1
(input) => {
2
  const local = { property: 0 };
3
  local.property = input;
4
};
```
#8201 cd2edd7 Thanks @Netail! - Added the nursery rule noTernary. Disallow ternary operators.

Invalid:
```
1
const foo = isBar ? baz : qux;
```
#8172 de98933 Thanks @JeremyMoeglich! - Fixed #8145: handling of large hex literals, which previously caused both false positives and false negatives.

This affects noPrecisionLoss and noConstantMathMinMaxClamp.
#8210 7b44e9e Thanks @Netail! - Corrected rule source reference. biome migrate eslint should do a bit better detecting rules in your eslint configurations.
#8213 e430555 Thanks @ruidosujeira! - Fixed #8209: Recognized formatting capability when either range or on-type formatting is supported, not only full-file formatting. This ensures editors and the language server correctly detect formatting support in files like JSONC.
#8202 6f49d95 Thanks @hirokiokada77! - Fixed #8079: Properly handle name and value metavariables for JsxAttribute GritQL queries.

The following biome search command no longer throws an error:
```
1
biome search 'JsxAttribute($name, $value) as $attr where { $name <: "style" }'
```
#8276 f7e836f Thanks @hirokiokada77! - Added the noProto rule, which disallows the use of the __proto__ property for getting or setting the prototype of an object.

Invalid:
```
1
obj.__proto__ = a;
2
const b = obj.__proto__;
```
Valid:
```
1
const a = Object.getPrototypeOf(obj);
2
Object.setPrototypeOf(obj, b);
```

2.3.9 Latest

Patch Changes

#8232 84c9e08 Thanks @ruidosujeira! - Added the nursery rule noScriptUrl.

This rule disallows the use of javascript: URLs, which are considered a form of eval and can pose security risks such as XSS vulnerabilities.
```
1
<a href="javascript:alert('XSS')">Click me</a>
```
#8341 343dc4d Thanks @arendjr! - Added the nursery rule useAwaitThenable, which enforces that await is only used on Promise values.

Invalid
```
1
await "value";
2

3
const createValue = () => "value";
4
await createValue();
```
Caution

This is a first iteration of the rule, and does not yet detect generic “thenable” values.
#8034 e7e0f6c Thanks @Netail! - Added the nursery rule useRegexpExec. Enforce RegExp#exec over String#match if no global flag is provided.
#8137 d407efb Thanks @denbezrukov! - Reduced the internal memory used by the Biome formatter.
#8281 30b046f Thanks @tylersayshi! - Added the rule useRequiredScripts, which enforces presence of configurable entries in the scripts section of package.json files.

#8290 d74c8bd Thanks @dyc3! - The HTML formatter has been updated to match Prettier 3.7’s behavior for handling <iframe>’s allow attribute.

1
<iframe allow="layout-animations 'none'; unoptimized-images 'none'; oversized-images 'none'; sync-script 'none'; sync-xhr 'none'; unsized-media 'none';"></iframe>
2
<iframe
3
  allow="
4
    layout-animations 'none';
5
    unoptimized-images 'none';
6
    oversized-images 'none';
7
    sync-script 'none';
8
    sync-xhr 'none';
9
    unsized-media 'none';
10
  "
11
></iframe>

#8302 d1d5014 Thanks @mlafeldt! - Fixed #8109: return statements in Astro frontmatter no longer trigger “Illegal return statement” errors when using experimentalFullSupportEnabled.

#8346 f3aee1a Thanks @arendjr! - Fixed #8292: Implement tracking of types of TypeScript constructor parameter properties.

This resolves certain false negatives in noFloatingPromises and other typed rules.

Example

1
class AsyncClass {
2
  async returnsPromise() {
3
    return "value";
4
  }
5
}
6

7
class ShouldBeReported {
8
  constructor(public field: AsyncClass) {}
9
  //          ^^^^^^^^^^^^----------------- Parameter property declaration
10

11
  async shouldBeReported() {
12
    // `noFloatingPromises` will now report the following usage:
13
    this.field.returnsPromise();
14
  }
15
}

#8326 153e3c6 Thanks @ematipico! - Improved the rule noBiomeFirstException. The rule can now inspect if extended configurations already contain the catch-all ** inside files.includes and, if so, the rule suggests removing ** from the user configuration.
#8433 397547a Thanks @dyc3! - Fixed #7920: The CSS parser, with Tailwind directives enabled, will no longer error when you use things like prefix(tw) in @import at rules.
#8378 cc2a62e Thanks @Bertie690! - Clarify diagnostic message for lint/style/useUnifiedTypeSignatures

The rule’s diagnostic message now clearly states that multiple similar overload signatures are hard to read & maintain, as opposed to overload signatures in general.
#8296 9d3ef10 Thanks @dyc3! - biome rage now shows if you have experimental HTML full support enabled.
#8414 09acf2a Thanks @Bertie690! - Updated the documentation & diagnostic message for lint/nursery/noProto, mentioning the reasons for its longstanding deprecation and why more modern alternatives are preferred.

Notably, the rule clearly states that using __proto__ inside object literal definitions is still allowed, being a standard way to set the prototype of a newly created object.
#8445 c3df0e0 Thanks @tt-a1i! - Fix --changed and --staged flags throwing “No such file or directory” error when a file has been deleted or renamed in the working directory. The CLI now filters out files that no longer exist before processing.
#8459 b17d12b Thanks @ruidosujeira! - Fix #8435: resolved false positive in noUnusedVariables for generic type parameters in construct signature type members (new <T>(): T).
#8439 a78774b Thanks @tt-a1i! - Fixed #8011: useConsistentCurlyBraces no longer suggests removing curly braces from JSX expression children containing characters that would cause parsing issues or semantic changes when converted to plain JSX text ({, }, <, >, &).
#8436 a392c06 Thanks @ruidosujeira! - Fixed #8429. Formatter, linter, and assist settings now correctly inherit from global configuration when not explicitly specified in overrides.

Before this fix, when an override specified only one feature (e.g., only linter), other features would be incorrectly disabled instead of inheriting from global settings.

Example configuration that now works correctly:
```
1
{
2
  "formatter": { "enabled": true },
3
  "overrides": [
4
    {
5
      "includes": ["*.vue"],
6
      "linter": { "enabled": false }
7
    }
8
  ]
9
}
```
After this fix, .vue files will have the linter disabled (as specified in the override) but the formatter enabled (inherited from global settings).
#8411 9f1b3b0 Thanks @rriski! - Properly handle name, type_arguments, and attributes slots for JsxOpeningElement and JsxSelfClosingElement GritQL patterns.

The following biome search commands no longer throw errors:
Terminal window
```
1
biome search 'JsxOpeningElement(name = $elem_name) where { $elem_name <: "div" }'
2
biome search 'JsxSelfClosingElement(name = $elem_name) where { $elem_name <: "div" }'
```
#8441 cf37d0d Thanks @tt-a1i! - Fixed #6577: noUselessUndefined no longer reports () => undefined in arrow function expression bodies. Previously, the rule would flag this pattern and suggest replacing it with () => {}, which conflicts with the noEmptyBlockStatements rule.
#8444 8caa7a0 Thanks @tt-a1i! - Fix noUnknownMediaFeatureName false positive for prefers-reduced-transparency media feature. The feature name was misspelled as prefers-reduded-transparency in the keywords list.
#8443 c3fa5a1 Thanks @tt-a1i! - Fix useGenericFontNames false positive when a CSS variable is used as the last value in font-family or font. The rule now correctly ignores cases like font-family: "Noto Serif", var(--serif) and font: 1em Arial, var(--fallback).
#8281 30b046f Thanks @tylersayshi! - Fixed noDuplicateDependencies incorrectly triggering on files like _package.json.
#8315 c7915c4 Thanks @hirokiokada77! - Fixed #5213: The noDoneCallback rule no longer flags false positives when a method is called on a regular variable bound to identifiers such as before, after, beforeEach, and afterEach.
#8398 204844f Thanks @Bertie690! - The default value of the ignoreRestSiblings option for noUnusedVariables’ has been reverted to its prior value of true after an internal refactor accidentally changed it.

The diagnostic message has also been tweaked for readability.
#8242 9694e37 Thanks @dyc3! - Fixed bugs in the HTML parser so that it will flag invalid shorthand syntaxes instead of silently accepting them. For example, <Foo : foo="5" /> is now invalid because there is a space after the :.
#8297 efa694c Thanks @Yonom! - Added support for negative value utilities in useSortedClasses. Negative value utilities such as -ml-2 or -top-4 are now recognized and sorted correctly alongside their positive counterparts.
```
1
// Now detected as unsorted:
2
<div class="-ml-2 p-4 -mt-1" />
3
// Suggested fix:
4
<div class="-mt-1 -ml-2 p-4" />
```
#8335 3710702 Thanks @dibashthapa! - Added the new nursery rule useDestructuring. This rule helps to encourage destructuring from arrays and objects.

For example, the following code triggers because the variable name x matches the property foo.x, making it ideal for object destructuring syntax.
```
1
var x = foo.x;
```
#8383 59b2f9a Thanks @ematipico! - Fixed #7927: noExtraNonNullAssertion incorrectly flagged separate non-null assertions on both sides of an assignment.

The rule now correctly distinguishes between nested non-null assertions (still flagged) and separate non-null assertions on different sides of an assignment (allowed).

Examples

Valid (now allowed)
```
1
arr[0]! ^= arr[1]!;
```
Invalid (still flagged)
```
1
arr[0]!! ^= arr[1];
2
arr[0] ^= arr[1]!!;
```

#8401 382786b Thanks @Bertie690! - useExhaustiveDependencies now correctly validates custom hooks whose dependency arrays come before their callbacks.

Previously, a logical error caused the rule to be unable to detect dependency arrays placed before hook callbacks, producing spurious errors and blocking further diagnostics.

1
{
2
  "linter": {
3
    "rules": {
4
      "correctness": {
5
        "useExhaustiveDependencies": {
6
          "level": "error",
7
          "options": {
8
            "hooks": [
9
              {
10
                "name": "doSomething",
11
                "closureIndex": 2,
12
                "dependenciesIndex": 0
13
              }
14
            ]
15
          }
16
        }
17
      }
18
    }
19
  }
20
}

1
function component() {
2
  let thing = 5;
3
  // The rule will now correctly recognize `thing` as being specified
4
  // instead of erroring due to "missing" dependency arrays
5
  doSomething([thing], "blah", () => {
6
    console.log(thing);
7
  });
8
}

The rule documentation & diagnostic messages have also been reworked for improved clarity.

#8365 8f36051 Thanks @JacquesLeupin! - Fixed #8360: GritQL plugins defined in child configurations with extends: "//" now work correctly.
#8306 8de2774 Thanks @dibashthapa! - Fixed #8288: Fixed the issue with false positive errors

This new change will ignore attribute and only show diagnostics for JSX Expressions

For example

Valid:
```
1
<Something checked={isOpen && items.length} />
```
Invalid:
```
1
const Component = () => {
2
  return isOpen && items.length;
3
};
```
#8356 f9673fc Thanks @ematipico! - Fixed #7917, where Biome removed the styles contained in a <style lang="scss">, when experimentalFullSupportEnabled is enabled.
#8371 d71924e Thanks @ematipico! - Fixed #7343, where Biome failed to resolve extended configurations from parent directories using relative paths.
#8404 6a221f9 Thanks @fireairforce! - Fixed #7826, where a class member named async will not cause the parse error.
#8249 893e36c Thanks @cormacrelf! - Addressed #7538. Reduced the volume of logging from the LSP server.

Use biome clean to remove large logs.

#8303 db2c65b Thanks @hirokiokada77! - Fixed #8300: noUnusedImports now detects JSDoc tags on object properties.

1
import type LinkOnObjectProperty from "mod";
2

3
const testLinkOnObjectProperty = {
4
  /**
5
   * {@link LinkOnObjectProperty}
6
   */
7
  property: 0,
8
};

#8328 9cf2332 Thanks @Netail! - Corrected rule source reference. biome migrate eslint should do a bit better detecting rules in your eslint configurations.
#8403 c96dcf2 Thanks @dyc3! - Fixed #8340: noUnknownProperty will no longer flag anything in @plugin when the parser option tailwindDirectives is enabled
#8284 4976d1b Thanks @denbezrukov! - Improved the performance of the Biome Formatter by enabling the internal source maps only when needed.
#8260 a226b28 Thanks @ho991217! - Fixed biome-vscode#817: Biome now updates documents when the textDocument/didSave notification is received.
#8183 b064786 Thanks @hornta! - Fixed #8179: The useConsistentArrowReturn rule now correctly handles multiline expressions in its autofix when the style option is set to "always".

Previously, the autofix would incorrectly place a newline after the return keyword, causing unexpected behavior.

Example:
```
1
const foo = (l) => l.split("\n");
```
Now correctly autofixes to:
```
1
const foo = (l) => {
2
   return
3
   l.split('\n');
4
   return l.split('\n');
5
}
```
#8382 7409cba Thanks @fireairforce! - Fixed #8338: Ignored the noUnknownTypeSelector check when the root selector is used under View Transition pseudo-elements.

Example
```
1
::view-transition-old(root),
2
::view-transition-new(root) {
3
  z-index: 1;
4
}
```
#7513 e039f3b Thanks @AsherDe! - Added the nursery rule noVueSetupPropsReactivityLoss.

This new rule disallows usages that cause the reactivity of props passed to the setup function to be lost.

Invalid code example:
```
1
export default {
2
  setup({ count }) {
3
    // `count` is no longer reactive here.
4
    return () => h("div", count);
5
  },
6
};
```

All versions since 2.3.2

2.3.2

Patch Changes

2.3.3

Patch Changes

2.3.4

Patch Changes

2.3.5

Patch Changes

2.3.6

Patch Changes

Invalid

Valid

2.3.7

Patch Changes

2.3.8

Patch Changes

2.3.9 Latest

Patch Changes

Invalid

Caution

Example

Examples

Valid (now allowed)

Invalid (still flagged)