All versions since 2.3.8

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 2.3.8

2.3.8

Patch Changes

2.3.9 Latest

Patch Changes

Invalid

Caution

Example

Examples

Valid (now allowed)

Invalid (still flagged)