@biomejs/biome
Advanced tools
Changelog
1.2.1 (2023-09-15)
json.formatter
properties weren't transformed in camel case.Changelog
1.2.0 (2023-09-15)
--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
--errors-on-warning
didn't work when running biome ci
command.json.formatter.enabled
json.formatter.indentStyle
json.formatter.indentSize
json.formatter.lineWidth
javascript.formatter.enabled
javascript.formatter.indentStyle
javascript.formatter.indentSize
javascript.formatter.lineWidth
New rules are incubated in the nursery group. Once stable, we promote them to a stable group. The following rules are promoted:
void
type. Contributed by @shulandmimiRemove 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
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
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
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.
Changelog
1.1.2 (2023-09-07)
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
Changelog
1.1.1 (2023-09-07)
// 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 @ematipicoChangelog
1.1.0 (2023-09-06)
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 @ematipicorome.json
file is found.biome migrate --write
creates biome.json
from rome.json
, but it won't delete the rome.json
file. Contributed
by @ematipicobiome.json
first, then it attempts to use rome.json
.rage
output.// biome-ignore
as suppression comment.// rome-ignore
suppression is deprecated.else
and an if
, if the if
statement is the only statement in the else
block. Contributed by @n-gudeuseTemplate 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.
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
Changelog
1.0.0 (2023-08-28)
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
}
}
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;
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
:
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
:
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
;
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.
biome check --error-on-warnings ./src
Add a configuration to enable parsing comments inside JSON files:
{
"json": {
"parser": {
"allowComments": true
}
}
}
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.
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.
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.
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.
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.
This rule disallow duplicate keys in a JSON object.
Add noVoid
This rule disallows the use of void
.
This rule disallows \8
and \9
escape sequences in string literals.
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() {}
}
New rules are promoted, please check #4750 for more details:
The following rules are now recommended:
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:
React.use
hooksFix 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.
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();