Changelog

Biome changelog

This project follows Semantic Versioning. Due to the nature of Biome as a toolchain, it can be unclear what changes are considered major, minor, or patch. Read our guidelines to categorize a change.

New entries must be placed in a section entitled Unreleased. Read our guidelines for writing a good changelog entry.

1.7.3 (2024-05-06)

CLI

Bug fixes

The stdin-file-path option now works correctly for Astro/Svelte/Vue files (#2686)

Fix #2225 where lint output become empty for Vue files.

Contributed by @tasshi-me
biome migrate eslint now correctly resolve @scope/eslint-config (#2705). Contributed by @Conaclos

Formatter

Linter

New features

Add nursery/useExplicitLengthCheck.

Bug fixes

noBlankTarget no longer hangs when applying a code fix (#2675).

Previously, the following code made Biome hangs when applying a code fix.
```
<a href="https://example.com" rel="" target="_blank"></a>
```
Contributed by @Conaclos
noRedeclare no longer panics on conditional type (#2659).

This is a regression introduced by #2394. This regression makes noRedeclare panics on every conditional types with infer bindings.

Contributed by @Conaclos
noUnusedLabels and noConfusingLabels now ignore svelte reactive statements (#2571).

The rules now ignore reactive Svelte blocks in Svelte components.
```
<script>
$: { /* reactive block */ }
</script>
```
Contributed by @Conaclos
useExportType no longer removes leading comments (#2685).

Previously, useExportType removed leading comments when it factorized the type qualifier. It now provides a code fix that preserves the leading comments:
```
export {
export type {
  /**leading comment*/
  type T
  T
}
```
Contributed by @Conaclos
useJsxKeyInIterable no longer reports false positive when iterating on non-jsx items (#2590).

The following snipet of code no longer triggers the rule:
```
<>{data.reduce((total, next) => total + next, 0)}</>
```
Contributed by @dyc3
Fix typo by renaming useConsistentBuiltinInstatiation to useConsistentBuiltinInstantiation Contributed by @minht11

1.7.2 (2024-04-30)

Analyzer

Bug fixes

Import sorting now ignores side effect imports (#817).

A side effect import consists now in its own group. This ensures that side effect imports are not reordered.

Here is an example of how imports are now sorted:
```
import "z"
import { D } from "d";
import { C } from "c";
import { D } from "d";
import "y"
import "x"
import { B } from "b";
import { A } from "a";
import { B } from "b";
import "w"
```
Contributed by @Conaclos
Import sorting now adds spaces where needed (#1665) Contributed by @Conaclos

CLI

Bug fixes

biome migrate eslint now handles cyclic references.

Some plugins and configurations export objects with cyclic references. This causes biome migrate eslint to fail or ignore them. These edge cases are now handled correctly.

Contributed by @Conaclos

Formatter

Bug fixes

Correctly handle placement of comments inside named import clauses. #2566. Contributed by @ah-yu

Linter

New features

Add nursery/noReactSpecificProps. Contributed by @marvin-j97
Add noUselessUndefinedInitialization. Contributed by @lutaok
Add nursery/useArrayLiterals. Contributed by @Kazuhiro-Mimaki
Add nursery/useConsistentBuiltinInstatiation. Contributed by @minht11
Add nursery/useDefaultSwitchClause. Contributed by @michellocana

Bug fixes

noDuplicateJsonKeys no longer crashes when a JSON file contains an unterminated string (#2357). Contributed by @Conaclos
noRedeclare now reports redeclarations of parameters in a functions body (#2394).

The rule was unable to detect redeclarations of a parameter or a type parameter in the function body. The following two redeclarations are now reported:
```
function f<T>(a) {
  type T = number; // redeclaration
  const a = 0; // redeclaration
}
```
Contributed by @Conaclos
noRedeclare no longer reports overloads in object types (#2608).

The rule no longer report redeclarations in the following code:
```
type Overloads = {
  ({ a }: { a: number }): number,
  ({ a }: { a: string }): string,
};
```
Contributed by @Conaclos
noRedeclare now merge default function export declarations and types (#2372).

The following code is no longer reported as a redeclaration:
```
interface Foo {}
export default function Foo() {}
```
Contributed by @Conaclos
noUndeclaredVariables no longer reports variable-only and type-only exports (#2637). Contributed by @Conaclos
noUnusedVariables no longer crash Biome when encountering a malformed conditional type (#1695). Contributed by @Conaclos
useConst now ignores a variable that is read before its assignment.

Previously, the rule reported the following example:
```
let x;
x; // read
x = 0; // write
```
It is now correctly ignored.

Contributed by @Conaclos
useShorthandFunctionType now suggests correct code fixes when parentheses are required (#2595).

Previously, the rule didn’t add parentheses when they were needed. It now adds parentheses when the function signature is inside an array, a union, or an intersection.
```
type Union = { (): number } | string;
type Union = (() => number) | string;
```
Contributed by @Conaclos
useTemplate now correctly escapes strings (#2580).

Previously, the rule didn’t correctly escape characters preceded by an escaped character.

Contributed by @Conaclos
noMisplacedAssertion now allow these matchers
- expect.any()
- expect.anything()
- expect.closeTo
- expect.arrayContaining
- expect.objectContaining
- expect.stringContaining
- expect.stringMatching
- expect.extend
- expect.addEqualityTesters
- expect.addSnapshotSerializer
Contributed by @fujiyamaorange

Parser

Bug fixes

The language parsers no longer panic on unterminated strings followed by a newline and a space (#2606, #2410).

The following example is now parsed without making Biome panics:
```
"
 "
```
Contributed by @Conaclos

1.7.1 (2024-04-22)

Editors

Bug fixes

Fix #2403 by printing the errors in the client console. Contributed by @ematipico

Formatter

Bug fixes

Add parentheses for the return expression that has leading multiline comments. #2504. Contributed by @ah-yu
Correctly format dangling comments of continue statements. #2555. Contributed by @ah-yu
Prevent comments from being eaten by the formatter #2578. Now the comments won’t be eaten for the following code:
```
console.log((a,b/* comment */));
```
Contributed by @ah-yu
Correctly format nested union type to avoid reformatting issue. #2628. Contributed by @ah-yu

Linter

Bug fixes

Fix case where jsxRuntime wasn’t being respected by useImportType rule (#2473).Contributed by @arendjr
Fix #2460, where the rule noUselessFragments was crashing the linter in some cases. Now cases like these are correctly handled:
```
callFunction(<>{bar}</>)
```
Contributed by @ematipico
Fix #2366, where noDuplicateJsonKeys incorrectly computed the kes to highlight. Contributed by @ematipico

Enhancements

The rule noMisplacedAssertions now considers valid calling expect inside waitFor:

import { waitFor } from '@testing-library/react';

await waitFor(() => {
  expect(111).toBe(222);
});

Contributed by @ematipico

1.7.0 (2024-04-15)

Analyzer

Bug fixes

Now Biome can detect the script language in Svelte and Vue script blocks more reliably (#2245). Contributed by @Sec-ant
useExhaustiveDependencies no longer reports recursive calls as missing dependencies (#2361). Contributed by @arendjr
useExhaustiveDependencies correctly reports missing dependencies declared using function declarations (#2362). Contributed by @arendjr
Biome now can handle .svelte and .vue files with CRLF as the end-of-line sequence. Contributed by @Sec-ant
noMisplacedAssertion no longer reports method calls by describe, test, it objects (e.g. test.each([])()) (#2443). Contributed by @unvalley.

Biome now can handle .vue files with generic components (#2456).

<script generic="T extends Record<string, any>" lang="ts" setup>
//...
</script>

Contributed by @Sec-ant

Enhancements

Complete the well-known file lists for JSON-like files. Trailing commas are allowed in .jsonc files by default. Some well-known files like tsconfig.json and .babelrc don’t use the .jsonc extension but still allow comments and trailing commas. While others, such as .eslintrc.json, only allow comments. Biome is able to identify these files and adjusts the json.parser.allowTrailingCommas option accordingly to ensure they are correctly parsed. Contributed by @Sec-ant
Fix dedent logic inconsistent with prettier where the indent-style is space and the indent-width is not 2. Contributed by @mdm317

CLI

New features

Add a command to migrate from ESLint

biome migrate eslint allows you to migrate an ESLint configuration to Biome. The command supports legacy ESLint configurations and new flat ESLint configurations. Legacy ESLint configurations using the YAML format are not supported.

When loading a legacy ESLint configuration, Biome resolves the extends field. It resolves both shared configurations and plugin presets! To do this, it invokes Node.js.

Biome relies on the metadata of its rules to determine the equivalent rule of an ESLint rule. A Biome rule is either inspired or roughly identical to an ESLint rules. By default, inspired and nursery rules are excluded from the migration. You can use the CLI flags --include-inspired and --include-nursery to migrate them as well.

Note that this is a best-effort approach. You are not guaranteed to get the same behavior as ESLint.

Given the following ESLint configuration:
```
{
      "ignore_patterns": ["**/*.test.js"],
      "globals": { "var2": "readonly" },
      "rules": {
          "eqeqeq": "error"
      },
      "overrides": [{
          "files": ["lib/*.js"],
          "rules": {
            "default-param-last": "off"
          }
      }]
}
```
biome migrate eslint --write changes the Biome configuration as follows:
```
{
  "linter": {
    "rules": {
      "recommended": false,
      "suspicious": {
        "noDoubleEquals": "error"
      }
    }
  },
  "javascript": { "globals": ["var2"] },
  "overrides": [{
    "include": ["lib/*.js"],
    "linter": {
      "rules": {
        "style": {
          "useDefaultParameterLast": "off"
        }
      }
    }
  }]
}
```
Also, if the working directory contains .eslintignore, then Biome migrates the glob patterns. Nested .eslintignore in subdirectories and negated glob patterns are not supported.

If you find any issue, please don’t hesitate to report them.

Contributed by @Conaclos
Added two new options to customise the emitted output of the CLI: --reporter=json and --reporter=json-pretty. With --reporter=json, the diagnostics and the summary will be printed in the terminal in JSON format. With --reporter=json-pretty, you can print the same information, but formatted using the same options of your configuration.

NOTE: the shape of the JSON is considered experimental, and the shape of the JSON might change in the future.

Example of output when running `biome format` command
```json { "summary": { "changed": 0, "unchanged": 1, "errors": 1, "warnings": 0, "skipped": 0, "suggestedFixesSkipped": 0, "diagnosticsNotPrinted": 0 }, "diagnostics": [ { "category": "format", "severity": "error", "description": "Formatter would have printed the following content:", "message": [ { "elements": [], "content": "Formatter would have printed the following content:" } ], "advices": { "advices": [ { "diff": { "dictionary": " statement();\n", "ops": [ { "diffOp": { "delete": { "range": [0, 2] } } }, { "diffOp": { "equal": { "range": [2, 12] } } }, { "diffOp": { "delete": { "range": [0, 2] } } }, { "diffOp": { "equal": { "range": [12, 13] } } }, { "diffOp": { "delete": { "range": [0, 2] } } }, { "diffOp": { "insert": { "range": [13, 15] } } } ] } } ] }, "verboseAdvices": { "advices": [] }, "location": { "path": { "file": "format.js" }, "span": null, "sourceCode": null }, "tags": [], "source": null } ], "command": "format" } ```
Added new --staged flag to the check, format and lint subcommands.

This new option allows users to apply the command only to the files that are staged (the ones that will be committed), which can be very useful to simplify writing git hook scripts such as pre-commit. Contributed by @castarco

Enhancements

Improve support of .prettierignore when migrating from Prettier

Now, Biome translates most of the glob patterns in .prettierignore to the equivalent Biome ignore pattern. Only negated glob patterns are not supported.

Contributed by @Conaclos
Support JavaScript configuration files when migrating from Prettier

biome migrate prettier is now able to migrate Prettier configuration files ending with js, mjs, or cjs extensions. To do this, Biome invokes Node.js.

Also, embedded Prettier configurations in package.json are now supported.

Contributed by @Conaclos
Support overrides field in Prettier configuration files when migrating from Prettier. Contributed by @Conaclos
Support passing a file path to the --config-path flag or the BIOME_CONFIG_PATH environment variable.

Now you can pass a .json/.jsonc file path with any filename to the --config-path flag or the BIOME_CONFIG_PATH environment variable. This will disable the configuration auto-resolution and Biome will try to read the configuration from the said file path (#2265).
Terminal window
```
biome format --config-path=../biome.json ./src
```
Contributed by @Sec-ant

Bug fixes

Biome now tags the diagnostics emitted by organizeImports and formatter with correct severity levels, so they will be properly filtered by the flag --diagnostic-level (#2288). Contributed by @Sec-ant
Biome now correctly filters out files that are not present in the current directory when using the --changed flag #1996. Contributed by @castarco
Biome now skips traversing fifo or socket files (#2311). Contributed by @Sec-ant
Biome now resolves configuration files exported from external libraries in extends from the working directory (CLI) or project root (LSP). This is the documented behavior and previous resolution behavior is considered as a bug (#2231). Contributed by @Sec-ant

Configuration

Bug fixes

Now setting group level all to false can disable recommended rules from that group when top level recommended is true or unset. Contributed by @Sec-ant
Biome configuration files can correctly extends .jsonc configuration files now (#2279). Contributed by @Sec-ant
Fixed the JSON schema for React hooks configuration (#2396). Contributed by @arendjr

Enhancements

Biome now displays the location of a parsing error for its configuration file (#1627).

Previously, when Biome encountered a parsing error in its configuration file, it didn’t indicate the location of the error. It now displays the name of the configuration file and the range where the error occurred.

Contributed by @Conaclos
options is no longer required for rules without any options (#2313).

Previously, the JSON schema required to set options to null when an object is used to set the diagnostic level of a rule without any option. However, if options is set to null, Biome emits an error.

The schema is now fixed and it no longer requires specifying options. This makes the following configuration valid:
```
{
  "linter": {
    "rules": {
      "style": {
        "noDefaultExport": {
          "level": "off"
        }
      }
    }
  }
}
```
Contributed by @Conaclos

Editors

Bug fixes

Biome extension is now able to parse the JSX syntax in files that associated with the javascript language identifier. This is an ad hoc fix, because in the React world, .js files are allowed to include JSX syntax, and these files are often associated with the javascript language identifier in most of the editors. Plus, some editor extensions will also associate .jsx files with the javascript language identifier. Relative links: discussion, #2085. Contributed by @Sec-ant

Formatter

Bug fixes

Fix #2291 by correctly handle comment placement for JSX spread attributes and JSX spread children. Contributed by @ah-yu

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:

New features

Add a new option jsxRuntime to the javascript configuration. When set to reactClassic, the noUnusedImports and useImportType rules use this information to make exceptions for the React global that is required by the React Classic JSX transform.

This is only necessary for React users who haven’t upgraded to the new JSX transform.

Contributed by @Conaclos and @arendjr
Implement #2043: The React rule useExhaustiveDependencies is now also compatible with Preact hooks imported from preact/hooks or preact/compat. Contributed by @arendjr
Add rule noFlatMapIdentity to disallow unnecessary callback use on flatMap. Contributed by @isnakode
Add rule noConstantMathMinMaxClamp, which disallows using Math.min and Math.max to clamp a value where the result itself is constant. Contributed by @mgomulak

Enhancements

style/useFilenamingConvention now allows prefixing a filename with + (#2341).

This is a convention used by Sveltekit and Vike.

Contributed by @Conaclos
style/useNamingConvention now accepts PascalCase for local and top-level variables.

This allows supporting local variables that hold a component or a regular class. The following code is now accepted:
```
function loadComponent() {
  const Component = getComponent();
  return <Component />;
}
```
Contributed by @Conaclos
complexity/useLiteralKeys no longer report computed properties named __proto__ (#2430).

In JavaScript, {["__proto__"]: null} and {__proto__: null} have not the same semantic. The first code set a regular property to null. The second one set the prototype of the object to null. See the MDN Docs for more details.

The rule now ignores computed properties named __proto__.

Contributed by @Conaclos

Bug fixes

Lint rules useNodejsImportProtocol, useNodeAssertStrict, noRestrictedImports, noNodejsModules will no longer check declare module statements anymore. Contributed by @Sec-ant
style/useNamingConvention now accepts any case for variables from object destructuring (#2332).

The following name is now ignored:
```
const { Strange_Style } = obj;
```
Previously, the rule renamed this variable. This led to a runtime error.

Contributed by @Conaclos

Parser

Bug fixes

Fixed an issue when Unicode surrogate pairs were encoded in JavaScript strings using an escape sequence (#2384). Contributed by @arendjr

1.6.4 (2024-04-03)

Analyzer

Bug fixes

An operator with no spaces around in a binary expression no longer breaks the js analyzer (#2243). Contributed by @Sec-ant

CLI

Bug fixes

Fix the printed error count (#2048). Contributed by @Sec-ant

Configuration

Bug fixes

Correctly calculate enabled rules in lint rule groups. Now a specific rule belonging to a group can be enabled even if its group-level preset option recommended or all is false (#2191). Contributed by @Sec-ant

Editors

Bug fixes

Fix the unexpected code deletion and repetition when quickfix.biome is enabled and some import-related rules are applied (#2222, #688, #1015). Contributed by @Sec-ant

Linter

New features

Add nursery/noMisplacedAssertion. COntributed by @ematipico

Bug fixes

Fix #2211. noChildrenProp should work fine when children pass as a prop in a new line. Contributed by @fireairforce
Fix #2248. lint/a11y/useButtonType should not trigger when button element with spread attribute. Contributed by @fireairforce
Fix #2216. lint/style/useNamingConvention should not ignore JSX Component name binding. Contributed by @fireairforce

Enhancements

Add support for object property members in the rule useSortedClasses. Contributed by @ematipico

Parser

The parser doesn’t throw any error when the frontmatter of .astro files contains an illegal return:
```
---
const condition = true;
if (condition) {
  return "Something";
}
---
<div></div>
```
Contributed by @ematipico

1.6.3 (2024-03-25)

CLI

Bug fixes

Fix configuration resolution. Biome is now able to correctly find the biome.jsonc configuration file when --config-path is explicitly set (#2164). Contributed by @Sec-ant
JavaScript/TypeScript files of different variants (.ts, .js, .tsx, .jsx) in a single workspace now have stable formatting behaviors when running the CLI command in paths of different nested levels or in different operating systems (#2080, #2109). Contributed by @Sec-ant

Configuration

Bug fixes

Complete the documentation and overrides support for options formatter.lineEnding, [language].formatter.lineEnding, formatter.attributePosition and javascript.formatter.attributePosition. Contributed by @Sec-ant

Formatter

Bug fixes

Fix #2172 by breaking long object destructuring patterns. Contributed by @ah-yu

Linter

New features

Add rule noEvolvingAny to disallow variables from evolving into any type through reassignments. Contributed by @fujiyamaorange

Enhancements

Rename noSemicolonInJsx to noSuspiciousSemicolonInJsx. Contributed by @fujiyamaorange

LSP

Bug fixes

Quickfix action no longer autofixes lint rule errors on save when linter is disabled (#2161). Contributed by @Sec-ant
Range formatting for Astro/Svelte/Vue doesn’t place code out of place, especially when formatting on paste is enabled. Contributed by @ematipico

1.6.2 (2024-03-22)

Analyzer

Bug fixes

The noSuperWithoutExtends rule now allows for calling super() in derived class constructors of class expressions (#2108). Contributed by @Sec-ant
Fix discrepancies on file source detection. Allow module syntax in .cts files (#2114). Contributed by @Sec-ant

CLI

Bug fixes

Fixes #2131, where folders were incorrectly ignored when running the command check. Now folders are correctly ignored based on their command. Contributed by @ematipico
Smoother handling of "endOfLine": "auto" in prettier migration: falling back to "lf" (#2145). Contributed by @eMerzh

Configuration

Bug fixes

Fix enabled rules calculation. The precendence of individual rules, all and recommend presets in top-level and group-level configs is now correctly respected. More details can be seen in (#2072) (#2028). Contributed by @Sec-ant

Formatter

Bug fixes

Fix #1661. Now nested conditionals are aligned with Prettier’s logic, and won’t contain mixed spaces and tabs. Contributed by @ematipico

JavaScript APIs

Enhancements

Support applying lint fixes when calling the lintContent method of the Biome class (#1956). Contributed by @mnahkies

Linter

New features

Add nursery/noDuplicateElseIf. COntributed by @mdm317

Bug fixes

Rule noUndeclaredDependencies now also validates peerDependencies and optionalDependencies (#2122). Contributed by @Sec-ant
Rule noUndeclaredDependencies won’t check declare module statements anymore (#2123). Contributed by @Sec-ant
Fix #1925. The fix for useOptionalChain would sometimes suggest an incorrect fix that discarded optional chaining operators on the left-hand side of logical expressions. These are now preserved. Contributed by @arendjr
Rule noUndeclaredVariables now also checks for worker globals (#2121). Contributed by @Sec-ant

LSP

Bug fixes

Correctly parse .jsonc files. Contributed by @Sec-ant
Correctly resolve external extends configs. Contributed by @Sec-ant

1.6.1 (2024-03-12)

CLI

Bug fixes

CLI is now able to automatically search and resolve biome.jsonc (#2008). Contributed by @Sec-ant
Fix a false positive where some files were counted as “fixed” even though they weren’t modified. Contributed by @ematipico

Configuration

Bug fixes

json.formatter.trailingCommas option now works in overrides (#2009). Contributed by @Sec-ant

Linter

New features

Add rule noDoneCallback, this rule checks the function parameter of hooks & tests for use of the done argument, suggesting you return a promise instead. Contributed by @vasucp1207
```
beforeEach(done => {
  // ...
});
```

Bug fixes

useJsxKeyInIterable now recognizes function bodies wrapped in parentheses (#2011). Contributed by @Sec-ant
useShorthandFunctionType now preserves type parameters of generic interfaces when applying fixes (#2015). Contributed by @Sec-ant
Code fixes of useImportType and useExportType now handle multiline statements (#2041). Contributed by @Conaclos
noRedeclare no longer reports type parameter and parameter with identical names (#1992).

The following code is no longer reported:
```
function f<a>(a: a) {}
```
Contributed by @Conaclos
noRedeclare now reports duplicate type parameters in a same declaration.

The following type parameters are now reported as a redeclaration:
```
function f<T, T>() {}
```
Contributed by @Conaclos
noUndeclaredDependencies now recognizes imports of subpath exports.

E.g., the following import statements no longer report errors if @mui/material and tailwindcss are installed as dependencies:
```
import Button from "@mui/material/Button";
import { fontFamily } from "tailwindcss/defaultTheme";
```
Contributed by @Sec-ant

Parser

Bug fixes

JavaScript lexer is now able to lex regular expression literals with escaped non-ascii chars (#1941).

Contributed by @Sec-ant

1.6.0 (2024-03-08)

Analyzer

New features

Add partial for .astro files. Biome is able to sort imports inside the frontmatter of the Astro files. Contributed by @ematipico

---
 import { getLocale } from "astro:i18n";
 import { Code } from "astro:components";
 import { Code } from "astro:components";
 import { getLocale } from "astro:i18n";
---

<div></div>

Add partial for .vue files. Biome is able to sort imports inside the script block of Vue files. Contributed by @nhedger

<script setup lang="ts">
 import Button from "./components/Button.vue";
 import * as vueUse from "vue-use";
 import * as vueUse from "vue-use";
 import Button from "./components/Button.vue";
</script/>

<template></template>

Add partial for .svelte files. Biome is able to sort imports inside the script block of Svelte files. Contributed by @ematipico

<script setup lang="ts">
 import Button from "./components/Button.svelte";
 import * as svelteUse from "svelte-use";
 import * as svelteUse from "svelte-use";
 import Button from "./components/Button.svelte";
</script/>

<div></div>

The analyzer now infers the correct quote from javascript.formatter.quoteStyle, if set. This means that code fixes suggested by the analyzer will use the same quote of the formatter. Contributed by @ematipico

Enhancements

noUnusedVariables ignores unused rest spread siblings.

The following code is now valid:
```
const { a, ...rest } = { a: 0, b: 1 };
console.log(rest);
```
Contributed by @ah-yu
Fix #1931. Built-in React hooks such as useEffect() can now be validated by the useExhaustiveDependendies, even when they’re not being imported from the React library. To do so, simply configure them like any other user-provided hooks.

Contributed by @arendjr

Implemented #1128. User-provided React hooks can now be configured to track stable results. For example:

"useExhaustiveDependencies": {
    "level": "error",
    "options": {
        "hooks": [{
            "name": "useMyState",
            "stableResult": [
                1
            ]
        }]
    }
}

This will allow the following to be validated:

const [myState, setMyState] = useMyState();
const toggleMyState = useCallback(() => {
  setMyState(!myState);
}, [myState]); // Only `myState` needs to be specified here.

Contributed by @arendjr

Bug fixes

Fix #1748. Now for the following case we won’t provide an unsafe fix for the noNonNullAssertion rule:
```
x[y.z!];
```
Contributed by @ah-yu

Imports that contain the protocol : are now sorted after the npm: modules, and before the URL modules. Contributed by @ematipico

import express from "npm:express";
 import Component from "./component.js"
 import { sortBy } from "virtual:utils";
 import { sortBy } from "virtual:utils";
 import Component from "./component.js"

Fix #1081. The useAwait rule does not report for await...of. Contributed by @unvalley
Fix #1827 by properly analyzing nested try-finally statements. Contributed by @ah-yu
Fix #1924 Use the correct export name to sort in the import clause. Contributed by @ah-yu
Fix #1805 fix formatting arrow function which has conditional expression body Contributed by @mdm317
Fix #1781 by avoiding the retrieval of the entire static member expression for the reference if the static member expression does not start with the reference. Contributed by @ah-yu

CLI

New features

Add a new command biome migrate prettier. The command will read the file .prettierrc/prettier.json and .prettierignore and map its configuration to Biome’s one. Due to the different nature of .prettierignore globs and Biome’s globs, it’s highly advised to make sure that those still work under Biome.
Now the file name printed in the diagnostics is clickable. If you run the CLI from your editor, you can Ctrl/⌘ + Click on the file name, and the editor will open said file. If row and columns are specified e.g. file.js:32:7, the editor will set the cursor right in that position. Contributed by @ematipico
Add an option --linter to biome rage. The option needs to check Biome linter configuration. Contributed by @seitarof
Add an option --formatter to biome rage. The option needs to check Biome formatter configuration. Contributed by @seitarof
The CLI now consistently reports the number of files tha were changed, out of the total files that were analysed. Contributed by @ematipico
The CLI now consistently shows the number of errors and warnings emitted. Contributed by @ematipico

Bug fixes

Don’t process files under an ignored directory.

Previously, Biome processed all files in the traversed hierarchy, even the files under an ignored directory. Now, it completely skips the content of ignored directories.

For now, directories cannot be ignored using files.include in the configuration file. This is a known limitation that we want to address in a future release.

For instance, if you have a project with a folder src and a folder test, the following configuration doesn’t completely ignore test.
```
{
  "files": {
    "include": ["src"]
  }
}
```
Biome will traverse test, however all files of the directory are correctly ignored. This can result in file system errors, if Biome encounters dangling symbolic links or files with higher permissions.

To avoid traversing the test directory, you should ignore the directory using ignore:
```
{
  "files": {
    "include": ["src"],
    "ignore": ["test"]
  }
}
```
Fix #1508 by excluding deleted files from being processed. Contributed by @ematipico
Fix #1173. Fix the formatting of a single instruction with commented in a control flow body to ensure consistency. Contributed by @mdm317
Fix overriding of javascript.globals. Contributed by @arendjr

Fix a bug where syntax rules weren’t run when pulling the diagnostics. Now Biome will emit more parsing diagnostics, e.g.

check.js:1:17 parse/noDuplicatePrivateClassMembers ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × Duplicate private class member "#foo"

  > 1 │ class A { #foo; #foo }
      │                 ^^^^

Contributed by @ematipico

Fix #1774 by taking into account the option --no-errors-on-unmatched when running the CLI using --changed. Contributed by @antogyn

Enhancements

Removed a superfluous diagnostic that was printed during the linting/check phase of a file:

test.js check ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × The file contains diagnostics that needs to be addressed.

Contributed by @ematipico

The command format now emits parsing diagnostics if there are any, and it will terminate with a non-zero exit code. Contributed by @ematipico

Configuration

New features

Add the ability to resolve the configuration files defined inside extends from the node_modules/ directory.

If you want to resolve a configuration file that matches the specifier @org/configs/biome, then your package.json file must look this:
```
{
  "name": "@org/configs",
  "exports": {
    "./biome": "./biome.json"
  }
}
```
And the biome.json file that “imports” said configuration, will look like this:
```
{
  "extends": "@org/configs/biome"
}
```
Read the documentation to better understand how it works, expectations and restrictions.

Editors

Bug fixes

Fix a regression where ignored files where formatted in the editor. Contributed by @ematipico

Fix a bug where syntax rules weren’t run when pulling the diagnostics. Now Biome will emit more parsing diagnostics, e.g.

check.js:1:17 parse/noDuplicatePrivateClassMembers ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × Duplicate private class member "#foo"

  > 1 │ class A { #foo; #foo }
      │                 ^^^^

Contributed by @ematipico

Formatter

New features

Biome now allows to format the package.json file. This is now the default behaviour and users can remove their workarounds. If you rely on other tools to format package.json, you’ll have to ignore it via configuration. Contributed by @pattrickrice
New formatter option attributePosition that have similar behavior as Prettier singleAttributePerLine #1706. Contributed by @octoshikari
Add partial for .astro files. Biome is able to format the frontmatter of the Astro files. Contributed by @ematipico
```
---
 statement ( );
 statement();
---

<div></div>
```
Add partial for .vue files. Biome is able to format the script block of Vue files. Contributed by @nhedger
```
<script setup lang="ts">
 statement ( );
 statement();
</script/>

<template></template>
```
Add partial for .svelte files. Biome is able to format the script block of Svelte files. Contributed by @ematipico
```
<script setup lang="ts">
 statement ( );
 statement();
</script/>

<div></div>
```

Enhancements

composer.json, deno.json, jsconfig.json, package.json and tsconfig.json are no longer protected files.

This means that you can now format them.

If you want to ignore these files, you can use the files.ignore configuration:
```
{
  "files": {
    "ignore": [
      "composer.json",
      "jsconfig.json",
      "package.json",
      "tsconfig.json",
      "typescript.json",
      "deno.json",
      "deno.jsonc"
    ]
  }
}
```
The following files are still protected, and thus ignored:
- composer.lock
- npm-shrinkwrap.json
- package-lock.json
- yarn.lock
Contributed by @pattrickrice and @Conaclos

Bug fixes

Fix #1039. Check unicode width instead of number of bytes when checking if regex expression is a simple argument.

This no longer breaks.
```
s(/🚀🚀/).s().s();
```
Contributed by @kalleep
Fix #1218, by correctly preserving empty lines in member chains. Contributed by @ah-yu
Fix #1659 and #1662, by correctly taking into account the leading comma inside the formatter options. Contributed by @ematipico
Fix #1934. Fix invalid formatting of long arrow function for AsNeeded arrow parens Contributed by @fireairforce

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:

Additionally, the following rules are now recommended:

Removed rules

Remove nursery/useGroupedTypeImport. The rule style/useImportType covers the behavior of this rule.

Note that removing a nursery rule is not considered a breaking change according to our semantic versioning.

Contributed by @Conaclos

New features

Add the rule noSkippedTests, to disallow skipped tests:
```
describe.skip("test", () => {});
it.skip("test", () => {});
```
Contributed by @ematipico
Add the rule noFocusedTests, to disallow skipped tests:
```
describe.only("test", () => {});
it.only("test", () => {});
```
Contributed by @ematipico
Add rule useSortedClasses, to sort CSS utility classes:
```
<div class="px-2 foo p-4 bar" />
<div class="foo bar p-4 px-2" />
```
Contributed by @DaniGuardiola
Add rule noUndeclaredDependencies, to detect the use of dependencies that aren’t present in the package.json.

The rule ignores imports using a protocol such as node:, bun:, jsr:, https:.

Contributed by @ematipico and @Conaclos
Add rule noNamespaceImport, to report namespace imports:
```
import * as foo from "foo";
```
Contributed by @unvalley
Add partial support for .astro files. Biome is able to lint and fix the frontmatter of the Astro files. Contributed by @ematipico
```
---
 delete a.b
 a.b = undefined
---

<div></div>
```
Add partial support for .vue files. Biome is able to lint and fix the script block of the Vue files.
```
<script setup lang="ts">
 delete a.b
 a.b = undefined
<script>

<template></template>
```
Contributed by @nhedger
Add rule useNodeAssertStrict, which promotes the use of node:assert/strict over node:assert. Contributed by @ematipico
Add rule noExportsInTest which disallows export or modules.exports in files containing test. Contributed by @ah-yu
Add rule noSemicolonInJsx to detect possible wrong semicolons inside JSX elements.
```
const Component = () => {
  return (
    <div>
      <div />;
    </div>
  );
}
```
Contributed by @fujiyamaorange
Add rule noBarrelFile, to report the usage of barrel file:
```
export * from "foo";
```
Contributed by @togami2864
Add rule noReExportAll that report export * from "mod". Contributed by @mdm317
Add rule noExcessiveNestedTestSuites. Contributed by @vasucp1207
Add rule useJsxKeyInIterable. Contributed by @vohoanglong0107

Enhancements

noUselessFragments now rule not triggered for jsx attributes when the fragment child is simple text.
```
export function SomeComponent() {
  return <div x-some-prop={<>Foo</>} />;
}
```
Also fixes code action when the fragment child is of type JsxExpressionChild.
```
<>
  <Hello leftIcon={<>{provider?.icon}</>} />
  {<>{provider?.icon}</>}
  <>{provider?.icon}</>
</>
```
Contributed by @vasucp1207
noUselessTernary now provides unsafe code fixes. Contributed by @vasucp1207
noApproximativeNumericConstant now provides unsafe code fixes and handle numbers without leading zero and numbers with digit separators.

The following numbers are now reported as approximated constants.
```
3.14_15; // PI
.4342; // LOG10E
```
Contributed by @Conaclos
noPrecisionLoss no longer reports number with extra zeros.

The following numbers are now valid.
```
.1230000000000000000000000;
1230000000000000000000000.0;
```
Contributed by @Conaclos
useNamingConvention now supports unicase letters (#1786).

unicase letters have a single case: they are neither uppercase nor lowercase. Previously, Biome reported names in unicase as invalid. It now accepts a name in unicase everywhere.

The following code is now accepted:
```
const 안녕하세요 = { 안녕하세요: 0 };
```
We still reject a name that mixes unicase characters with lowercase or uppercase characters: The following names are rejected:
```
const A안녕하세요 = { a안녕하세요: 0 };
```
Contributed by @Conaclos
useNamingConvention and useFilenamingConvention now provides a new option requireAscii to require identifiers to be in ASCII.

To avoid any breaking change, this option is turned off by default. We intend to turn it on in the next major release of Biome (Biome 2.0).

Set the requireAscii rule option to true to require identifiers to be in ASCII.
```
{
  "linter": {
    "rules": {
      "style": {
        "useNamingConvention": { "options": { "requireAscii": false } }
      },
      "nursery": {
        "useFilenamingConvention": { "options": { "requireAscii": false } }
      }
    }
  }
}
```
Contributed by @Conaclos
noUnusedVariables no longer reports unused imports.

We now have a dedicated rule for reporting unused imports: noUnusedImports

Contributed by @Conaclos

Bug fixes

Fix missing link in noStaticOnlyClass documentation. Contributed by @yndajas
noConfusingVoidType no longer reports valid use of the void type in conditional types (#1812).

The rule no longer reports the following code:
```
type Conditional<T> = T extends void ? Record<string, never> : T
```
Contributed by @lucasweng
noInvalidUseBeforeDeclaration no longer reports valid use of binding patterns (#1648).

The rule no longer reports the following code:
```
const { a = 0, b = a } = {};
```
Contributed by @Conaclos
noUnusedVariables no longer reports used binding patterns (#1652).

The rule no longer reports a as unused the following code:
```
const { a = 0, b = a } = {};
export { b };
```
Contributed by @Conaclos
Fix #1651. noVar now ignores TsGlobalDeclaration. Contributed by @vasucp1207
Fix #1640. useEnumInitializers code action now generates valid code when last member has a comment but no comma. Contributed by @kalleep
Fix #1653. Handle a shorthand value in useForOf to avoid the false-positive case. Contributed by @togami2864
Fix #1656. useOptionalChain code action now correctly handles logical and chains where methods with the same name are invoked with different arguments:
```
tags && tags.includes('a') && tags.includes('b')
tags?.includes('a') && tags.includes('b')
```
Contributed by @lucasweng
Fix #1704. Convert / to escaped slash \/ to avoid parsing error in the result of autofix. Contributed by @togami2864
Fix#1697. Preserve leading trivia in autofix of suppression rules. Contributed by @togami2864
Fix #603. Trim trailing whitespace to avoid double insertion. Contributed by @togami2864
Fix #1765. Now the rule noDelete doesn’t trigger when deleting a dataset:
```
delete element.dataset.prop;
```
Contributed by @ematipico
useNamingConvention and useFilenamingConvention now reject identifiers with consecutive delimiters.

The following name is now invalid because it includes two underscores:
```
export const MY__CONSTANT = 0;
```
Note that we still allow consecutive leading and consecutive trailing underscores.

Contributed by @Conaclos
Fix #1932 Allow redeclaration of type parameters in different declarations. Contributed by @keita-hino
Fix #1945 Allow constructor with default parameters in noUselessConstructor
Fix #1982 Change to iterate over the module item lists and ignore .d.ts files. Contributed by @togami2864

Parser

Bug fixes

Fix #1728. Correctly parse the global declaration when the { token is on the line following the global keyword.

Now the following code is correctly parsed:
```
declare global
{ }

declare module foo {
  global
  { }
}
```
Contributed by @ah-yu
Fix #1730. Correctly parse delete expressions with operands that are not simple member expressions.
```
delete(a.b);
delete console.log(1);
delete(() => {});
```
Contributed by @printfn

Website

Bug fixes

Fix #1981. Identify TypeScript definition files by their file path within the playground. Contributed by @ah-yu

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/.
Terminal window
```
❯ 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
Terminal window
```
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
Terminal window
```
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
Terminal window
```
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:
Terminal window
```
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:

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:
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

1.4.1 (2023-11-30)

Editors

Bug fixes

Fix #933. Some files are properly ignored in the LSP too. E.g. package.json, tsconfig.json, etc.
Fix #1394, by inferring the language extension from the internal saved files. Now newly created files JavaScript correctly show diagnostics.

Formatter

Bug fixes

Fix some accidental line breaks when printing array expressions within arrow functions and other long lines #917. Contributed by @faultyserver
Match Prettier’s breaking strategy for ArrowChain layouts #934. Contributed by @faultyserver
Fix double-printing of leading comments in arrow chain expressions #951. Contributed by @faultyserver

Linter

Bug fixes

Fix #910, where the rule noSvgWithoutTitle should skip elements that have aria-hidden attributes. Contributed by @vasucp1207

New features

Add useForOf rule. The rule recommends a for-of loop when the loop index is only used to read from an array that is being iterated. Contributed by @victor-teles

Enhancement

Address #924 and #920. noUselessElse now ignores else clauses that follow at least one if statement that doesn’t break early. Contributed by @Conaclos

For example, the following code is no longer reported by the rule:

function f(x) {
    if (x < 0) {
      // this `if` doesn't break early.
    } else if (x > 0) {
        return x;
    } else {
        // This `else` block was previously reported as useless.
    }
}

Bug fixes

Fix #918. useSimpleNumberKeys no longer repports false positive on comments. Contributed by @kalleep

Fix #953. noRedeclare no longer reports type parameters with the same name in different mapped types as redeclarations. Contributed by @Conaclos

Fix #608. useExhaustiveDependencies no longer repports missing dependencies for React hooks without dependency array. Contributed by @kalleep

Parser

1.4.0 (2023-11-27)

CLI

Remove the CLI options from the lsp-proxy, as they were never meant to be passed to that command. Contributed by @ematipico
Add option --config-path to lsp-proxy and start commands. It’s now possible to tell the Daemon server to load biome.json from a custom path. Contributed by @ematipico
Add option --diagnostic-level. It lets users control the level of diagnostics printed by the CLI. Possible values are: "info", "warn", and "hint". Contributed by @simonxabris
Add option --line-feed to the format command. Contributed by @SuperchupuDev
Add option --bracket-same-line to the format command. Contributed by @faultyserver
Add option --bracket-spacing to the format command. Contributed by @faultyserver

Bug fixes

Fix the command format, now it returns a non-zero exit code when if there pending diffs. Contributed by @ematipico

Formatter

New features

Add the configuration formatter.lineFeed. It allows changing the type of line endings. Contributed by @SuperchupuDev
Add the configuration javascript.formatter.bracketSameLine. It allows controlling whether ending > of a multi-line JSX element should be on the last attribute line or not. #627. Contributed by @faultyserver
Add the configuration javascript.formatter.bracketSpacing. It allows controlling whether spaces are inserted around the brackets of object literals. #627. Contributed by @faultyserver

Bug fixes

Fix #832, the formatter no longer keeps an unnecessary trailing comma in type parameter lists. Contributed by @Conaclos
```
class A<T,> {}
class A<T> {}
```
Fix #301, the formatter should not break before the in keyword. Contributed by @ematipico

Linter

Promoted rules

The following rules are now recommended:

The following rules are now deprecated:

correctness/noNewSymbol The rule is replaced by correctness/noInvalidNewBuiltin

New features

Add noDefaultExport which disallows export default. Contributed by @Conaclos
Add noAriaHiddenOnFocusable which reports hidden and focusable elements. Contributed by @vasucp1207
Add noImplicitAnyLet that reports variables declared with let and without initialization and type annotation. Contributed by @TaKO8Ki and @b4s36t4
Add useAwait that reports async functions that don’t use an await expression.
Add useValidAriaRole. Contributed by @vasucp1207
Add useRegexLiterals that suggests turning call to the regex constructor into regex literals. COntributed by @Yuiki

Enhancements

Add an unsafe code fix for a11y/useAriaActivedescendantWithTabindex

Bug fixes

Fix #639 by ignoring unused TypeScript’s mapped key. Contributed by @Conaclos
Fix #565 by handling several infer with the same name in extends clauses of TypeScript’s conditional types. Contributed by @Conaclos

Fix #653. noUnusedImports now correctly removes the entire line where the unused import is. Contributed by @Conaclos

Fix #607 useExhaustiveDependencies, ignore optional chaining, Contributed by @msdlisper
Fix #676, by using the correct node for the "noreferrer" when applying the code action. Contributed by @ematipico
Fix #455. The CLI can now print complex emojis to the console correctly.

Fix #727. noInferrableTypes now correctly keeps type annotations when the initialization expression is null. Contributed by @Conaclos

Fix #784, noSvgWithoutTitle fixes false-positives to aria-label and reports svg’s role attribute is implicit. Contributed by @unvalley

Fix #834 that made noUselessLoneBlockStatements reports block statements of switch clauses. Contributed by @vasucp1207
Fix #783 that made noUselessLoneBlockStatements reports block statements of try-catch structures. Contributed by @hougesen
Fix #69 that made correctness/noUnnecessaryContinue incorrectly reports a continue used to break a switch clause. Contributed by @TaKO8Ki
Fix #664 by improving the diagnostic of style/useNamingConvention when double capital are detected in strict camel case mode. Contributed by @vasucp1207
Fix #643 that erroneously parsed the option of complexity/useExhaustiveDependencies. Contributed by @arendjr

Parser

Bug fixes

Fix #846 that erroneously parsed <const T,>() => {} as a JSX tag instead of an arrow function when both TypeScript and JSX are enabled.

VSCode

1.3.3 (2023-10-31)

Analyzer

Bug fixes

Fix #604 which made noConfusingVoidType report false positives when the void type is used in a generic type parameter. Contributed by @unvalley

CLI

Bug fixes

Fix how overrides behave. Now ignore and include apply or not the override pattern, so they override each other. Now the options inside overrides override the top-level options.
Bootstrap the logger only when needed. Contributed by @ematipico
Fix how overrides are run. The properties ignore and include have different semantics and only apply/not apply an override. Contributed by @ematipico

Editors

Bug fixes

Fix #592, by changing binary resolution in the IntelliJ plugin. Contributed by @Joshuabaker2

Formatter

Bug fixes

Apply the correct layout when the right hand of an assignment expression is an await expression or a yield expression. Contributed by @ematipico
Fix #303, where nested arrow functions didn’t break. Contributed by @victor-teles

Linter

New features

Add noUnusedPrivateClassMembers rule. The rule disallow unused private class members. Contributed by @victor-teles

Bug fixes

Fix #175 which made noRedeclare report index signatures using the name of a variable in the parent scope.
Fix #557 which made noUnusedImports report imported types used in typeof expression. Contributed by @Conaclos
Fix #576 by removing some erroneous logic in noSelfAssign. Contributed by @ematipico
Fix #861 that made noUnusedVariables always reports the parameter of a non-parenthesize arrow function as unused.
Fix #595 by updating unsafe-apply logic to avoid unexpected errors in noUselessFragments. Contributed by @nissy-dev
Fix #591 which made noRedeclare report type parameters with identical names but in different method signatures. Contributed by @Conaclos
Support more a11y roles and fix some methods for a11y lint rules Contributed @nissy-dev
Fix #609 useExhaustiveDependencies, by removing useContext, useId and useSyncExternalStore from the known hooks. Contributed by @msdlisper
Fix useExhaustiveDependencies, by removing useContext, useId and useSyncExternalStore from the known hooks. Contributed by @msdlisper
Fix #871 and #610. Now useHookAtTopLevel correctly handles nested functions. Contributed by @arendjr

The options of the rule useHookAtTopLevel are deprecated and will be removed in Biome 2.0. The rule now determines the hooks using the naming convention set by React.

{
  "linter": {
    "rules": {
      "correctness": {
        "useHookAtTopLevel": "error",
        "useHookAtTopLevel": {
          "level": "error",
          "options": {
            "hooks": [
              {
                "name": "useLocation",
                "closureIndex": 0,
                "dependenciesIndex": 1
              },
              { "name": "useQuery", "closureIndex": 1, "dependenciesIndex": 0 }
            ]
          }
        }
      }
    }
  }
}

Parser

Enhancements

Support RegExp v flag. Contributed by @nissy-dev
Improve error messages. Contributed by @ematipico

1.3.1 (2023-10-20)

CLI

Bug fixes

Fix rage command, now it doesn’t print info about running servers. Contributed by @ematipico

Editors

Bug fixes

Fix #552, where the formatter isn’t correctly triggered in Windows systems. Contributed by @victor-teles

Linter

New features

Add noThisInStatic rule. Contributed by @ditorodev and @Conaclos

Bug fixes

Fix #548 which made noSelfAssign panic.
Fix #555, by correctly map globals into the workspace.

1.3.0 (2023-10-19)

Analyzer

Enhancements

Import sorting is safe to apply now, and it will be applied when running check --apply instead of check --apply-unsafe.
Import sorting now handles Bun imports bun:<name>, absolute path imports /<path>, and Node’s subpath imports #<name>. See our documentation for more details. Contributed by @Conaclos

CLI

Bug fixes

Fix #319. The command biome lint now shows the correct options. Contributed by @ematipico
Fix #312. Running biome --version now exits with status code 0 instead of 1. Contributed by @nhedger
Fix a bug where the extends functionality doesn’t carry over organizeImports.ignore. Contributed by @ematipico
The CLI now returns the original content when using stdin and the original content doesn’t change. Contributed by @ematipico

New features

Add support for BIOME_BINARY environment variable to override the location of the binary. Contributed by @ematipico
Add option --indent-width, and deprecated the option --indent-size. Contributed by @ematipico
Add option --javascript-formatter-indent-width, and deprecated the option --javascript-formatter-indent-size. Contributed by @ematipico
Add option --json-formatter-indent-width, and deprecated the option --json-formatter-indent-size. Contributed by @ematipico
Add option --daemon-logs to biome rage. The option is required to view Biome daemon server logs. Contributed by @unvalley

Add support for logging. By default, Biome doesn’t log anything other than diagnostics. Logging can be enabled with the new option --log-level:

biome format --log-level=info ./src

There are four different levels of logging, from the most verbose to the least verbose: debug, info, warn and error. Here’s how an INFO log will look like:

2023-10-05T08:27:01.954727Z  INFO  Analyze file ./website/src/playground/components/Resizable.tsx
  at crates/biome_service/src/file_handlers/javascript.rs:298 on biome::worker_5
  in Pulling diagnostics with categories: RuleCategories(SYNTAX)
  in Processes formatting with path: "./website/src/playground/components/Resizable.tsx"
  in Process check with path: "./website/src/playground/components/Resizable.tsx"

You can customize how the log will look like with a new option --log-kind. The supported kinds are: pretty, compact and json.

pretty is the default logging. Here’s how a compact log will look like:

2023-10-05T08:29:04.864247Z  INFO biome::worker_2 Process check:Processes linting:Pulling diagnostics: crates/biome_service/src/file_handlers/javascript.rs: Analyze file ./website/src/playground/components/Resizable.tsx path="./website/src/playground/components/Resizable.tsx" path="./website/src/playground/components/Resizable.tsx" categories=RuleCategories(LINT)
2023-10-05T08:29:04.864290Z  INFO biome::worker_7 Process check:Processes formatting: crates/biome_service/src/file_handlers/javascript.rs: Format file ./website/src/playground/components/Tabs.tsx path="./website/src/playground/components/Tabs.tsx" path="./website/src/playground/components/Tabs.tsx"
2023-10-05T08:29:04.879332Z  INFO biome::worker_2 Process check:Processes formatting:Pulling diagnostics: crates/biome_service/src/file_handlers/javascript.rs: Analyze file ./website/src/playground/components/Resizable.tsx path="./website/src/playground/components/Resizable.tsx" path="./website/src/playground/components/Resizable.tsx" categories=RuleCategories(SYNTAX)
2023-10-05T08:29:04.879383Z  INFO biome::worker_2 Process check:Processes formatting: crates/biome_service/src/file_handlers/javascript.rs: Format file ./website/src/playground/components/Resizable.tsx path="./website/src/playground/components/Resizable.tsx" path="./website/src/playground/components/Resizable.tsx"

Enhancements

Deprecated the environment variable ROME_BINARY. Use BIOME_BINARY instead. Contributed by @ematipico
Biome doesn’t check anymore the presence of the .git folder when VCS support is enabled. Contributed by @ematipico
biome rage doesn’t print the logs of the daemon, use biome rage --daemon-logs to print them. Contributed by @unvalley

Configuration

New features

Add option formatter.indentWidth, and deprecated the option formatter.indentSize. Contributed by @ematipico
Add option javascript.formatter.indentWidth, and deprecated the option javascript.formatter.indentSize. Contributed by @ematipico
Add option json.formatter.indentWidth, and deprecated the option json.formatter.indentSize. Contributed by @ematipico
Add option include to multiple sections of the configuration
- files.include;
- formatter.include;
- linter.include;
- organizeImports.include; When include and ignore are both specified, ignore takes precedence over include

Add option overrides, where users can modify the behaviour of the tools for certain files or paths.

For example, it’s possible to modify the formatter lineWidth, and even quoteStyle for certain files that are included in glob path generated/**:

{
  "formatter": {
    "lineWidth": 100
  },
  "overrides": [
    {
      "include": ["generated/**"],
      "formatter": {
        "lineWidth": 160
      },
      "javascript": {
        "formatter": {
          "quoteStyle": "single"
        }
      }
    }
  ]
}

Or, you can disable certain rules for certain path, and disable the linter for other paths:

{
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true
    }
  },
  "overrides": [
    {
      "include": ["lib/**"],
      "linter": {
        "rules": {
          "suspicious": {
            "noDebugger": "off"
          }
        }
      }
    },
    {
      "include": ["shims/**"],
      "linter": {
        "enabled": false
      }
    }
  ]
}

Bug fixes

Fix #343, extends was incorrectly applied to the biome.json file. Contributed by @ematipico

Editors

Bug fixes

Fix #404. Biome intellij plugin now works on Windows. Contributed by @victor-teles
Fix #402. Biome format on intellij plugin now recognize biome.json. Contributed by @victor-teles

Formatter

Enhancements

Use OnceCell for the Memoized memory because that’s what the RefCell<Option> implemented. Contributed by @denbezrukov

Linter

Promoted rules

The following rules are now recommended:

New features

Add noEmptyCharacterClassInRegex rule. The rule reports empty character classes and empty negated character classes in regular expression literals. Contributed by @Conaclos
Add noMisleadingInstantiator rule. The rule reports the misleading use of the new and constructor methods. Contributed by @unvalley
Add noUselessElse rule. The rule reports else clauses that can be omitted because their if branches break. Contributed by @Conaclos
Add noUnusedImports rule. The rule reports unused imports and suggests removing them. Contributed by @Conaclos

noUnusedVariables reports also unused imports, but don’t suggest their removal. Once noUnusedImports stabilized, noUnusedVariables will not report unused imports.
Add useShorthandAssign rule. The rule enforce use of shorthand operators that combine variable assignment and some simple mathematical operations. For example, x = x + 4 can be shortened to x += 4. Contributed by @victor-teles
Add useAsConstAssertion rule. The rule enforce use of as const assertion to infer literal types. Contributed by @unvalley
Add noMisrefactoredShorthandAssign rule. The rule reports shorthand assigns when variable appears on both sides. For example x += x + b Contributed by @victor-teles
Add noApproximativeNumericConstant rule. Contributed by @nikeee

Add noInteractiveElementToNoninteractiveRole rule. The rule enforces the non-interactive ARIA roles are not assigned to interactive HTML elements. Contributed by @nissy-dev

Add useAriaActivedescendantWithTabindex rule. The rule enforces that tabIndex is assigned to non-interactive HTML elements with aria-activedescendant. Contributed by @nissy-dev
Add noUselessLoneBlockStatements rule. The rule reports standalone blocks that don’t include any lexical scoped declaration. Contributed by @emab
Add noInvalidNewBuiltin rule. The rule reports use of new on Symbol and BigInt. Contributed by @lucasweng

Enhancements

The following rules have now safe code fixes:
noAccumulatingSpread makes more check in order to reduce potential false positives. Contributed by @Vivalldi
noConstAssign now provides an unsafe code fix that replaces const with let. Contributed by @vasucp1207
noExcessiveComplexity default complexity threshold is now 15. Contributed by @arendjr
noPositiveTabindexValue now provides an unsafe code fix that set to 0 the tab index. Contributed by @vasucp1207
noUnusedLabels no longer reports unbreakable labeled statements. Contributed by @Conaclos
noUnusedVariables now reports unused TypeScript’s type parameters. Contributed by @Conaclos
useAnchorContent now provides an unsafe code fix that removes the `aria-hidden“ attribute. Contributed by @vasucp1207
useValidAriaProps now provides an unsafe code fix that removes invalid properties. Contributed by @vasucp1207
noExcessiveComplexity was renamed to noExcessiveCognitiveComplexity

Bug fixes

Fix #294. noConfusingVoidType no longer reports false positives for return types. Contributed by @b4s36t4

Fix #313. noRedundantUseStrict now keeps leading comments.

Fix #383. noMultipleSpacesInRegularExpressionLiterals now provides correct code fixes when consecutive spaces are followed by a quantifier. Contributed by @Conaclos

Fix #397. useNumericLiterals now provides correct code fixes for signed numbers. Contributed by @Conaclos

Fix 452. The linter panicked when it met a malformed regex (a regex not ending with a slash).
Fix #104. We now correctly handle types and values with the same name.
Fix #243 a false positive case where the incorrect scope was defined for the infer type in rule noUndeclaredVariables. Contributed by @denbezrukov
Fix #322, now noSelfAssign correctly handles literals inside call expressions.
Changed how noSelfAssign behaves. The rule is not triggered anymore on function calls. Contributed by @ematipico

Parser

Enhance diagnostic for infer type handling in the parser. The ‘infer’ keyword can only be utilized within the ’ extends’ clause of a conditional type. Using it outside this context will result in an error. Ensure that any type declarations using ‘infer’ are correctly placed within the conditional type structure to avoid parsing issues. Contributed by @denbezrukov

Add support for parsing trailing commas inside JSON files:

{
  "json": {
    "parser": {
      "allowTrailingCommas": true
    }
  }
}

Contributed by @nissy-dev

VSCode

1.2.2 (2023-09-16)

CLI

Bug fixes

Fix a condition where import sorting wasn’t applied when running biome check --apply

1.2.1 (2023-09-15)

Configuration

Fix an edge case where the formatter language configuration wasn’t picked.
Fix the configuration schema, where json.formatter properties weren’t transformed in camel case.

1.2.0 (2023-09-15)

CLI

New features

Add new options to customize the behaviour the formatter based on the language of the file
- --json-formatter-enabled
- --json-formatter-indent-style
- --json-formatter-indent-size
- --json-formatter-line-width
- --javascript-formatter-enabled
- --javascript-formatter-indent-style
- --javascript-formatter-indent-size
- --javascript-formatter-line-width

Bug fixes

Fix a bug where --errors-on-warning didn’t work when running biome ci command.

Configuration

New features

Add new options to customize the behaviour of the formatter based on the language of the file
- json.formatter.enabled
- json.formatter.indentStyle
- json.formatter.indentSize
- json.formatter.lineWidth
- javascript.formatter.enabled
- javascript.formatter.indentStyle
- javascript.formatter.indentSize
- javascript.formatter.lineWidth

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:

New rules

Add noConfusingVoidType rule. The rule reports the unusual use of the void type. Contributed by @shulandmimi

Removed rules

Remove noConfusingArrow

Code formatters, such as prettier and Biome, always adds parentheses around the parameter or the body of an arrow function. This makes the rule useless.

Contributed by @Conaclos

Enhancements

noFallthroughSwitchClause now relies on control flow analysis to report most of the switch clause fallthrough. Contributed by @Conaclos
noAssignInExpressions no longer suggest code fixes. Most of the time the suggestion didn’t match users’ expectations. Contributed by @Conaclos
noUselessConstructor no longer emits safe code fixes. Contributed by @Conaclos

All code fixes are now emitted as unsafe code fixes. Removing a constructor can change the behavior of a program.
useCollapsedElseIf now only provides safe code fixes. Contributed by @Conaclos
noUnusedVariables now reports more cases.

The rule is now able to ignore self-writes. For example, the rule reports the following unused variable:
```
let a = 0;
a++;
a += 1;
```
The rule is also capable of detecting an unused declaration that uses itself. For example, the rule reports the following unused interface:
```
interface I {
  instance(): I
}
```
Finally, the rule now ignores all TypeScript declaration files, including global declaration files.

Contributed by @Conaclos

Bug fixes

Fix #182, making useLiteralKeys retains optional chaining. Contributed by @denbezrukov
Fix #168, fix useExhaustiveDependencies false positive case when stable hook is on a new line. Contributed by @denbezrukov

Fix #137, fix noRedeclare false positive case with TypeScript module declaration:

declare module '*.gif' {
    const src: string;
}

declare module '*.bmp' {
    const src: string;
}

Contributed by @denbezrukov

Fix #258, fix noUselessFragments the case where the rule removing an assignment. Contributed by @denbezrukov
Fix #266, where complexity/useLiteralKeys emitted a code action with an invalid AST. Contributed by @ematipico
Fix #105, removing false positives reported by noUnusedVariables.

The rule no longer reports the following used variable:
```
const a = f(() => a);
```
Contributed by @Conaclos

VSCode

Enhancements

Improve server binary resolution when using certain package managers, notably pnpm.

The new strategy is to point to node_modules/.bin/biome path, which is consistent for all package managers.

1.1.2 (2023-09-07)

Editors

Bug fixes

Fix a case where an empty JSON file would cause the LSP server to crash. Contributed by @ematipico

Linter

Enhancements

useNamingConvention now accepts import namespaces in PascalCase and rejects export namespaces in CONSTANT_CASE.

The following code is now valid:
```
import * as React from "react";
```
And the following code is now invalid:
```
export * as MY_NAMESPACE from "./lib.js";
```
Contributed by @Conaclos
noUselessConstructor now ignores decorated classes and decorated parameters. The rule now gives suggestions instead of safe fixes when parameters are annotated with types. Contributed by @Conaclos

1.1.1 (2023-09-07)

Analyzer

Bug fixes

The diagnostic for // rome-ignore suppression comment should not be a warning. A warning could block the CI, marking a gradual migration difficult. The code action that changes // rome-ignore to // biome-ignore is disabled as consequence. Contributed by @ematipico

1.1.0 (2023-09-06)

Analyzer

Enhancements

Add a code action to replace rome-ignore with biome-ignore. Use biome check --apply-unsafe to update all the comments. The action is not bulletproof, and it might generate unwanted code, that’s why it’s unsafe action. Contributed by @ematipico

CLI

Enhancements

Biome now reports a diagnostics when a rome.json file is found.
biome migrate --write creates biome.json from rome.json, but it won’t delete the rome.json file. Contributed by @ematipico

Bug fixes

Biome uses biome.json first, then it attempts to use rome.json.
Fix a case where Biome couldn’t compute correctly the ignored files when the VSC integration is enabled. Contributed by @ematipico

Configuration

Editors

Bug fixes

The LSP now uses its own socket and won’t rely on Biome’s socket. This fixes some cases where users were seeing multiple servers in the rage output.

Formatter

Enhancements

You can use // biome-ignore as suppression comment.
The // rome-ignore suppression is deprecated.

JavaScript APIs

Linter

New features

Add useCollapsedElseIf rule. This new rule requires merging an else and an if, if the if statement is the only statement in the else block. Contributed by @n-gude

Enhancements

useTemplate now reports all string concatenations.

Previously, the rule ignored concatenation of a value and a newline or a backquote. For example, the following concatenation was not reported:
```
v + "\n";
"`" + v + "`";
```
The rule now reports these cases and suggests the following code fixes:
```
v + "\n";
`${v}\n`;
v + "`";
`\`${v}\``;
```
Contributed by @Conaclos
useExponentiationOperator suggests better code fixes.

The rule now preserves any comment preceding the exponent, and it preserves any parenthesis around the base or the exponent. It also adds spaces around the exponentiation operator **, and always adds parentheses for pre- and post-updates.
```
Math.pow(a++, /**/ (2))
(a++) ** /**/ (2)
```
Contributed by @Conaclos
You can use // biome-ignore as suppression comment.
The // rome-ignore suppression is deprecated.

Bug fixes

Fix #80, making noDuplicateJsxProps case-insensitive.

Some frameworks, such as Material UI, rely on the case-sensitivity of JSX properties. For example, TextField has two properties with the same name, but distinct cases:
```
<TextField inputLabelProps="" InputLabelProps=""></TextField>
```
Contributed by @Conaclos
Fix #138

noCommaOperator now correctly ignores all use of comma operators inside the update part of a for loop. The following code is now correctly ignored:
```
for (
  let i = 0, j = 1, k = 2;
  i < 100;
  i++, j++, k++
) {}
```
Contributed by @Conaclos
Fix rome#4713.

Previously, useTemplate made the following suggestion:
```
a + b + "px"
`${a}${b}px`
```
This breaks code where a and b are numbers.

Now, the rule makes the following suggestion:
```
a + b + "px"
`${a + b}px`
```
Contributed by @Conaclos
Fix rome#4109

Previously, useTemplate suggested an invalid code fix when a leading or trailing single-line comment was present:
```
// leading comment
1 /* inner comment */ + "+" + 2 // trailing comment
`${// leading comment
1 /* inner comment */}+${2 //trailing comment}` // trailing comment
```
Now, the rule correctly handles this case:
```
// leading comment
1 + "+" + 2 // trailing comment
`${1}+${2}` // trailing comment
```
As a sideeffect, the rule also suggests the removal of any inner comments.

Contributed by @Conaclos
Fix rome#3850

Previously useExponentiationOperator suggested invalid code in a specific edge case:
```
1 +Math.pow(++a, 2)
1 +++a**2
```
Now, the rule properly adds parentheses:
```
1 +Math.pow(++a, 2)
1 +(++a) ** 2
```
Contributed by @Conaclos
Fix #106

noUndeclaredVariables now correctly recognizes some TypeScript types such as Uppercase.

Contributed by @Conaclos
Fix rome#4616

Previously noUnreachableSuper reported valid codes with complex nesting of control flow structures.

Contributed by @Conaclos

1.0.0 (2023-08-28)

Analyzer

BREAKING CHANGES

The organize imports feature now groups import statements by “distance”.

Modules “farther” from the user are put on the top, and modules “closer” to the user are placed on the bottom. Check the documentation for more information about it.
The organize imports tool is enabled by default. If you don’t want to use it, you need to disable it explicitly:
```
{
  "organizeImports": {
    "enabled": false
  }
}
```

CLI

BREAKING CHANGES

The CLI now exists with an error when there’s an error inside the configuration.

Previously, biome would raise warnings and continue the execution by applying its defaults.

This could have been better for users because this could have created false positives in linting or formatted code with a configuration that wasn’t the user’s.
The command biome check now shows formatter diagnostics when checking the code.

The diagnostics presence will result in an error code when the command finishes.

This aligns with semantic and behaviour meant for the command biome check.
init command emits a biome.json file;

Other changes

Fix #4670, don’t crash at empty default export.
Fix #4556, which correctly handles new lines in the .gitignore file across OS.
Add a new option to ignore unknown files --files-ignore-unknown:
Terminal window
```
biome format --files-ignore-unknown ./src
```
Doing so, Biome won’t emit diagnostics for files that doesn’t know how to handle.
Add the new option --no-errors-on-unmatched:
Terminal window
```
biome format --no-errors-on-unmatched ./src
```
Biome doesn’t exit with an error code if no files were processed in the given paths.
Fix the diagnostics emitted when running the biome format command.
Biome no longer warns when discovering (possibly infinite) symbolic links between directories.

This fixes #4193 which resulted in incorrect warnings when a single file or directory was pointed at by multiple symbolic links. Symbolic links to other symbolic links do still trigger warnings if they are too deeply nested.
Introduced a new command called biome lint, which will only run lint rules against the code base.
Biome recognizes known files as “JSON files with comments allowed”:
- typescript.json;
- tsconfig.json;
- jsconfig.json;
- tslint.json;
- babel.config.json;
- .babelrc.json;
- .ember-cli;
- typedoc.json;
- .eslintrc.json;
- .eslintrc;
- .jsfmtrc;
- .jshintrc;
- .swcrc;
- .hintrc;
- .babelrc;
Add support for biome.json;

Configuration

Other changes

Add a new option to ignore unknown files:
```
{
   "files": {
      "ignoreUnknown": true
   }
}
```
Doing so, Biome won’t emit diagnostics for file that it doesn’t know how to handle.

Add a new "javascript" option to support the unsafe/experimental parameter decorators:

{
   "javascript": {
      "parser": {
         "unsafeParameterDecoratorsEnabled": true
      }
   }
}

Add a new "extends" option, useful to split the configuration file in multiple files:
```
{
  "extends": ["../sharedFormatter.json", "linter.json"]
}
```
The resolution of the files is file system based, Biome doesn’t know how to resolve dependencies yet.
The commands biome check and biome lint now show the remaining diagnostics even when --apply-safe or --apply-unsafe are passed.
Fix the commands biome check and biome lint, they won’t exit with an error code if no error diagnostics are emitted.
Add a new option --error-on-warnings, which instructs Biome to exit with an error code when warnings are emitted.
Terminal window
```
biome check --error-on-warnings ./src
```

Add a configuration to enable parsing comments inside JSON files:

{
  "json": {
    "parser": {
      "allowComments": true
    }
  }
}

Editors

Other changes

The Biome LSP can now show diagnostics belonging to JSON lint rules.
The Biome LSP no longer applies unsafe quickfixes on-save when editor.codeActionsOnSave.quickfix.biome is enabled.
Fix #4564; files too large don’t emit errors.
The Biome LSP sends client messages when files are ignored or too big.

Formatter

Add a new option called --jsx-quote-style.

This option lets you choose between single and double quotes for JSX attributes.
Add the option --arrow-parentheses.

This option allows setting the parentheses style for arrow functions.
The JSON formatter can now format .json files with comments.

Linter

Removed rules

Remove complexity/noExtraSemicolon (#4553)

The Biome formatter takes care of removing extra semicolons. Thus, there is no need for this rule.
Remove useCamelCase

Use useNamingConvention instead.

New rules

Add noExcessiveComplexity
Add useImportRestrictions
Add noFallthroughSwitchClause
Add noGlobalIsFinite

This rule recommends using Number.isFinite instead of the global and unsafe isFinite that attempts a type coercion.
Add noGlobalIsNan

This rule recommends using Number.isNaN instead of the global and unsafe isNaN that attempts a type coercion.
Add noUnsafeDeclarationMerging

This rule disallows declaration merging between an interface and a class.
Add noUselessThisAlias

This rule disallows useless aliasing of this in arrow functions.
Add useArrowFunction

This rule proposes turning function expressions into arrow functions. Function expressions that use this are ignored.
Add noDuplicateJsonKeys

This rule disallow duplicate keys in a JSON object.
Add noVoid

This rule disallows the use of void.
Add noNonoctalDecimalEscape

This rule disallows \8 and \9 escape sequences in string literals.
Add noUselessEmptyExport

This rule disallows useless export {}.
Add useIsArray

This rule proposes using Array.isArray() instead of instanceof Array.
Add useGetterReturn

This rule enforces the presence of non-empty return statements in getters. This makes the following code incorrect:
```
class Person {
    get firstName() {}
}
```

Promoted rules

New rules are promoted, please check #4750 for more details:

The following rules are now recommended:

**- noUselessFragments

Other changes

Add new TypeScript globals (AsyncDisposable, Awaited, DecoratorContext, and others) 4643.
noRedeclare: allow redeclare of index signatures are in different type members #4478

Improve noConsoleLog, noGlobalObjectCalls, useIsNan, and useNumericLiterals by handling globalThis and window namespaces.

For instance, the following code is now reported by noConsoleLog:

globalThis.console.log("log")

Improve noDuplicateParameters to manage constructor parameters.
Improve noInnerDeclarations

Now, the rule doesn’t report false-positives about ambient TypeScript declarations. For example, the following code is no longer reported by the rule:
```
declare var foo;
```
Improve useEnumInitializers

The rule now reports all uninitialized members of an enum in a single diagnostic.

Moreover, ambient enum declarations are now ignored. This avoids reporting ambient enum declarations in TypeScript declaration files.
```
declare enum Weather {
  Rainy,
  Sunny,
}
```
Relax noBannedTypes and improve documentation

The rule no longer reports a user type that reuses a banned type name. The following code is now allowed:
```
import { Number } from "a-lib";
declare const v: Number;
```
The rule now allows the use of the type {} to denote a non-nullable generic type:
```
function f<T extends {}>(x: T) {
    assert(x != null);
}
```
And in a type intersection for narrowing a type to its non-nullable equivalent type:
```
type NonNullableMyType = MyType & {};
```
Improve noConstantCondition

The rule now allows while(true). This recognizes a common pattern in the web community:
```
while (true) {
  if (cond) {
    break;
  }
}
```
Improve the diagnostic and the code action of useDefaultParameterLast.

The diagnostic now reports the last required parameter which should precede optional and default parameters.

The code action now removes any whitespace between the parameter name and its initialization.
Relax noConfusingArrow

All arrow functions that enclose its parameter with parenthesis are allowed. Thus, the following snippet no longer trigger the rule:
```
var x = (a) => 1 ? 2 : 3;
```
The following snippet still triggers the rule:
```
var x = a => 1 ? 2 : 3;
```
Relax useLiteralEnumMembers

Enum members that refer to previous enum members are now allowed. This allows a common pattern in enum flags like in the following example:
```
enum FileAccess {
  None = 0,
  Read = 1,
  Write = 1 << 1,
  All = Read | Write,
}
```
Arbitrary numeric constant expressions are also allowed:
```
enum FileAccess {
  None = 0,
  Read = 2**0,
  Write = 2**1,
  All = Read | Write,
}
```
Improve useLiteralKeys.

Now, the rule suggests simplifying computed properties to string literal properties:
```
{
  ["1+1"]: 2,
  "1+1": 2,
}
```
It also suggests simplifying string literal properties to static properties:
```
{
  "a": 0,
  a: 0,
}
```
These suggestions are made in object literals, classes, interfaces, and object types.
Improve noNewSymbol.

The rule now handles cases where Symbol is namespaced with the global globalThis or window.

The rules useExhaustiveDependencies and useHookAtTopLevel accept a different shape of options

Old configuration:

{
  "linter": {
     "rules": {
        "nursery": {
           "useExhaustiveDependencies": {
              "level": "error",
              "options": {
                 "hooks": [
                    ["useMyEffect", 0, 1]
                 ]
              }
           }
        }
     }
  }
}

New configuration:

{
  "linter": {
     "rules": {
        "nursery": {
           "useExhaustiveDependencies": {
              "level": "error",
              "options": {
                 "hooks": [
                    {
                       "name": "useMyEffect",
                       "closureIndex": 0,
                       "dependenciesIndex": 1
                    }
                 ]
              }
           }
        }
     }
  }
}

noRedundantUseStrict check only 'use strict' directive to resolve false positive diagnostics.

React introduced new directives, “use client” and “use server”. The rule raises false positive errors about these directives.
Fix a crash in the NoParameterAssign rule that occurred when there was a bogus binding. #4323
Fix useExhaustiveDependencies in the following cases #4330:
- when the first argument of hooks is a named function
- inside an export default function
- for React.use hooks
Fix noInvalidConstructorSuper that erroneously reported generic parents #4624.
Fix noDuplicateCase that erroneously reported as equals the strings literals "'" and '"' #4706.
Fix NoUnreachableSuper’s false positive diagnostics (#4483) caused to nested if statement.

The rule no longer reports This constructor calls super() in a loop when using nested if statements in a constructor.
Fix useHookAtTopLevel’s false positive diagnostics (#4637)

The rule no longer reports false positive diagnostics when accessing properties directly from a hook and calling a hook inside function arguments.
Fix noUselessConstructor which erroneously reported constructors with default parameters rome#4781
Fix noUselessFragments’s panics when running biome check --apply-unsafe (#4637)

This rule’s code action emits an invalid AST, so I fixed using JsxString instead of JsStringLiteral
Fix noUndeclaredVariables’s false positive diagnostics (#4675)

The semantic analyzer no longer handles this reference identifier.
Fix noUnusedVariables’s false positive diagnostics (#4688)

The semantic analyzer handles ts export declaration clause correctly.

Parser

Add support for decorators in class method parameters, example:

class AppController {
   get(@Param() id) {}
   // ^^^^^^^^ new supported syntax
}

This syntax is only supported via configuration, because it’s a non-standard syntax.

{
   "javascript": {
      "parser": {
         "unsafeParameterDecoratorsEnabled": true
      }
   }
}

Add support for parsing comments inside JSON files:

{
  "json": {
    "parser": {
      "allowComments": true
    }
  }
}

Add support for the new using syntax
```
const using = resource.lock();
```