1.5.3 (2024-01-22)

LSP

Bug fixes

• Fix #1584. Ensure the LSP only registers the formatter once. Contributed by @nhedger

• Fix #1589. Fix invalid formatting of own line comments when they were at the end of an import/export list. Contributed by @spanishpear

Configuration

Bug fixes

• Override correctly the recommended preset (#1349).

  Previously, if unspecified, Biome turned on the recommended preset in overrides. This resulted in reporting diagnostics with a severity level set to off. This in turn caused Biome to fail.

  Now Biome won't switch on the recommended preset in overrides unless told to do so.

  Contributed by @Conaclos

• Don't format ignored files that are well-known JSONC files when files.ignoreUnknown is enabled (#1607).

  Previously, Biome always formatted files that are known to be JSONC files (e.g. .eslintrc) when files.ignoreUnknown was enabled.

  Contributed by @Conaclos

Formatter

New features

• Add option json.formatter.trailingCommas, to provide a better control over the trailing comma in JSON/JSONC files. Its default value is "none".

Bug fixes

• Fix #1178, where the line ending option wasn't correctly applied. Contributed by @ematipico
• Fix #1571. Fix invalid formatting of nested multiline comments. Contributed by @ah-yu

Linter

Bug fixes

Fix #1575. noArrayIndexKey now captures array index value inside template literals and with string concatination. Contributed by @vasucp1207

• Linter rules that inspect regexes now handle multibyte characters correctly (#1522).

  Previously, noMisleadingCharacterClass, noMultipleSpacesInRegularExpressionLiterals, and noEmptyCharacterClassInRegex made Biome errors on multi-bytes characters. Multibyte characters are now handled correctly.

  The following code no longer raises an internal error:

  // Cyrillic characters
  /[\u200E\u2066-\u2069]/gu;
  

  Contributed by @Conaclos

• useExhaustiveDependencies no longer made Biome errors in code TypeScript import equal declarations (#1194). Contributed by @Conaclos

• Fix typo in the diagnostic of noNodejsModules. Contributed by @huseeiin

Parser

Bug fixes

• Accept the const modifier for type parameter in method type signature (#1624).

  The following code is now correctly parsed:

  type Foo = {
    <const T>();
    method<const T>();
  };
  

  Contributed by @magic-akari

• Correctly parse type arguments in expression(#1184).

  The following code is now correctly parsed in typescript:

  0 < (0 >= 1);
  

  Contributed by @ah-yu

Website

New

• Add a page that maps the Biome rule to its source. Contributed by @ematipico

Fixes

• Generate Open Graph images based on the linked page. Contributed by @ematipico

• Fix examples of the git hook page. Contributed by @9renpoto, @lmauromb, and @Conaclos

• Fix dead and erroneous hyperlinks. Contributed by @Sec-ant and Conaclos

1.5.2 (2024-01-15)

CLI

Bug fixes

• Fix #1512 by skipping verbose diagnostics from the count. Contributed by @ematipico

• Correctly handle cascading include and ignore.

  Previously Biome incorrectly included files that were included at tool level and ignored at global level. In the following example, file.js was formatted when it should have been ignored. Now, Biome correctly ignores the directory ./src/sub/.

  ❯ tree src
    src
    └── sub
        └── file.js
  
  ❯ cat biome.json
    {
      "files": { "ignore": ["./src/sub/"] },
      "formatter": { "include": ["./src"] }
    }
  

  Contributed by @Conaclos

• Don't emit verbose warnings when a protected file is ignored.

  Some files, such as package.json and tsconfig.json, are protected. Biome emits a verbose warning when it encounters a protected file.

  Previously, Biome emitted this verbose warning even if the file was ignored by the configuration. Now, it doesn't emit verbose warnings for protected files that are ignored.

  Contributed by @Conaclos

• overrides no longer affect which files are ignored. Contributed by @Conaclos

• The file biome.json can't be ignored anymore. Contributed by @ematipico

• Fix #1541 where the content of protected files wasn't returned to stdout. Contributed by @ematipico

• Don't handle CSS files, the formatter isn't ready yet. Contributed by @ematipico

Configuration

Bug fixes

• Fix 1440, a case where extends and overrides weren't correctly emitting the final configuration. Contributed by @arendjr

• Correctly handle include when ignore is set (#1468). Contributed by @Conaclos

  Previously, Biome ignored include if ignore was set. Now, Biome check both include and ignore. A file is processed if it is included and not ignored. If include is not set all files are considered included.

Formatter

Bug fixes

• Fix placement of comments before * token in generator methods with decorators. #1537 Contributed by @ah-yu

• Fix #1406. Ensure comments before the async keyword are placed before it. Contributed by @ah-yu

• Fix #1172. Fix placement of line comment after function expression parentheses, they are now attached to first statement in body. Contributed by @kalleep

• Fix #1511 that made the JavaScript formatter crash. Contributed @Conaclos

Linter

Enhancements

• Add an unsafe code fix for noConsoleLog. Contributed by @vasucp1207

• useArrowFunction no longer reports function in extends clauses or in a new expression. Contributed by @Conaclos

  These cases require the presence of a prototype.

• Add dependency variable names on error message when useExhaustiveDependencies rule shows errors. Contributed by @mehm8128

Bug fixes

• The fix of useArrowFunction now adds parentheses around the arrow function in more cases where it is needed (#1524).

  A function expression doesn't need parentheses in most expressions where it can appear. This is not the case with the arrow function. We previously added parentheses when the function appears in a call or member expression. We now add parentheses in binary-like expressions and other cases where they are needed, hopefully covering all cases.

  Previously:

  - f = f ?? function() {};
  + f = f ?? () => {};
  

  Now:

  - f = f ?? function() {};
  + f = f ?? (() => {});
  

  Contributed by @Conaclos

• Fix #1514. Fix autofix suggestion to avoid the syntax error in no_useless_fragments. Contributed by @togami2864

1.5.1 (2024-01-10)

CLI

Bug fixes

• The diagnostics files/missingHandler are now shown only when the option --verbose is passed. Contributed by @ematipico
• The diagnostics for protected files are now shown only when the option --verbose is passed. Contributed by @ematipico
• Fix #1465, by taking in consideration the workspace folder when matching a pattern. Contributed by @ematipico
• Fix #1465, by correctly process globs that contain file names. Contributed by @ematipico

Formatter

Bug fixes

• Fix #1170. Fix placement of comments inside default switch clause. Now all line comments that have a preceding node will keep their position. Contributed by @kalleep

Linter

Bug fixes

Fix #1335. noUselessFragments now ignores code action on component props when the fragment is empty. Contributed by @vasucp1207

• useConsistentArrayType was accidentally placed in the style rule group instead of the nursery group. It is now correctly placed under nursery.

Fix #1483. useConsistentArrayType now correctly handles its option. Contributed by @Conaclos

Fix #1502. useArrowFunction now correctly handle functions that return a (comma) sequence expression. Contributed by @Conaclos

Previously the rule made an erroneous suggestion:

- f(function() { return 0, 1; }, "");
+ f(() => 0, 1, "")

Now, the rule wraps any comma sequence between parentheses:

- f(function() { return 0, 1; }, "");
+ f(() => (0, 1), "")

Fix #1473: useHookAtTopLevel now correctly handles React components and hooks that are nested inside other functions. Contributed by @arendjr

1.5.0 (2024-01-08)

Biome now scores 97% compatibility with Prettier and features more than 180 linter rules.

Analyzer

CLI

New features

• Biome now shows a diagnostic when it encounters a protected file. Contributed by @ematipico

• The command biome migrate now updates the $schema if there's an outdated version.

• The CLI now takes in consideration the .gitignore in the home directory of the user, if it exists. Contributed by @ematipico

• The biome ci command is now able to print GitHub Workflow Commands when there are diagnostics in our code. Contributed by @nikeee This might require setting the proper permissions on your GitHub action:

  permissions:
    pull-requests: write
  

• The commands format, lint, check and ci now accept two new arguments: --changed and --since. Use these options with the VCS integration is enabled to process only the files that were changed. Contributed by @simonxabris

  biome format --write --changed
  

• Introduced a new command called biome explain, which has the capability to display documentation for lint rules. Contributed by @kalleep

• You can use the command biome explain to print the documentation of lint rules. Contributed by @kalleep

  biome explain noDebugger
  biome explain useAltText
  

• You can use the command biome explain to print the directory where daemon logs are stored. Contributed by @ematipico

  biome explain daemon-logs
  

• Removed the hard coded limit of 200 printable diagnostics. Contributed by @ematipico

Bug fixes

• Fix #1247, Biome now prints a warning diagnostic if it encounters files that can't handle. Contributed by @ematipico

  You can ignore unknown file types using the files.ignoreUnknown configuration in biome.json:

  {
    "files": {
      "ignoreUnknown": true
    }
  }
  

  Or the --files-ignore-unknown CLI option:

  biome format --files-ignore-unknown=true --write .
  

• Fix #709 and #805 by correctly parsing .gitignore files. Contributed by @ematipico

• Fix #1117 by correctly respecting the matching. Contributed by @ematipico

• Fix #691 and #1190, by correctly apply the configuration when computing overrides configuration. Contributed by @ematipico

Configuration

New features

• Users can specify git ignore patterns inside ignore and include properties, for example it's possible to allow list globs of files using the ! character:

  {
    "files": {
      "ignore": [
        "node_modules/**",
        "!**/dist/**" // this is now accepted and allow files inside the `dist` folder
      ]
    }
  }
  

Editors

New features

• The LSP registers formatting without the need of using dynamic capabilities from the client.

  This brings formatting services to the editors that don't support or have limited support for dynamic capabilities.

Formatter

Bug fixes

• Fix #1169. Account for escaped strings when computing layout for assignments. Contributed by @kalleep

• Fix #851. Allow regular function expressions to group and break as call arguments, just like arrow function expressions. #1003 Contributed by @faultyserver

• Fix #914. Only parenthesize type-casted function expressions as default exports. #1023 Contributed by @faultyserver

• Fix #1112. Break block bodies in case clauses onto their own lines and preserve trailing fallthrough comments. #1035 Contributed by @faultyserver

• Fix RemoveSoftLinesBuffer behavior to also removed conditional expanded content, ensuring no accidental, unused line breaks are included #1032 Contributed by @faultyserver

• Fix #1024. Allow JSX expressions to nestle in arrow chains #1033 Contributed by @faultyserver

• Fix incorrect breaking on the left side of assignments by always using fluid assignment. #1021 Contributed by @faultyserver

• Fix breaking strategy for nested object patterns in function parameters #1054 Contributed by @faultyserver

• Fix over-indention of arrow chain expressions by simplifying the way each chain is grouped #1036, #1136, and #1162 Contributed by @faultyserver.

• Fix "simple" checks for calls and member expressions to correctly handle array accesses, complex arguments to single-argument function calls, and multiple-argument function calls. #1057 Contributed by @faultyserver

• Fix text wrapping and empty line handling for JSX Text elements to match Prettier's behavior. #1075 Contributed by @faultyserver

• Fix leading comments in concisely-printed arrays to prevent unwanted line breaks. #1135 Contributed by @faultyserver

• Fix best_fitting and interned elements preventing expansion propagation from sibling elements. #1141 Contributed by @faultyserver

• Fix heuristic for grouping function parameters when type parameters with constraints are present. #1153. Contributed by @faultyserver.

• Fix binary-ish and type annotation handling for grouping call arguments in function expressions and call signatures. #1152 and #1160 Contributed by @faultyserver

• Fix handling of nestled JSDoc comments to preserve behavior for overloads. #1195 Contributed by @faultyserver

• Fix #1208. Fix extraction of inner types when checking for simple type annotations in call arguments. #1195 Contributed by @faultyserver

• Fix #1220. Avoid duplicating comments in type unions for mapped, empty object, and empty tuple types. #1240 Contributed by @faultyserver

• Fix #1356. Ensure if_group_fits_on_line content is always written in RemoveSoftLinesBuffers. #1357 Contributed by @faultyserver

• Fix #1171. Correctly format empty statement with comment inside arrow body when used as single argument in call expression. Contributed by @kalleep

• Fix #1106. Fix invalid formatting of single bindings when Arrow Parentheses is set to "AsNeeded" and the expression breaks over multiple lines. #1449 Contributed by @faultyserver

JavaScript APIs

Linter

Promoted rules

New rules are incubated in the nursery group. Once stable, we promote them to a stable group. The following rules are promoted:

• a11y/noAriaHiddenOnFocusable
• a11y/useValidAriaRole
• complexity/useRegexLiterals
• suspicious/noImplicitAnyLet
• style/noDefaultExport

New features

• Add useExportType that enforces the use of type-only exports for types. Contributed by @Conaclos

    interface A {}
    interface B {}
    class C {}
  
  - export type { A, C }
  + export { type A, C }
  
  - export { type B }
  + export type { B }
  

• Add useImportType that enforces the use of type-only imports for types. Contributed by @Conaclos

  - import { A, B } from "./mod.js";
  + import { type A, B } from "mod";
    let a: A;
    const b: B = new B();
  

  Also, the rule groups type-only imports:

  - import { type A, type B } from "./mod.js";
  + import type { A, B } from "./mod.js";
  

• Add useFilenamingConvention, that enforces naming conventions for JavaScript and TypeScript filenames. Contributed by @Conaclos

  By default, the rule requires that a filename be in camelCase, kebab-case, snake_case, or matches the name of an export in the file. The rule provides options to restrict the allowed cases.

• Add useNodejsImportProtocol that enforces the use of the node: protocol when importing Node.js modules. Contributed by @2-NOW, @vasucp1207, and @Conaclos

  - import fs from "fs";
  + import fs from "node:fs";
  

• Add useNumberNamespace that enforces the use of the Number properties instead of the global ones.

  - parseInt;
  + Number.parseInt;
  - - Infinity;
  + Number.NEGATIVE_INFINITY;
  

• Add useShorthandFunctionType that enforces using function types instead of object type with call signatures. Contributed by @emab, @ImBIOS, and @seitarof

  - interface Example {
  -   (): string;
  - }
  + type Example = () => string
  

- Add [noNodejsModules](https://biomejs.dev/linter/rules/no-nodejs-modules), that disallows the use of _Node.js_ modules. Contributed by @anonrig, @ematipico, and @Conaclos

- Add [noInvalidUseBeforeDeclaration](https://biomejs.dev/linter/rules/no-invalid-use-before-declaration) that reports variables and function parameters used before their declaration. Contributed by @Conaclos

  ```js
  function f() {
    console.log(c); // Use of `c` before its declaration.
    const c = 0;
  }

• Add useConsistentArrayType that enforces the use of a consistent syntax for array types. Contributed by @eryue0220

  This rule will replace useShorthandArrayType. It provides an option to choose between the shorthand or the generic syntax.

• Add noEmptyTypeParameters that ensures that any type parameter list has at least one type parameter. Contributed by @togami2864

  This will report the following empty type parameter lists:

  interface Foo<> {}
  //           ^^
  type Bar<> = {};
  //      ^^
  

• Add noGlobalEval that reports any use of the global eval. Contributed by @you-5805

• Add noGlobalAssign that reports assignment to global variables. Contributed by @chansuke

  Object = {}; // report assignment to `Object`.
  

• Add noMisleadingCharacterClass that disallows characters made with multiple code points in character class. Contributed by @togami2864

• Add noThenProperty that disallows the use of then as property name. Adding a then property makes an object thenable that can lead to errors with Promises. Contributed by @togami2864

• Add noUselessTernary that disallows conditional expressions ( ternaries) when simpler alternatives exist.

  var a = x ? true : true; // this could be simplified to `x`
  

Enhancements

• noEmptyInterface ignores empty interfaces that extend a type. Address #959 and #1157. Contributed by @Conaclos

  This allows supporting interface augmentation in external modules as demonstrated in the following example:

  interface Extension {
    metadata: unknown;
  }
  
  declare module "@external/module" {
    // Empty interface that extends a type.
    export interface ExistingInterface extends Extension {}
  }
  

• Preserve more comments in the code fix of useExponentiationOperator. Contributed by @Conaclos

  The rule now preserves comments that follow the (optional) trailing comma.

  For example, the rule now suggests the following code fix:

  - Math.pow(
  -    a, // a
  -    2, // 2
  -  );
  +
  +    a ** // a
  +    2 // 2
  +
  

• <svg> element is now considered as a non-interactive HTML element (#1095). Contributed by @chansuke

  This affects the following rules:

  • noAriaHiddenOnFocusable
  • noInteractiveElementToNoninteractiveRole
  • noNoninteractiveElementToInteractiveRole
  • noNoninteractiveTabindex
  • useAriaActivedescendantWithTabindex

• noMultipleSpacesInRegularExpressionLiterals has a safe code fix. Contributed by @Conaclos

• useArrowFunction ignores expressions that use new.target. Contributed by @Conaclos

• noForEach now reports only calls that use a callback with 0 or 1 parameter. Address #547. Contributed by @Conaclos

Bug fixes

Fix #1061. noRedeclare no longer reports overloads of export default function. Contributed by @Conaclos

The following code is no longer reported:

export default function(a: boolean): boolean;
export default function(a: number): number;
export default function(a: number | boolean): number | boolean {
  return a;
}

Fix #651, useExhaustiveDependencies no longer reports out of scope dependencies. Contributed by @kalleep

The following code is no longer reported:

let outer = false;

const Component = ({}) => {
  useEffect(() => {
    outer = true;
  }, []);
}

Fix #1191. noUselessElse now preserve comments of the else clause. Contributed by @Conaclos

For example, the rule suggested the following fix:

  function f(x) {
    if (x <0) {
      return 0;
    }
-   // Comment
-   else {
      return x;
-   }
  }

Now the rule suggests a fix that preserves the comment of the else clause:

  function f(x) {
    if (x <0) {
      return 0;
    }
    // Comment
-   else {
      return x;
-   }
  }

Fix #1383. noConfusingVoidType now accepts the void type in type parameter lists.

The rule no longer reports the following code:

f<void>();

Fix #728. useSingleVarDeclarator no longer outputs invalid code. Contributed by @Conaclos

Fix #1167. useValidAriaProps no longer reports aria-atomic as invalid. Contributed by @unvalley

Fix #1192. useTemplate now correctly handles parenthesized expressions and respects type coercions. Contributed by @n-gude

These cases are now properly handled:

"a" + (1 + 2) // `a${1 + 2}`

1 + (2 + "a") // `${1}${2}a`

Fix #1456. useTemplate now reports expressions with an interpolated template literal and non-string expressions. Contributed by @n-gude

The following code is now reported:

`a${1}` + 2;

Fix #1436. useArrowFunction now applies a correct fix when a function expression is used in a call expression or a member access. Contributed by @Conaclos

For example, the rule proposed the following fix:

- const called = function() {}();
+ const called = () => {}();

It now proposes a fix that adds the needed parentheses:

- const called = function() {}();
+ const called = (() => {})();

Fix #696. useHookAtTopLevel now correctly detects early returns before the calls to the hook.

• The code fix of noUselessTypeCOnstraint now adds a trailing comma when needed to disambiguate a type parameter list from a JSX element. COntributed by @Conaclos

Fix #578. useExhaustiveDependencies now correctly recognizes hooks namespaced under the React namespace. Contributed by @XiNiHa

Fix #910. noSvgWithoutTitle now ignores <svg> element with aria-hidden="true". COntributed by @vasucp1207

Parser

BREAKING CHANGES

• The representation of imports has been simplified. Contributed by @Conaclos

  The new representation is closer to the ECMAScript standard. It provides a single way of representing a namespace import such as import * as ns from "". It rules out some invalid states that was previously representable. For example, it is no longer possible to represent a combined import with a type qualifier such as import type D, { N } from "".

  See #1163 for more details.

New features

• Imports and exports with both an import attribute and a type qualifier are now reported as parse errors.

  import type A from "mod" with { type: "json" };
  //     ^^^^              ^^^^^^^^^^^^^^^^^^^^^
  //     parse error
  

Bug fixes

• Fix #1077 where parenthesized identifiers in conditional expression were being parsed as arrow expressions. Contributed by @kalleep

  These cases are now properly parsed:

  JavaScript:

    a ? (b) : a => {};
  

  TypeScript:

    a ? (b) : a => {};
  

  JSX:

    bar ? (foo) : (<a>{() => {}}</a>);
  

• Allow empty type parameter lists for interfaces and type aliases (#1237). COntributed by @togami2864

  TypeScript allows interface declarations and type aliases to have empty type parameter lists. Previously Biome didn't handle this edge case. Now, it correctly parses this syntax:

  interface Foo<> {}
  type Bar<> = {};
  

Crates

BREAKING CHANGES

• Rename the biome_js_unicode_table crate to biome_unicode_table (#1302). COntributed by @chansuke