Lint rules

bun lint has 1,021 rules built in. Turn one on in bunfig.toml, or read about it in the terminal with bun lint --explain <rule>.

ESLint

218 rules.

Rule	Description	Default	Fixable
`accessor-pairs`	Require a getter for every setter in objects and classes
`array-callback-return`	Require callbacks of array methods such as `map` and `filter` to return a value		suggestion
`arrow-body-style`	Enforce one style for the braces around arrow function bodies		yes
`block-scoped-var`	Disallow using a `var` outside the block it is declared in
`callback-return`	Require `return` when calling a callback
`camelcase`	Require camelCase names for variables, functions and properties
`capitalized-comments`	Require comments to start with a capital letter, or forbid it		yes
`class-methods-use-this`	Require class methods to use `this`
`complexity`	Enforce a maximum number of branches in a function
`consistent-return`	Require every `return` in a function to have a value, or none of them
`consistent-this`	Enforce one name for variables that hold `this`
`constructor-super`	Require `super()` to be called exactly once in the constructor of a derived class	error
`curly`	Require braces around the bodies of `if`, `else` and loops		yes
`default-case`	Require a `default` case in every `switch`
`default-case-last`	Require `default` to be the last clause of a `switch`
`default-param-last`	Require parameters with a default value to come after the required ones
`dot-notation`	Require `user.name` instead of `user["name"]`		yes
`eqeqeq`	Require `===` and `!==` instead of `==` and `!=`		yes
`for-direction`	Require the update clause of a `for` loop to move the counter toward the end of the loop	error
`func-name-matching`	Require a function expression's name to match the variable or property it is assigned to
`func-names`	Require or disallow names for `function` expressions
`func-style`	Enforce one way to define functions: declarations, or expressions assigned to variables
`getter-return`	Require getters to return a value	error
`global-require`	Require `require()` calls to be at the top level of the module
`grouped-accessor-pairs`	Require the getter and setter of a property to be next to each other
`guard-for-in`	Require the body of a `for...in` loop to be guarded by an `if`
`handle-callback-err`	Require callbacks to use their error parameter
`id-blacklist`	Disallow the identifier names you list (old name of `id-denylist`)
`id-denylist`	Disallow the identifier names you list
`id-length`	Enforce a minimum and a maximum length for identifier names
`id-match`	Require identifier names to match a regular expression
`init-declarations`	Require or disallow a value in variable declarations
`logical-assignment-operators`	Require or disallow the logical assignment operators `\|\|=`, `&&=` and `??=`		yes
`max-classes-per-file`	Enforce a maximum number of classes per file
`max-depth`	Enforce a maximum depth that blocks can be nested
`max-lines`	Enforce a maximum number of lines per file
`max-lines-per-function`	Enforce a maximum number of lines in a function
`max-nested-callbacks`	Enforce a maximum depth that callbacks can be nested
`max-params`	Enforce a maximum number of parameters in function definitions
`max-statements`	Enforce a maximum number of statements in a function
`new-cap`	Require constructor names to begin with a capital letter
`no-alert`	Disallow `alert`, `confirm`, and `prompt`
`no-array-constructor`	Disallow `Array` constructors in favor of array literals		yes
`no-async-promise-executor`	Disallow an async function as a Promise executor	error
`no-await-in-loop`	Disallow `await` inside of loops
`no-bitwise`	Disallow bitwise operators
`no-buffer-constructor`	Disallow the deprecated `Buffer()` constructor
`no-caller`	Disallow `arguments.caller` and `arguments.callee`
`no-case-declarations`	Disallow `let`, `const`, `function` and `class` declarations directly in a `case` clause	warn	suggestion
`no-catch-shadow`	Disallow a `catch` parameter with the name of a variable in the scope around it
`no-class-assign`	Disallow assigning to the name of a class	error
`no-compare-neg-zero`	Disallow comparing against `-0`	error	suggestion
`no-cond-assign`	Disallow assignments in the test of `if`, loops and `? :`	warn
`no-console`	Disallow the use of `console`		suggestion
`no-const-assign`	Disallow reassigning `const`, `using` and `await using` variables	error
`no-constant-binary-expression`	Disallow comparisons and `&&`, `\|\|`, `??` that always give the same result	error
`no-constant-condition`	Disallow conditions that are always truthy or always falsy	warn
`no-constructor-return`	Disallow returning a value from a constructor
`no-continue`	Disallow `continue` statements
`no-control-regex`	Disallow control characters in regular expressions	warn
`no-debugger`	Disallow `debugger` statements	error
`no-delete-var`	Disallow `delete` on variables	warn
`no-div-regex`	Disallow regular expressions that start with `=`		yes
`no-dupe-args`	Disallow two parameters with the same name in a function	error
`no-dupe-class-members`	Disallow two class members with the same name	error
`no-dupe-else-if`	Disallow an `else if` with a condition that an earlier branch already covers	error
`no-dupe-keys`	Disallow two keys with the same name in an object literal	error
`no-duplicate-case`	Disallow two `case` labels with the same test in a `switch`	error
`no-duplicate-imports`	Disallow importing from the same module more than once in a file
`no-else-return`	Disallow `else` after an `if` branch that always returns		yes
`no-empty`	Disallow empty block statements	warn	suggestion
`no-empty-character-class`	Disallow empty character classes `[]` in regular expressions	warn
`no-empty-function`	Disallow functions with an empty body		suggestion
`no-empty-pattern`	Disallow destructuring patterns that bind nothing	warn
`no-empty-static-block`	Disallow empty `static {}` blocks in classes	warn	suggestion
`no-eq-null`	Disallow comparing with `null` using `==` or `!=`
`no-eval`	Disallow `eval()`
`no-ex-assign`	Disallow assigning to the error parameter of a `catch` clause	warn
`no-extend-native`	Disallow adding properties to the prototypes of built-in objects
`no-extra-bind`	Disallow `.bind()` on functions that do not use `this`		yes
`no-extra-boolean-cast`	Disallow `!!` and `Boolean()` where the value is converted to a boolean anyway	warn	yes
`no-extra-label`	Disallow labels on `break` and `continue` that name the innermost loop or `switch`		yes
`no-fallthrough`	Disallow `case` clauses that run on into the next one	error
`no-func-assign`	Disallow assigning to the name of a function declaration	error
`no-global-assign`	Disallow assigning to built-in and other read-only global variables	warn
`no-implicit-coercion`	Require `Boolean()`, `Number()` and `String()` instead of operator tricks like `!!x` and `+x`		yes
`no-implicit-globals`	Disallow declarations and assignments that create global variables by accident
`no-implied-eval`	Disallow passing a string of code to `setTimeout()`, `setInterval()` or `execScript()`
`no-import-assign`	Disallow assigning to imported bindings	error
`no-inline-comments`	Disallow comments on the same line as code
`no-inner-declarations`	Disallow `function` and, optionally, `var` declarations in nested blocks
`no-invalid-regexp`	Disallow invalid patterns and flags in `RegExp()` and `new RegExp()`	error
`no-invalid-this`	Disallow `this` where its value is `undefined`
`no-irregular-whitespace`	Disallow whitespace characters other than the ordinary space, tab and line break	error
`no-iterator`	Disallow the `__iterator__` property
`no-label-var`	Disallow labels that share a name with a variable
`no-labels`	Disallow labeled statements
`no-lone-blocks`	Disallow blocks that do nothing
`no-lonely-if`	Require `else if` instead of an `if` alone in an `else` block		yes
`no-loop-func`	Disallow functions in loops that use a variable the loop changes
`no-loss-of-precision`	Disallow number literals that cannot be stored exactly as written	error
`no-magic-numbers`	Require numbers to be given a name instead of being used directly
`no-misleading-character-class`	Disallow characters made of several code points inside a regular expression character class	error	suggestion
`no-mixed-requires`	Disallow `require` calls mixed with other variables in one declaration
`no-multi-assign`	Disallow chained assignments such as `a = b = c`
`no-multi-str`	Disallow strings that continue on the next line with a backslash
`no-native-reassign`	Disallow assignments to built-in and other read-only global variables
`no-negated-condition`	Disallow negated conditions in `if`/`else` and in ternaries
`no-negated-in-lhs`	Disallow negating the left operand of `in`
`no-nested-ternary`	Disallow a ternary inside the branch of another ternary
`no-new`	Disallow `new` when the created object is thrown away
`no-new-func`	Disallow creating functions from strings with `Function`
`no-new-native-nonconstructor`	Disallow `new Symbol()` and `new BigInt()`	error
`no-new-object`	Disallow `new Object()` in favor of `{}`
`no-new-require`	Disallow `new require(..)`
`no-new-symbol`	Disallow `new Symbol()`
`no-new-wrappers`	Disallow `new String()`, `new Number()` and `new Boolean()`
`no-nonoctal-decimal-escape`	Disallow the `\8` and `\9` escapes in strings	warn	suggestion
`no-obj-calls`	Disallow calling `Math`, `JSON`, `Reflect`, `Atomics`, `Intl` and `Temporal` as functions	error
`no-object-constructor`	Disallow `Object()` and `new Object()` without an argument		suggestion
`no-octal`	Disallow number literals that start with `0` followed by a digit	warn
`no-octal-escape`	Disallow octal escape sequences such as `\251` in strings
`no-param-reassign`	Disallow assigning to function parameters
`no-path-concat`	Disallow building paths with `+` from `__dirname` or `__filename`
`no-plusplus`	Disallow the `++` and `--` operators
`no-process-env`	Disallow `process.env`
`no-process-exit`	Disallow calls to `process.exit()`
`no-promise-executor-return`	Disallow returning a value from the function passed to `new Promise`		suggestion
`no-proto`	Disallow the `__proto__` property
`no-prototype-builtins`	Disallow calling `hasOwnProperty` and other `Object.prototype` methods on the object itself	warn	suggestion
`no-redeclare`	Disallow declaring the same variable twice in one scope	warn
`no-regex-spaces`	Disallow several spaces in a row in a regular expression	warn	yes
`no-restricted-exports`	Disallow the export names you list, or default exports
`no-restricted-globals`	Disallow the global variables you list
`no-restricted-imports`	Disallow importing the modules, or the names from them, that you list
`no-restricted-modules`	Disallow loading the modules you list with `require()`
`no-restricted-properties`	Disallow the object properties you list
`no-restricted-syntax`	Disallow the syntax you describe with selectors
`no-return-assign`	Disallow assignments in `return` statements
`no-return-await`	Disallow `return await` where the `await` changes nothing for the caller		suggestion
`no-script-url`	Disallow `javascript:` URLs
`no-self-assign`	Disallow assigning a variable or a property to itself	warn
`no-self-compare`	Disallow comparing a value with itself
`no-sequences`	Disallow the comma operator
`no-setter-return`	Disallow returning a value from a setter	warn
`no-shadow`	Disallow a variable with the same name as one in an outer scope
`no-shadow-restricted-names`	Disallow variables named `undefined`, `NaN`, `Infinity`, `eval`, `arguments` or `globalThis`	warn
`no-sparse-arrays`	Disallow array literals with holes	error
`no-sync`	Disallow methods with a name that ends in `Sync`
`no-template-curly-in-string`	Disallow `${}` placeholders in strings with ordinary quotes
`no-ternary`	Disallow the `? :` operator
`no-this-before-super`	Disallow `this` and `super.x` before `super()` in a constructor	error
`no-throw-literal`	Require `throw` to be given something that can be an `Error`
`no-unassigned-vars`	Disallow `let` and `var` variables that are read but never assigned	warn
`no-undef`	Disallow variables that are not declared anywhere	error
`no-undef-init`	Disallow initializing a variable to `undefined`		yes
`no-undefined`	Disallow the use of `undefined` as a variable
`no-underscore-dangle`	Disallow names that start or end with an underscore
`no-unexpected-multiline`	Disallow lines that look like a new statement but continue the previous one	error
`no-unmodified-loop-condition`	Disallow loop conditions that test variables the loop never changes
`no-unneeded-ternary`	Disallow `? :` where the condition alone says the same		yes
`no-unreachable`	Disallow code after `return`, `throw`, `break`, and `continue` that can never run	warn
`no-unreachable-loop`	Disallow loops with a body that can only run once
`no-unsafe-finally`	Disallow `return`, `throw`, `break`, and `continue` in `finally` blocks	error
`no-unsafe-negation`	Disallow negating the left operand of `in` and `instanceof`	error	suggestion
`no-unsafe-optional-chaining`	Disallow optional chaining where `undefined` throws an error	error
`no-unused-expressions`	Disallow statements that compute a value and throw it away
`no-unused-labels`	Disallow labels that no `break` or `continue` refers to	warn	yes
`no-unused-private-class-members`	Disallow `#private` class members that are never used	warn	suggestion
`no-unused-vars`	Disallow variables, functions, imports, and parameters that are never used	warn	suggestion
`no-use-before-define`	Disallow using a variable, function, or class above the line that declares it
`no-useless-assignment`	Disallow assigning a value to a variable that is never read afterwards	warn
`no-useless-backreference`	Disallow regular expression backreferences that always match the empty string	warn
`no-useless-call`	Disallow `.call()` and `.apply()` where a normal call does the same
`no-useless-catch`	Disallow `catch` clauses that only rethrow the error	warn
`no-useless-computed-key`	Disallow brackets around a property key that is a plain string or number		yes
`no-useless-concat`	Disallow joining two string literals with `+` on the same line
`no-useless-constructor`	Disallow constructors that do what the default constructor does		suggestion
`no-useless-escape`	Disallow backslashes that do not change the meaning of a string or regular expression	warn	suggestion
`no-useless-rename`	Disallow renaming an import, export, or destructured value to the same name		yes
`no-useless-return`	Disallow a `return` without a value where the function ends anyway		yes
`no-var`	Require `let` or `const` instead of `var`	warn	yes
`no-void`	Disallow the `void` operator
`no-warning-comments`	Disallow comments that start with `TODO`, `FIXME`, or another term you choose
`no-with`	Disallow `with` statements	warn
`object-shorthand`	Require or disallow the short forms `{ name }` and `{ save() {} }` in object literals		yes
`one-var`	Require variables to be declared in one statement, or in one statement each		yes
`operator-assignment`	Require or disallow shorthand assignment operators such as `+=`		yes
`prefer-arrow-callback`	Require arrow functions for callbacks		yes
`prefer-const`	Require `const` for variables that are never reassigned	warn	yes
`prefer-destructuring`	Require destructuring to read a property or an element into a variable		yes
`prefer-exponentiation-operator`	Require the `**` operator instead of `Math.pow()`		yes
`prefer-named-capture-group`	Require capture groups in regular expressions to have a name		suggestion
`prefer-numeric-literals`	Require binary, octal and hexadecimal literals instead of `parseInt()` on a fixed string		yes
`prefer-object-has-own`	Require `Object.hasOwn()` instead of `Object.prototype.hasOwnProperty.call()`		yes
`prefer-object-spread`	Require object spread instead of `Object.assign()` into a new object		yes
`prefer-promise-reject-errors`	Require an `Error` object as the reason of a promise rejection
`prefer-reflect`	Require `Reflect` methods instead of their older `Object` and `Function` forms
`prefer-regex-literals`	Require regular expression literals instead of `RegExp()` with a fixed pattern		suggestion
`prefer-rest-params`	Require rest parameters instead of `arguments`	warn
`prefer-spread`	Require spread syntax instead of `.apply()` to pass an array as arguments	warn
`prefer-template`	Require template literals instead of string concatenation		yes
`preserve-caught-error`	Require the caught error as the `cause` of a new error thrown in `catch`	warn	suggestion
`radix`	Require the radix argument of `parseInt()`		suggestion
`require-atomic-updates`	Disallow assignments that use a value read before an `await` or a `yield`
`require-await`	Disallow async functions that never use `await`		suggestion
`require-unicode-regexp`	Require the `u` or `v` flag on regular expressions		suggestion
`require-yield`	Require generator functions to contain `yield`	warn
`sort-imports`	Enforce sorted `import` declarations and sorted names inside them		yes
`sort-keys`	Require the keys of object literals to be sorted
`sort-vars`	Require the variables of one declaration to be sorted		yes
`strict`	Require or disallow `"use strict"` directives		yes
`symbol-description`	Require a description when creating a `Symbol`
`unicode-bom`	Require or disallow a Unicode byte order mark at the start of a file		yes
`use-isnan`	Require `Number.isNaN()` instead of a comparison with `NaN`	error	suggestion
`valid-typeof`	Require `typeof` to be compared with a valid type name	error	suggestion
`vars-on-top`	Require `var` declarations at the top of their function or file
`yoda`	Require or disallow comparisons with the literal on the left		yes

typescript-eslint

137 rules.

Rule	Description	Default	Fixable	Needs types
`@typescript-eslint/adjacent-overload-signatures`	Require the overloads of a function to be next to each other
`@typescript-eslint/array-type`	Require either `T[]` or `Array<T>` for array types, consistently		yes
`@typescript-eslint/await-thenable`	Disallow `await` on a value that is not a promise		suggestion	yes
`@typescript-eslint/ban-ts-comment`	Disallow `@ts-ignore` and `@ts-nocheck`, and require a reason after `@ts-expect-error`	warn	suggestion
`@typescript-eslint/ban-tslint-comment`	Disallow `// tslint:disable` and `// tslint:enable` comments		yes
`@typescript-eslint/ban-types`	Disallow `String`, `Number`, `Object`, `Function`, `{}` and similar types
`@typescript-eslint/class-literal-property-style`	Require constants on a class to be all `readonly` fields or all getters		suggestion
`@typescript-eslint/class-methods-use-this`	Require class methods to use `this`
`@typescript-eslint/consistent-generic-constructors`	Require type arguments on the constructor call or on the type annotation, consistently		yes
`@typescript-eslint/consistent-indexed-object-style`	Require either `Record<K, V>` or an index signature, consistently		yes
`@typescript-eslint/consistent-return`	Require every `return` in a function to return a value, or none of them			yes
`@typescript-eslint/consistent-type-assertions`	Require one style of type assertion: `value as T`, `<T>value`, or none		yes
`@typescript-eslint/consistent-type-definitions`	Require either `interface` or `type` for object types, consistently		yes
`@typescript-eslint/consistent-type-exports`	Require `export type` for exports that are only types		yes	yes
`@typescript-eslint/consistent-type-imports`	Require `import type` for imports that are only used as types		yes
`@typescript-eslint/default-param-last`	Require parameters with a default value, and optional parameters, to come last
`@typescript-eslint/dot-notation`	Require `user.name` instead of `user["name"]`		yes	yes
`@typescript-eslint/explicit-function-return-type`	Require a return type on functions and class methods
`@typescript-eslint/explicit-member-accessibility`	Require `public`, `private` or `protected` on class members		yes
`@typescript-eslint/explicit-module-boundary-types`	Require parameter and return types on exported functions and the methods of exported classes
`@typescript-eslint/init-declarations`	Require or disallow a value in variable declarations
`@typescript-eslint/max-params`	Enforce a maximum number of parameters in function definitions
`@typescript-eslint/member-ordering`	Require a consistent order for the members of classes, interfaces and type literals
`@typescript-eslint/method-signature-style`	Enforce one way to write a method in an interface or type literal		yes
`@typescript-eslint/naming-convention`	Enforce naming conventions for variables, functions, types, members and imports
`@typescript-eslint/no-array-constructor`	Disallow `Array()` and `new Array()` in favor of array literals	warn	yes
`@typescript-eslint/no-array-delete`	Disallow `delete` on an element of an array		suggestion	yes
`@typescript-eslint/no-base-to-string`	Disallow turning an object into a string when the result is `[object Object]`			yes
`@typescript-eslint/no-confusing-non-null-assertion`	Disallow a non-null assertion `!` right before `=`, `==`, `===`, `in` or `instanceof`		suggestion
`@typescript-eslint/no-confusing-void-expression`	Require expressions of type `void` to stand alone as statements		yes	yes
`@typescript-eslint/no-deprecated`	Disallow using code marked as `@deprecated`			yes
`@typescript-eslint/no-dupe-class-members`	Disallow two class members with the same name
`@typescript-eslint/no-duplicate-enum-values`	Disallow two enum members with the same value	warn
`@typescript-eslint/no-duplicate-type-constituents`	Disallow the same type twice in a union or intersection		yes	yes
`@typescript-eslint/no-dynamic-delete`	Disallow `delete` with a computed property key
`@typescript-eslint/no-empty-function`	Disallow functions with an empty body		suggestion
`@typescript-eslint/no-empty-interface`	Disallow interfaces that declare no members		yes
`@typescript-eslint/no-empty-object-type`	Disallow the `{}` type and empty interfaces	warn	suggestion
`@typescript-eslint/no-explicit-any`	Disallow the `any` type	warn	yes
`@typescript-eslint/no-extra-non-null-assertion`	Disallow a non-null assertion that has no effect	warn	yes
`@typescript-eslint/no-extraneous-class`	Disallow classes that are empty, only static, or only a constructor
`@typescript-eslint/no-floating-promises`	Require promises to be awaited, returned, or handled		suggestion	yes
`@typescript-eslint/no-for-in-array`	Disallow `for...in` over an array			yes
`@typescript-eslint/no-generated-empty-object-type`	Disallow type operations that produce the `{}` type			yes
`@typescript-eslint/no-implied-eval`	Disallow passing code as a string to `setTimeout`, `setInterval` and `new Function`			yes
`@typescript-eslint/no-import-type-side-effects`	Require `import type` when every name in an import is marked `type`		yes
`@typescript-eslint/no-inferrable-types`	Disallow type annotations that repeat what the initial value already says		yes
`@typescript-eslint/no-invalid-this`	Disallow `this` where its value is `undefined`
`@typescript-eslint/no-invalid-void-type`	Disallow `void` outside of return types and generic type arguments
`@typescript-eslint/no-loop-func`	Disallow functions in loops that use a variable the loop changes
`@typescript-eslint/no-loss-of-precision`	Disallow number literals that cannot be stored exactly as written
`@typescript-eslint/no-magic-numbers`	Disallow numbers that are used without a name
`@typescript-eslint/no-meaningless-void-operator`	Disallow `void` in front of an expression that has no value to discard		yes	yes
`@typescript-eslint/no-misused-new`	Disallow `new` in a class and `constructor` in an interface	error
`@typescript-eslint/no-misused-promises`	Disallow promises where the code around them cannot handle one			yes
`@typescript-eslint/no-misused-spread`	Disallow `...` on values that do not spread the way they look		suggestion	yes
`@typescript-eslint/no-mixed-enums`	Disallow enums that have both number and string members			yes
`@typescript-eslint/no-namespace`	Disallow TypeScript `namespace` and `module` blocks	warn
`@typescript-eslint/no-non-null-asserted-nullish-coalescing`	Disallow `!` on the left side of `??`		suggestion
`@typescript-eslint/no-non-null-asserted-optional-chain`	Disallow `!` after an optional chain	warn	suggestion
`@typescript-eslint/no-non-null-assertion`	Disallow the non-null assertion `value!`		suggestion
`@typescript-eslint/no-redeclare`	Disallow declaring the same name twice in one scope
`@typescript-eslint/no-redundant-type-constituents`	Disallow members of unions and intersections that change nothing or swallow the rest			yes
`@typescript-eslint/no-require-imports`	Disallow `require()` in favor of `import`
`@typescript-eslint/no-restricted-imports`	Disallow imports of the modules you list, with an exception for type imports
`@typescript-eslint/no-restricted-types`	Disallow the types you list		yes
`@typescript-eslint/no-shadow`	Disallow a declaration that hides one with the same name in an outer scope
`@typescript-eslint/no-this-alias`	Disallow storing `this` in a variable	warn
`@typescript-eslint/no-type-alias`	Disallow `type` aliases, or allow only some kinds of them
`@typescript-eslint/no-unnecessary-boolean-literal-compare`	Disallow comparing a boolean with `true` or `false`		yes	yes
`@typescript-eslint/no-unnecessary-condition`	Disallow conditions that the types say are always true or always false		suggestion	yes
`@typescript-eslint/no-unnecessary-parameter-property-assignment`	Disallow assigning a constructor parameter property to itself
`@typescript-eslint/no-unnecessary-qualifier`	Disallow naming the enclosing namespace or enum where the short name works		yes	yes
`@typescript-eslint/no-unnecessary-template-expression`	Disallow `${}` in a template literal where plain text or the value itself does the same		yes	yes
`@typescript-eslint/no-unnecessary-type-arguments`	Disallow a type argument that is the same as the default of its type parameter		yes	yes
`@typescript-eslint/no-unnecessary-type-assertion`	Disallow `as`, `<T>` and `!` assertions that do not change the type		yes	yes
`@typescript-eslint/no-unnecessary-type-constraint`	Disallow `extends any` and `extends unknown` on a type parameter	warn	suggestion
`@typescript-eslint/no-unnecessary-type-conversion`	Disallow converting a value to the type it already has		suggestion	yes
`@typescript-eslint/no-unnecessary-type-parameters`	Disallow a type parameter that is used only once in a signature		suggestion	yes
`@typescript-eslint/no-unsafe-argument`	Disallow passing a value of type `any` as an argument			yes
`@typescript-eslint/no-unsafe-assignment`	Disallow assigning a value of type `any` to a variable or a property			yes
`@typescript-eslint/no-unsafe-call`	Disallow calling a value of type `any`			yes
`@typescript-eslint/no-unsafe-declaration-merging`	Disallow a class and an interface with the same name	warn
`@typescript-eslint/no-unsafe-enum-assignment`	Disallow giving a plain number or string to a place typed as an enum			yes
`@typescript-eslint/no-unsafe-enum-comparison`	Disallow comparing an enum value with a plain number or string		suggestion	yes
`@typescript-eslint/no-unsafe-function-type`	Disallow the built-in `Function` type	warn
`@typescript-eslint/no-unsafe-member-access`	Disallow reading a property of a value of type `any`			yes
`@typescript-eslint/no-unsafe-return`	Disallow returning a value of type `any` from a function			yes
`@typescript-eslint/no-unsafe-type-assertion`	Disallow type assertions that narrow a type			yes
`@typescript-eslint/no-unsafe-unary-minus`	Require the operand of unary `-` to be a number or a bigint			yes
`@typescript-eslint/no-unused-expressions`	Disallow statements that compute a value and do nothing with it	warn
`@typescript-eslint/no-unused-private-class-members`	Disallow private class members that are never used
`@typescript-eslint/no-unused-vars`	Disallow variables, functions, parameters, imports, and types that are never used	warn	yes
`@typescript-eslint/no-use-before-define`	Disallow using a variable, function, class, enum, or type above the line that declares it
`@typescript-eslint/no-useless-constructor`	Disallow constructors that do what the default constructor does		suggestion
`@typescript-eslint/no-useless-default-assignment`	Disallow default values that can never be used		suggestion	yes
`@typescript-eslint/no-useless-empty-export`	Disallow `export {}` in a file that is already a module		yes
`@typescript-eslint/no-var-requires`	Disallow `const x = require()` in favor of `import`
`@typescript-eslint/no-wrapper-object-types`	Disallow `String`, `Number`, `Boolean`, `BigInt`, `Symbol`, and `Object` as types	warn	yes
`@typescript-eslint/non-nullable-type-assertion-style`	Require `value!` instead of `value as T` when the assertion only removes `null` and `undefined`		yes	yes
`@typescript-eslint/only-throw-error`	Disallow throwing values that are not `Error` objects			yes
`@typescript-eslint/parameter-properties`	Require or disallow parameter properties in class constructors
`@typescript-eslint/prefer-as-const`	Require `as const` instead of repeating a literal as its own type	warn	yes
`@typescript-eslint/prefer-destructuring`	Require destructuring to read a property or an element into a variable		yes	yes
`@typescript-eslint/prefer-enum-initializers`	Require every enum member to have an explicit value		suggestion
`@typescript-eslint/prefer-find`	Require `.find()` instead of `.filter()[0]` to get the first match		suggestion	yes
`@typescript-eslint/prefer-for-of`	Require `for...of` instead of a `for` loop that only uses its index to read the array
`@typescript-eslint/prefer-function-type`	Require a function type instead of an interface or object type with only a call signature		yes
`@typescript-eslint/prefer-includes`	Require `.includes()` instead of comparing `.indexOf()` with `-1`		yes	yes
`@typescript-eslint/prefer-literal-enum-member`	Require enum values to be literals, not computed expressions
`@typescript-eslint/prefer-namespace-keyword`	Require `namespace` instead of `module` to declare a namespace	warn	yes
`@typescript-eslint/prefer-nullish-coalescing`	Require `??` instead of `\|\|` or a ternary to give a default for `null` or `undefined`		suggestion	yes
`@typescript-eslint/prefer-optional-chain`	Require `a?.b` instead of `a && a.b`, `!a \|\| !a.b`, or `(a \|\| {}).b`		yes	yes
`@typescript-eslint/prefer-promise-reject-errors`	Require an `Error` as the reason when a promise is rejected			yes
`@typescript-eslint/prefer-readonly`	Require `readonly` on private members that are only assigned in the constructor		yes	yes
`@typescript-eslint/prefer-readonly-parameter-types`	Require the types of function parameters to be read-only			yes
`@typescript-eslint/prefer-reduce-type-parameter`	Require a type argument on `reduce` instead of a type assertion on the initial value		yes	yes
`@typescript-eslint/prefer-regexp-exec`	Require `pattern.exec(text)` instead of `text.match(pattern)` when there is no `g` flag		yes	yes
`@typescript-eslint/prefer-return-this-type`	Require the return type `this` for a method that returns `this`		yes	yes
`@typescript-eslint/prefer-string-starts-ends-with`	Require `startsWith` and `endsWith` instead of other ways to test the start or end of a string		yes	yes
`@typescript-eslint/prefer-ts-expect-error`	Require `@ts-expect-error` instead of `@ts-ignore`		yes
`@typescript-eslint/promise-function-async`	Require functions that return a promise to be `async`		yes	yes
`@typescript-eslint/related-getter-setter-pairs`	Require the type of a getter to be assignable to the type of its setter			yes
`@typescript-eslint/require-array-sort-compare`	Require a compare function in calls to `sort` and `toSorted` on arrays			yes
`@typescript-eslint/require-await`	Disallow `async` functions that never `await` and do not return a promise		suggestion	yes
`@typescript-eslint/restrict-plus-operands`	Require both operands of `+` to be numbers, bigints, or strings			yes
`@typescript-eslint/restrict-template-expressions`	Disallow values in template literals that do not turn into a useful string			yes
`@typescript-eslint/return-await`	Enforce consistent use of `await` when an `async` function returns a promise		yes	yes
`@typescript-eslint/sort-type-constituents`	Require the members of union and intersection types to be sorted		yes
`@typescript-eslint/strict-boolean-expressions`	Disallow nullable numbers, strings, and booleans, `any`, and always-true values in conditions		suggestion	yes
`@typescript-eslint/strict-void-return`	Disallow passing a function that returns a value where a `void` function is expected		suggestion	yes
`@typescript-eslint/switch-exhaustiveness-check`	Require a `switch` on a union or an enum to have a `case` for every member		suggestion	yes
`@typescript-eslint/triple-slash-reference`	Disallow `/// <reference />` comments where an `import` does the job	warn
`@typescript-eslint/typedef`	Require type annotations in the places you choose
`@typescript-eslint/unbound-method`	Disallow taking a method off its object without binding it			yes
`@typescript-eslint/unified-signatures`	Disallow overloads that can be written as one signature
`@typescript-eslint/use-unknown-in-catch-callback-variable`	Require the parameter of a promise rejection callback to be typed `unknown`		suggestion	yes

React

135 rules.

Rule	Description	Default	Fixable
`react-hooks/capitalized-calls`	Disallow calling a function with a capitalized name from a component or a hook
`react-hooks/component-hook-factories`	Deprecated: reports nothing, and is kept so that older configs still load
`react-hooks/config`	Report an invalid configuration of the React Compiler
`react-hooks/error-boundaries`	Disallow JSX inside a `try` block, where `catch` cannot see rendering errors
`react-hooks/exhaustive-deps`	Require the dependency array of a hook to list every value its callback reads	warn	yes
`react-hooks/exhaustive-effect-dependencies`	Require the dependency array of an effect to match what the effect reads		suggestion
`react-hooks/fbt`	Reserved for problems with `fbt` translations in the React Compiler: reports nothing
`react-hooks/gating`	Validate the directive that puts a compiled component behind a feature flag
`react-hooks/globals`	Disallow reassigning variables declared outside a component or hook during render
`react-hooks/hooks`	Require hooks to be called at the top level of a component or hook, never conditionally
`react-hooks/immutability`	Disallow modifying props, state, and other values that React expects to stay unchanged
`react-hooks/incompatible-library`	Report calls to library APIs that the React Compiler cannot memoize safely
`react-hooks/invariant`	Report code that makes the React Compiler fail one of its internal checks
`react-hooks/memo-dependencies`	Require the dependency list of `useMemo` and `useCallback` to match what the callback reads		suggestion
`react-hooks/memoized-effect-dependencies`	Require the dependencies of an effect to be memoized
`react-hooks/no-deriving-state-in-effects`	Disallow effects that only compute state from props or other state
`react-hooks/preserve-manual-memoization`	Disallow `useMemo` and `useCallback` calls that React Compiler cannot keep memoized
`react-hooks/purity`	Disallow calls such as `Math.random()` and `Date.now()` while a component renders
`react-hooks/refs`	Disallow reading or writing `ref.current` while a component renders
`react-hooks/rule-suppression`	Disallow comments that turn off `rules-of-hooks` or `exhaustive-deps`
`react-hooks/rules-of-hooks`	Require hooks to be called at the top level of a component or a custom hook	error
`react-hooks/set-state-in-effect`	Disallow calling a state setter directly in the body of an effect
`react-hooks/set-state-in-render`	Disallow calling a state setter unconditionally while a component renders
`react-hooks/static-components`	Disallow components that are created while another component renders
`react-hooks/syntax`	Disallow invalid JavaScript in components and hooks, such as assigning to a `const`		suggestion
`react-hooks/todo`	Report valid syntax that the React Compiler does not support yet
`react-hooks/unsupported-syntax`	Disallow syntax that the React Compiler cannot compile, such as `eval()`
`react-hooks/use-memo`	Require `useMemo()` callbacks to take no parameters, be synchronous, and not reassign outer variables
`react-hooks/void-use-memo`	Require `useMemo()` callbacks to return a value, and the value to be used
`react/boolean-prop-naming`	Enforce a naming pattern such as `isOpen` or `hasIcon` for boolean props
`react/button-has-type`	Require an explicit, valid `type` on every `button` element
`react/checked-requires-onchange-or-readonly`	Require `onChange` or `readOnly` on an `input` that has `checked`
`react/default-props-match-prop-types`	Require every entry of `defaultProps` to have a prop type that is not required
`react/destructuring-assignment`	Enforce one style for reading `props`, `state`, and `context`: destructured or not		yes
`react/display-name`	Require every component to have a name that React can show
`react/forbid-component-props`	Disallow chosen props, by default `className` and `style`, on components
`react/forbid-dom-props`	Disallow the props you choose on DOM elements such as `div`
`react/forbid-elements`	Disallow the elements and components you choose
`react/forbid-foreign-prop-types`	Disallow reading the `propTypes` of another component
`react/forbid-prop-types`	Disallow vague prop types such as `any`, `array`, and `object`
`react/forward-ref-uses-ref`	Require a component wrapped in `forwardRef` to take a `ref` parameter		suggestion
`react/function-component-definition`	Enforce one way to write function components: declaration, expression, or arrow function		yes
`react/hook-use-state`	Require `useState` to be destructured into a `[value, setValue]` pair		suggestion
`react/iframe-missing-sandbox`	Require a valid `sandbox` attribute on `iframe` elements
`react/jsx-boolean-value`	Enforce one way to write boolean attributes in JSX: `disabled` or `disabled={true}`		yes
`react/jsx-child-element-spacing`	Disallow a line break between text and an inline element in JSX, where a space may be lost
`react/jsx-closing-bracket-location`	Enforce where the closing bracket of a multiline JSX tag goes		yes
`react/jsx-closing-tag-location`	Enforce that the closing tag of a multiline JSX element lines up with its opening tag		yes
`react/jsx-curly-brace-presence`	Disallow curly braces around plain strings in JSX, or require them		yes
`react/jsx-curly-newline`	Enforce consistent line breaks inside the curly braces of JSX expressions		yes
`react/jsx-curly-spacing`	Enforce or disallow spaces inside the curly braces of JSX attributes and children		yes
`react/jsx-equals-spacing`	Enforce or disallow spaces around the `=` of JSX attributes		yes
`react/jsx-filename-extension`	Restrict the file extensions that may contain JSX
`react/jsx-first-prop-new-line`	Enforce the position of the first prop of a JSX element		yes
`react/jsx-fragments`	Enforce `<>` or `<React.Fragment>` for React fragments		yes
`react/jsx-handler-names`	Enforce naming conventions for event handlers and the props they are passed to
`react/jsx-indent`	Enforce consistent indentation of JSX elements and their children		yes
`react/jsx-indent-props`	Enforce consistent indentation of JSX props		yes
`react/jsx-key`	Require a `key` prop on elements in arrays and iterators	error
`react/jsx-max-depth`	Enforce a maximum depth of nested JSX elements
`react/jsx-max-props-per-line`	Enforce a maximum number of props on one line of a JSX tag		yes
`react/jsx-newline`	Require or disallow an empty line between JSX elements and expressions		yes
`react/jsx-no-bind`	Disallow `.bind()` and functions created during render as JSX props
`react/jsx-no-comment-textnodes`	Disallow `//` and `/* */` comments written as text between JSX tags
`react/jsx-no-constructed-context-values`	Disallow context provider values that are created anew on every render
`react/jsx-no-duplicate-props`	Disallow the same prop twice on one JSX element
`react/jsx-no-leaked-render`	Disallow `&&` conditions in JSX that can render `0` or `NaN`		yes
`react/jsx-no-literals`	Disallow text written directly in JSX
`react/jsx-no-script-url`	Disallow `javascript:` URLs in links
`react/jsx-no-target-blank`	Require `rel="noreferrer"` on links that open in a new tab		yes
`react/jsx-no-undef`	Disallow components in JSX that are not declared or imported
`react/jsx-no-useless-fragment`	Disallow fragments that wrap a single child or sit directly in an HTML element		yes
`react/jsx-one-expression-per-line`	Require each child of a JSX element to be on its own line		yes
`react/jsx-pascal-case`	Require component names in JSX to be in PascalCase
`react/jsx-props-no-multi-spaces`	Disallow more than one space, or an empty line, between JSX props		yes
`react/jsx-props-no-spread-multi`	Disallow spreading the same variable twice in one JSX element		yes
`react/jsx-props-no-spreading`	Disallow `{...props}` in JSX
`react/jsx-sort-default-props`	Require the keys of `defaultProps` to be sorted alphabetically
`react/jsx-sort-props`	Require JSX props to be sorted alphabetically		yes
`react/jsx-tag-spacing`	Enforce spacing around the `<`, `/` and `>` of JSX tags		yes
`react/jsx-uses-react`	Count `React` as used in files that contain JSX	error
`react/jsx-uses-vars`	Count a variable as used when it is the name of a JSX tag
`react/jsx-wrap-multilines`	Require parentheses around JSX that spans several lines		yes
`react/no-access-state-in-setstate`	Disallow reading `this.state` in the argument of `this.setState()`
`react/no-adjacent-inline-elements`	Disallow inline elements that touch each other without whitespace between them
`react/no-array-index-key`	Disallow the index of an array item as its `key`
`react/no-arrow-function-lifecycle`	Disallow arrow functions in class fields as React lifecycle methods		yes
`react/no-children-prop`	Disallow passing `children` as a prop
`react/no-clone-element`	Disallow `React.cloneElement`
`react/no-danger`	Disallow the `dangerouslySetInnerHTML` prop
`react/no-danger-with-children`	Disallow `dangerouslySetInnerHTML` on an element that also has children
`react/no-deprecated`	Disallow React APIs that are deprecated
`react/no-did-mount-set-state`	Disallow `this.setState()` in `componentDidMount`
`react/no-did-update-set-state`	Disallow `this.setState()` in `componentDidUpdate`
`react/no-direct-mutation-state`	Disallow assigning to `this.state` outside of the constructor
`react/no-find-dom-node`	Disallow `findDOMNode`
`react/no-invalid-html-attribute`	Disallow values of the `rel` attribute that HTML does not define		suggestion
`react/no-is-mounted`	Disallow `this.isMounted()`
`react/no-multi-comp`	Disallow more than one React component in a file
`react/no-namespace`	Disallow namespaced element names such as `<svg:circle>`
`react/no-object-type-as-default-prop`	Disallow objects, arrays, and functions as default values of destructured props
`react/no-react-children`	Disallow the `React.Children` methods
`react/no-redundant-should-component-update`	Disallow `shouldComponentUpdate` in a class that extends `React.PureComponent`
`react/no-render-return-value`	Disallow using the return value of `ReactDOM.render`
`react/no-set-state`	Disallow `this.setState` in class components
`react/no-string-refs`	Disallow strings as the value of the `ref` attribute
`react/no-this-in-sfc`	Disallow `this` in function components
`react/no-typos`	Disallow misspelled lifecycle methods, static properties, and prop types
`react/no-unescaped-entities`	Disallow `"` and `'` as plain characters in JSX text		suggestion
`react/no-unknown-property`	Disallow attributes on DOM elements that React does not know		yes
`react/no-unsafe`	Disallow the `UNSAFE_` lifecycle methods of class components
`react/no-unstable-nested-components`	Disallow defining a component inside another component
`react/no-unused-class-component-methods`	Disallow methods and properties of a class component that the class never uses
`react/no-unused-prop-types`	Disallow props that are declared but never used in the component
`react/no-unused-state`	Disallow fields of a class component's state that are never read
`react/no-will-update-set-state`	Disallow `this.setState` in `componentWillUpdate`
`react/only-export-components`	Require files with components to export only components, so Fast Refresh works
`react/prefer-es6-class`	Enforce one way to write class components: `class` or `createReactClass`
`react/prefer-exact-props`	Require `propTypes` to be wrapped in a function that rejects unknown props
`react/prefer-function-component`	Require function components instead of class components
`react/prefer-read-only-props`	Require the props in a component's type to be `readonly`		yes
`react/prefer-stateless-function`	Require class components that only render from props to be functions
`react/prop-types`	Require every prop that a component uses to be declared
`react/react-in-jsx-scope`	Require `React` to be in scope in files that use JSX
`react/require-default-props`	Require a default value for every prop that is not required
`react/require-optimization`	Require class components to define `shouldComponentUpdate` or extend `PureComponent`
`react/require-render-return`	Require the `render` method of a class component to return something
`react/self-closing-comp`	Require elements without children to be self-closing		yes
`react/sort-comp`	Enforce the order of methods and properties in a class component
`react/sort-default-props`	Require the keys of `defaultProps` to be sorted alphabetically
`react/sort-prop-types`	Require the keys of `propTypes` to be sorted alphabetically		yes
`react/state-in-constructor`	Enforce where a class component sets its initial state: in the constructor or in a class field
`react/static-property-placement`	Enforce where a class component declares `propTypes`, `defaultProps` and other static properties
`react/style-prop-object`	Require the value of the `style` prop to be an object
`react/void-dom-elements-no-children`	Disallow children on void DOM elements such as `<img />` and `<br />`

React performance

4 rules.

Rule	Description	Default	Fixable	Needs types
`react-perf/jsx-no-jsx-as-prop`	Disallow JSX elements created during render as the value of a JSX prop
`react-perf/jsx-no-new-array-as-prop`	Disallow arrays created during render as the value of a JSX prop
`react-perf/jsx-no-new-function-as-prop`	Disallow functions created during render as the value of a JSX prop
`react-perf/jsx-no-new-object-as-prop`	Disallow objects created during render as the value of a JSX prop

36 rules.

Rule	Description	Fixable
`jsx-a11y/alt-text`	Require alternative text on `img`, `area`, `object` and `input type="image"`
`jsx-a11y/anchor-ambiguous-text`	Disallow link text such as "click here" that says nothing about the target
`jsx-a11y/anchor-has-content`	Require links to have content that a screen reader can read	yes
`jsx-a11y/anchor-is-valid`	Require links to have a real `href`, and buttons to be `button` elements
`jsx-a11y/aria-activedescendant-has-tabindex`	Require elements with `aria-activedescendant` to be focusable
`jsx-a11y/aria-props`	Disallow `aria-*` attributes that do not exist	yes
`jsx-a11y/aria-proptypes`	Require `aria-*` attributes to have a value of the right kind
`jsx-a11y/aria-role`	Require `role` to be a real ARIA role that is not abstract
`jsx-a11y/aria-unsupported-elements`	Disallow `role` and `aria-*` attributes on elements that do not support them	yes
`jsx-a11y/autocomplete-valid`	Require `autoComplete` on an `input` to be a value that browsers know
`jsx-a11y/click-events-have-key-events`	Require a keyboard handler next to `onClick` on elements that are not controls
`jsx-a11y/control-has-associated-label`	Require buttons, links and other controls to have a text label
`jsx-a11y/heading-has-content`	Require headings to have content that a screen reader can read
`jsx-a11y/html-has-lang`	Require a `lang` attribute on the `html` element
`jsx-a11y/iframe-has-title`	Require a `title` on `iframe` elements
`jsx-a11y/img-redundant-alt`	Disallow the words "image", "photo" and "picture" in `alt` text
`jsx-a11y/interactive-supports-focus`	Require elements with an interactive role and an event handler to be focusable	suggestion
`jsx-a11y/label-has-associated-control`	Require every `<label>` to have text and a form control it belongs to
`jsx-a11y/lang`	Require the `lang` attribute of `<html>` to be a valid language tag
`jsx-a11y/media-has-caption`	Require `<audio>` and `<video>` to have a `<track>` with captions
`jsx-a11y/mouse-events-have-key-events`	Require `onFocus` with `onMouseOver` and `onBlur` with `onMouseOut`
`jsx-a11y/no-access-key`	Disallow the `accessKey` attribute	suggestion
`jsx-a11y/no-aria-hidden-on-focusable`	Disallow `aria-hidden="true"` on elements that can receive focus	yes
`jsx-a11y/no-autofocus`	Disallow the `autoFocus` attribute	suggestion
`jsx-a11y/no-distracting-elements`	Disallow `<marquee>` and `<blink>`
`jsx-a11y/no-interactive-element-to-noninteractive-role`	Disallow non-interactive ARIA roles on interactive elements
`jsx-a11y/no-noninteractive-element-interactions`	Disallow mouse and keyboard handlers on non-interactive elements
`jsx-a11y/no-noninteractive-element-to-interactive-role`	Disallow interactive ARIA roles on non-interactive elements
`jsx-a11y/no-noninteractive-tabindex`	Disallow `tabIndex` of 0 or more on non-interactive elements
`jsx-a11y/no-redundant-roles`	Disallow a `role` that the element already has	yes
`jsx-a11y/no-static-element-interactions`	Require a `role` on `<div>`, `<span>` and similar elements that have event handlers
`jsx-a11y/prefer-tag-over-role`	Require the HTML element instead of a `role` that imitates it
`jsx-a11y/role-has-required-aria-props`	Require the `aria-*` attributes that an element's `role` needs
`jsx-a11y/role-supports-aria-props`	Disallow `aria-*` attributes that the element's role does not support
`jsx-a11y/scope`	Disallow the `scope` attribute on elements other than `<th>`	yes
`jsx-a11y/tabindex-no-positive`	Disallow `tabIndex` values greater than 0	suggestion

Next.js

21 rules.

Rule	Description	Fixable
`@next/next/google-font-display`	Require a `display` parameter other than `auto`, `block` or `fallback` on Google Fonts URLs
`@next/next/google-font-preconnect`	Require `rel="preconnect"` on `<link>` elements that point to `fonts.gstatic.com`
`@next/next/inline-script-id`	Require an `id` on `next/script` components that have inline content
`@next/next/next-script-for-ga`	Require `next/script` instead of `<script>` to load Google Analytics
`@next/next/no-assign-module-variable`	Disallow declaring a variable named `module`
`@next/next/no-async-client-component`	Disallow `async` components in files that start with `"use client"`
`@next/next/no-before-interactive-script-outside-document`	Disallow the `beforeInteractive` strategy of `next/script` outside `pages/_document.js`
`@next/next/no-css-tags`	Disallow `<link rel="stylesheet">` for your own CSS files
`@next/next/no-document-import-in-page`	Disallow importing `next/document` outside `pages/_document.js`
`@next/next/no-duplicate-head`	Disallow more than one `<Head>` element in a file
`@next/next/no-head-element`	Disallow the `<head>` element in favor of `Head` from `next/head`
`@next/next/no-head-import-in-document`	Disallow importing `next/head` in `pages/_document.js`
`@next/next/no-html-link-for-pages`	Disallow `<a>` elements that link to another page of the app
`@next/next/no-img-element`	Disallow the `<img>` element in favor of `Image` from `next/image`
`@next/next/no-page-custom-font`	Disallow Google Fonts `<link>` elements outside `pages/_document.js`
`@next/next/no-script-component-in-head`	Disallow `<Script>` as a child of `Head` from `next/head`
`@next/next/no-styled-jsx-in-document`	Disallow `<style jsx>` in `pages/_document.js`
`@next/next/no-sync-scripts`	Disallow `<script src>` without `async` or `defer`
`@next/next/no-title-in-document-head`	Disallow `<title>` in the `Head` of `next/document`
`@next/next/no-typos`	Disallow misspellings of `getStaticProps`, `getStaticPaths` and `getServerSideProps`	suggestion
`@next/next/no-unwanted-polyfillio`	Disallow scripts from polyfill.io, and polyfills that Next.js already ships

import

46 rules.

Rule	Description	Fixable
`import/consistent-type-specifier-style`	Enforce one way to mark type-only imports: `import type { A }` or `import { type A }`	yes
`import/default`	Require a default import to match a default export in the imported file
`import/dynamic-import-chunkname`	Require a `webpackChunkName` comment in every dynamic `import()`	suggestion
`import/enforce-node-protocol-usage`	Enforce either `node:fs` or `fs` when importing Node.js built-in modules	yes
`import/export`	Disallow exporting the same name twice, and `export *` from a file with no named exports
`import/exports-last`	Require all exports to come after every other statement in the file
`import/extensions`	Enforce that import paths always include the file extension, or never do
`import/first`	Require all imports to come before every other statement in the file	yes
`import/group-exports`	Require all named exports to be in a single `export` declaration
`import/imports-first`	Require all imports to come before every other statement (old name of `import/first`)	yes
`import/max-dependencies`	Enforce a maximum number of modules that a file can import
`import/named`	Require each named import to match a named export in the imported file
`import/namespace`	Require each property read from an `import * as` namespace to be exported by that file
`import/newline-after-import`	Require an empty line between the last import and the code that follows	yes
`import/no-absolute-path`	Disallow importing a module by an absolute file system path	yes
`import/no-amd`	Disallow AMD `define()` and `require()` calls
`import/no-anonymous-default-export`	Disallow default exports that have no name
`import/no-commonjs`	Disallow `require()`, `module.exports` and `exports.*` in favor of `import` and `export`
`import/no-cycle`	Disallow importing a module that imports this file back, directly or through other modules
`import/no-default-export`	Disallow default exports
`import/no-deprecated`	Disallow importing and using names that are marked `@deprecated`
`import/no-duplicates`	Disallow importing the same module more than once in a file	yes
`import/no-dynamic-require`	Disallow `require()` with an argument that is not a string literal
`import/no-empty-named-blocks`	Disallow `import {} from` with nothing between the braces	yes
`import/no-extraneous-dependencies`	Disallow importing a package that `package.json` does not list
`import/no-import-module-exports`	Disallow `import` declarations in a file that exports with `module.exports` or `exports.*`	yes
`import/no-internal-modules`	Disallow importing a file from inside another directory or package
`import/no-mutable-exports`	Disallow exporting a variable declared with `let` or `var`
`import/no-named-as-default`	Disallow naming a default import after a named export of the same module
`import/no-named-as-default-member`	Disallow reading a property of a default import that is also a named export of the module
`import/no-named-default`	Disallow `import { default as name }` in favor of `import name`
`import/no-named-export`	Disallow named exports, so that a module only has a default export
`import/no-namespace`	Disallow `import * as name` in favor of named imports	yes
`import/no-nodejs-modules`	Disallow importing Node.js builtin modules such as `fs` and `path`
`import/no-relative-packages`	Disallow relative imports that reach into another package	yes
`import/no-relative-parent-imports`	Disallow relative imports from parent directories
`import/no-restricted-paths`	Disallow files in one folder from importing files in another
`import/no-self-import`	Disallow a module from importing itself
`import/no-unassigned-import`	Disallow imports that bind no name
`import/no-unresolved`	Require every import to point to a file or package that exists
`import/no-unused-modules`	Disallow exports that no other file imports, and files that export nothing
`import/no-useless-path-segments`	Disallow path segments in imports that can be removed	yes
`import/no-webpack-loader-syntax`	Disallow webpack loader syntax such as `style-loader!./app.css` in imports
`import/order`	Enforce a consistent order of imports, by group and optionally by name	yes
`import/prefer-default-export`	Require a default export in a file that exports a single name
`import/unambiguous`	Require a module to have an `import` or `export` so it cannot be read as a script

unicorn

138 rules.

Rule	Description	Fixable
`unicorn/catch-error-name`	Enforce one name for the error in `catch` clauses and promise handlers	yes
`unicorn/consistent-assert`	Require `assert.ok(value)` instead of `assert(value)` with `node:assert`	yes
`unicorn/consistent-date-clone`	Require `new Date(date)` instead of `new Date(date.getTime())` to copy a date	yes
`unicorn/consistent-empty-array-spread`	Require both branches of a spread ternary in an array to have the same type	suggestion
`unicorn/consistent-existence-index-check`	Require `=== -1` and `!== -1` to test the result of `indexOf()` and `findIndex()`	yes
`unicorn/consistent-function-scoping`	Require functions that use nothing from the enclosing function to be moved out of it
`unicorn/consistent-template-literal-escape`	Enforce one way to escape `${` in template literals	yes
`unicorn/custom-error-definition`	Enforce that subclasses of `Error` set `name` and pass the message to `super()`
`unicorn/empty-brace-spaces`	Disallow spaces and line breaks inside empty braces	yes
`unicorn/error-message`	Require a message when creating a built-in error
`unicorn/escape-case`	Require uppercase hexadecimal digits in escape sequences	yes
`unicorn/explicit-length-check`	Require `length` and `size` to be compared with a number	yes
`unicorn/explicit-timer-delay`	Require or disallow an explicit delay for `setTimeout()` and `setInterval()`	yes
`unicorn/filename-case`	Enforce one case style for file names
`unicorn/import-style`	Enforce how each module is imported: named, default, namespace, or for side effects
`unicorn/max-nested-calls`	Enforce a maximum depth of calls nested in the arguments of other calls
`unicorn/new-for-builtins`	Require `new` for built-in classes and disallow it for `String`, `Number`, `Boolean`, `Symbol`, `BigInt`
`unicorn/no-abusive-eslint-disable`	Require `eslint-disable` comments to name the rules they turn off
`unicorn/no-accessor-recursion`	Disallow a getter or setter that uses its own property on `this`
`unicorn/no-anonymous-default-export`	Require a name for a function or class that is the default export
`unicorn/no-array-callback-reference`	Disallow passing a function by name to array methods such as `map` and `filter`
`unicorn/no-array-fill-with-reference-type`	Disallow filling an array with one object, array, or class instance
`unicorn/no-array-for-each`	Require a `for...of` loop instead of `.forEach()`
`unicorn/no-array-method-this-argument`	Disallow the `thisArg` argument of array methods such as `map` and `filter`
`unicorn/no-array-reduce`	Disallow `reduce()` and `reduceRight()` in favor of a loop
`unicorn/no-array-reverse`	Require `toReversed()` instead of `reverse()`, which changes the array	suggestion
`unicorn/no-array-sort`	Require `toSorted()` instead of `sort()`, which changes the array	suggestion
`unicorn/no-await-expression-member`	Disallow reading a property directly from an `await` expression	yes
`unicorn/no-await-in-promise-methods`	Disallow `await` on the elements of the array passed to `Promise.all()` and similar methods	suggestion
`unicorn/no-confusing-array-with`	Disallow a negative index and `.length` as the index of `Array#with()`
`unicorn/no-console-spaces`	Disallow spaces at the edges of strings where `console.log()` already adds one	yes
`unicorn/no-document-cookie`	Disallow assigning to `document.cookie`
`unicorn/no-empty-file`	Disallow files that contain no code
`unicorn/no-hex-escape`	Require Unicode escapes such as `\u001B` instead of hexadecimal escapes such as `\x1B`	yes
`unicorn/no-immediate-mutation`	Disallow changing an array, object, `Set`, or `Map` in the statement right after creating it
`unicorn/no-instanceof-array`	Require `Array.isArray()` instead of `instanceof Array`	yes
`unicorn/no-instanceof-builtins`	Disallow `instanceof` with built-in constructors such as `Array`, `String`, and `Function`	suggestion
`unicorn/no-invalid-fetch-options`	Disallow a `body` in `fetch()` and `new Request()` when the method is `GET` or `HEAD`
`unicorn/no-invalid-remove-event-listener`	Disallow passing a new function to `removeEventListener()`
`unicorn/no-length-as-slice-end`	Disallow passing `.length` as the end argument of `.slice()`	yes
`unicorn/no-lonely-if`	Disallow an `if` as the only statement in another `if` when neither has an `else`
`unicorn/no-magic-array-flat-depth`	Disallow an unexplained number as the depth of `.flat()`
`unicorn/no-negated-condition`	Disallow a negated condition in an `if` with an `else` and in a ternary	yes
`unicorn/no-negation-in-equality-check`	Disallow `!` on the left side of `===`, `!==`, `==`, and `!=`	suggestion
`unicorn/no-nested-ternary`	Disallow deeply nested ternaries, and require parentheses around a ternary in a ternary	yes
`unicorn/no-new-array`	Disallow `new Array()` with a single argument	suggestion
`unicorn/no-new-buffer`	Require `Buffer.from()` or `Buffer.alloc()` instead of the deprecated `new Buffer()`	suggestion
`unicorn/no-null`	Disallow the `null` literal in favor of `undefined`	yes
`unicorn/no-object-as-default-parameter`	Disallow an object literal with properties as the default value of a parameter
`unicorn/no-process-exit`	Disallow `process.exit()`
`unicorn/no-single-promise-in-promise-methods`	Disallow an array with one item in `Promise.all()`, `Promise.any()`, and `Promise.race()`	yes
`unicorn/no-static-only-class`	Disallow classes that have only `static` members	yes
`unicorn/no-thenable`	Disallow a `then` property on objects, classes, and module exports
`unicorn/no-this-assignment`	Disallow assigning `this` to a variable
`unicorn/no-typeof-undefined`	Require comparing with `undefined` directly instead of `typeof x === "undefined"`	yes
`unicorn/no-unnecessary-array-flat-depth`	Disallow passing `1` as the depth to `Array#flat()`	suggestion
`unicorn/no-unnecessary-array-splice-count`	Disallow `.length` or `Infinity` as the count of `splice()` and `toSpliced()`	yes
`unicorn/no-unnecessary-await`	Disallow `await` on a value that cannot be a promise	yes
`unicorn/no-unnecessary-slice-end`	Disallow `.length` or `Infinity` as the end of `slice()`	yes
`unicorn/no-unreadable-array-destructuring`	Disallow array destructuring that skips two or more values in a row
`unicorn/no-unreadable-iife`	Disallow calling an arrow function in place when its body is in parentheses	suggestion
`unicorn/no-useless-collection-argument`	Disallow empty arguments and fallbacks in `new Set()`, `Map`, `WeakSet`, and `WeakMap`	suggestion
`unicorn/no-useless-error-capture-stack-trace`	Disallow `Error.captureStackTrace()` in the constructor of an `Error` subclass	suggestion
`unicorn/no-useless-fallback-in-spread`	Disallow an empty object as the fallback when spreading into an object literal	yes
`unicorn/no-useless-iterator-to-array`	Disallow `.toArray()` on an iterator where the iterator itself works	yes
`unicorn/no-useless-length-check`	Disallow checking an array's length next to `.some()` or `.every()` where it changes nothing
`unicorn/no-useless-promise-resolve-reject`	Disallow returning `Promise.resolve()` or `Promise.reject()` from an async function or promise callback	yes
`unicorn/no-useless-spread`	Disallow spreads that only build an array or object to take it apart or copy it again	yes
`unicorn/no-useless-switch-case`	Disallow empty `case` clauses that fall through to the last `default`	suggestion
`unicorn/no-useless-undefined`	Disallow `undefined` where leaving it out means the same	yes
`unicorn/no-zero-fractions`	Disallow numbers with a zero fraction or a dangling dot	yes
`unicorn/number-literal-case`	Require lowercase prefixes and exponents, and uppercase hexadecimal digits, in numbers	yes
`unicorn/numeric-separators-style`	Enforce how digits are grouped with `_` in numbers	yes
`unicorn/prefer-add-event-listener`	Require `addEventListener()` instead of assigning to `on` properties such as `onclick`
`unicorn/prefer-array-find`	Require `.find()` or `.findLast()` instead of taking one element from `.filter()`
`unicorn/prefer-array-flat`	Require `.flat()` instead of flattening an array with `concat`, `reduce` or `flatMap`	yes
`unicorn/prefer-array-flat-map`	Require one `.flatMap()` instead of `.map().flat()` or `.filter().flatMap()`	yes
`unicorn/prefer-array-index-of`	Require `.indexOf()` instead of `.findIndex()` when looking for a value
`unicorn/prefer-array-some`	Require `.some()` to test whether an array has a matching element	suggestion
`unicorn/prefer-at`	Require `.at()` to read an element counted from the end of an array or string	yes
`unicorn/prefer-bigint-literals`	Require `BigInt` literals such as `123n` instead of `BigInt(123)`	yes
`unicorn/prefer-blob-reading-methods`	Require `blob.text()` and `blob.arrayBuffer()` instead of a `FileReader`
`unicorn/prefer-class-fields`	Require class fields instead of `this` assignments of fixed values in the constructor	yes
`unicorn/prefer-classlist-toggle`	Require `classList.toggle()` instead of choosing between `add()` and `remove()`	yes
`unicorn/prefer-code-point`	Require `codePointAt()` and `String.fromCodePoint()` over `charCodeAt()` and `String.fromCharCode()`	yes
`unicorn/prefer-date-now`	Require `Date.now()` to get the current time in milliseconds	yes
`unicorn/prefer-default-parameters`	Require default parameters instead of reassigning a parameter in the function body	suggestion
`unicorn/prefer-dom-node-append`	Require `.append()` instead of `.appendChild()` on DOM nodes	yes
`unicorn/prefer-dom-node-dataset`	Require `.dataset` instead of the attribute methods for `data-*` attributes	yes
`unicorn/prefer-dom-node-remove`	Require `child.remove()` instead of `parent.removeChild(child)`
`unicorn/prefer-dom-node-text-content`	Require `.textContent` instead of `.innerText`	yes
`unicorn/prefer-event-target`	Require `EventTarget` instead of `EventEmitter`
`unicorn/prefer-export-from`	Require `export ... from` to re-export instead of an import and a separate export	suggestion
`unicorn/prefer-global-this`	Require `globalThis` instead of `window`, `self` and `global`	suggestion
`unicorn/prefer-import-meta-properties`	Require `import.meta.dirname` and `import.meta.filename` instead of building them from the URL	yes
`unicorn/prefer-includes`	Require `.includes()` instead of comparing `.indexOf()` with `-1` or `0`	suggestion
`unicorn/prefer-keyboard-event-key`	Require `event.key` instead of `keyCode`, `charCode` and `which`	yes
`unicorn/prefer-logical-operator-over-ternary`	Require `\|\|` or `??` instead of a ternary that repeats its condition	suggestion
`unicorn/prefer-math-min-max`	Require `Math.min()` and `Math.max()` instead of a ternary that picks the smaller or larger value	suggestion
`unicorn/prefer-math-trunc`	Require `Math.trunc()` instead of bitwise tricks to drop the fraction of a number	suggestion
`unicorn/prefer-modern-dom-apis`	Require `.before()`, `.after()`, `.append()`, `.prepend()` and `.replaceWith()` over older DOM methods	suggestion
`unicorn/prefer-modern-math-apis`	Require `Math.log10()`, `Math.log2()`, `Math.hypot()` and `Math.abs()` over hand-written formulas
`unicorn/prefer-module`	Require ES modules instead of CommonJS
`unicorn/prefer-native-coercion-functions`	Require passing `String`, `Number`, `BigInt`, `Boolean` and `Symbol` directly instead of wrapping them
`unicorn/prefer-negative-index`	Require a negative index instead of `.length - index`	yes
`unicorn/prefer-node-protocol`	Require the `node:` prefix when importing Node.js built-in modules	yes
`unicorn/prefer-number-coercion`	Require `Number()` instead of `parseFloat()` and base-10 `parseInt()`	suggestion
`unicorn/prefer-number-properties`	Require `Number.isNaN`, `Number.parseInt` and the like instead of the globals	yes
`unicorn/prefer-object-from-entries`	Require `Object.fromEntries()` to turn key-value pairs into an object
`unicorn/prefer-optional-catch-binding`	Require `catch {}` without a parameter when the error is not used	yes
`unicorn/prefer-prototype-methods`	Require borrowing a method from the prototype instead of from an empty `[]` or `{}`	yes
`unicorn/prefer-query-selector`	Require `querySelector()` and `querySelectorAll()` instead of the `getElement...` methods	yes
`unicorn/prefer-reflect-apply`	Require `Reflect.apply()` instead of `Function.prototype.apply()`	suggestion
`unicorn/prefer-regexp-test`	Require `RegExp#test()` instead of `String#match()` and `RegExp#exec()` for a yes or no answer	yes
`unicorn/prefer-response-static-json`	Require `Response.json()` instead of `new Response(JSON.stringify())`	suggestion
`unicorn/prefer-set-has`	Require `Set#has()` instead of `Array#includes()` for an array that is only searched	yes
`unicorn/prefer-set-size`	Require `Set#size` instead of converting the `Set` to an array to read `length`	yes
`unicorn/prefer-single-call`	Require one call instead of several in a row to `push()`, `unshift()`, `classList.add()` and the like	yes
`unicorn/prefer-spread`	Require the spread operator instead of `Array.from()`, `concat()`, `slice()` and `toSpliced()`	yes
`unicorn/prefer-string-raw`	Require `String.raw` for strings that escape backslashes	yes
`unicorn/prefer-string-replace-all`	Require `replaceAll()` instead of `replace()` with a global regex	yes
`unicorn/prefer-string-slice`	Require `slice()` instead of `substr()` and `substring()`	yes
`unicorn/prefer-string-starts-ends-with`	Require `startsWith()` and `endsWith()` instead of a regex with `^` or `$`	yes
`unicorn/prefer-string-trim-start-end`	Require `trimStart()` and `trimEnd()` instead of `trimLeft()` and `trimRight()`	yes
`unicorn/prefer-structured-clone`	Require `structuredClone()` for deep clones	suggestion
`unicorn/prefer-ternary`	Require a ternary instead of an `if`/`else` where both branches do the same kind of thing
`unicorn/prefer-top-level-await`	Require top-level `await` instead of promise chains and async wrappers at the top of a module
`unicorn/prefer-type-error`	Require `TypeError` when the `throw` follows a type check	yes
`unicorn/relative-url-style`	Enforce one style for relative URLs in `new URL()`: with or without `./`	yes
`unicorn/require-array-join-separator`	Require the separator argument of `Array#join()`	yes
`unicorn/require-module-attributes`	Disallow an empty attribute list in `import`, `export` and `import()`	suggestion
`unicorn/require-module-specifiers`	Disallow empty braces in `import` and `export` statements	yes
`unicorn/require-number-to-fixed-digits-argument`	Require the digits argument of `Number#toFixed()`	yes
`unicorn/require-post-message-target-origin`	Require the `targetOrigin` argument of `window.postMessage()`	suggestion
`unicorn/switch-case-braces`	Enforce braces, or no braces, around the body of each `case`	yes
`unicorn/switch-case-break-position`	Require `break`, `return`, `continue` and `throw` inside the braces of a `case`
`unicorn/text-encoding-identifier-case`	Enforce one spelling for the encoding names `utf8` and `ascii`	yes
`unicorn/throw-new-error`	Require `new` when creating an error	yes

promise

16 rules.

Rule	Description	Fixable
`promise/always-return`	Require every `then()` callback to return a value or throw
`promise/avoid-new`	Disallow creating promises with `new Promise()`
`promise/catch-or-return`	Require a promise chain to end with `catch()` or to be returned
`promise/no-callback-in-promise`	Disallow calling a callback inside `then()` or `catch()`
`promise/no-multiple-resolved`	Disallow paths that call `resolve` or `reject` more than once in a `new Promise()` executor
`promise/no-nesting`	Disallow `then()` and `catch()` nested inside another `then()` or `catch()`
`promise/no-new-statics`	Disallow `new` on static `Promise` methods such as `Promise.all`	yes
`promise/no-promise-in-callback`	Disallow promises inside error-first callbacks
`promise/no-return-in-finally`	Disallow `return` in a `finally()` callback
`promise/no-return-wrap`	Disallow returning `Promise.resolve()` or `Promise.reject()` from a promise callback
`promise/param-names`	Require the parameters of a `new Promise()` executor to be named `resolve` and `reject`
`promise/prefer-await-to-callbacks`	Require `async`/`await` instead of error-first callbacks
`promise/prefer-await-to-then`	Require `await` instead of `then()`, `catch()` and `finally()`
`promise/prefer-catch`	Require `catch()` instead of a second argument to `then()`
`promise/spec-only`	Disallow `Promise` static methods that are not part of the language
`promise/valid-params`	Require the right number of arguments for `Promise` methods

Node.js (n)

15 rules.

Rule	Description	Fixable
`n/callback-return`	Require a `return` with every call to a callback
`n/exports-style`	Enforce either `module.exports` or `exports` in CommonJS files
`n/global-require`	Require `require()` calls to be at the top level of the file
`n/handle-callback-err`	Require callbacks to use their error parameter
`n/no-exports-assign`	Disallow assigning to `exports`	yes
`n/no-mixed-requires`	Disallow `require()` calls mixed with other variables in one declaration
`n/no-new-require`	Disallow `new require()`
`n/no-path-concat`	Disallow joining `__dirname` and `__filename` to a path with `+` or a template
`n/no-process-env`	Disallow `process.env`
`n/no-process-exit`	Disallow `process.exit()`
`n/no-sync`	Disallow calls to functions with names that end in `Sync`
`n/no-top-level-await`	Disallow `await` at the top level of a module
`n/no-unsupported-features/es-builtins`	Disallow JavaScript built-ins that the Node.js versions you support do not have
`n/no-unsupported-features/es-syntax`	Disallow JavaScript syntax that the Node.js versions you support do not have
`n/no-unsupported-features/node-builtins`	Disallow Node.js APIs that the Node.js versions you support do not have

oxc

27 rules.

Rule	Description	Fixable
`oxc/approx-constant`	Disallow numbers that approximate a constant of the `Math` object	suggestion
`oxc/bad-array-method-on-arguments`	Disallow calling array methods on the `arguments` object
`oxc/bad-bitwise-operator`	Disallow `&` and `\|` where `&&` and `\|\|` were probably meant	suggestion
`oxc/bad-char-at-comparison`	Disallow comparing a single character with a longer string
`oxc/bad-comparison-sequence`	Disallow chained comparisons such as `a < b < c`
`oxc/bad-match-all-arg`	Require the `g` flag on a regular expression passed to `matchAll()`
`oxc/bad-min-max-func`	Disallow `Math.min` and `Math.max` combinations that always give the same result
`oxc/bad-object-literal-comparison`	Disallow comparing a value with `{}` or `[]`
`oxc/bad-replace-all-arg`	Require the `g` flag on a regular expression passed to `replaceAll()`
`oxc/branches-sharing-code`	Disallow the same statements at the start or end of every branch of an `if`	suggestion
`oxc/const-comparisons`	Disallow comparisons that are always true, always false, or repeated
`oxc/double-comparisons`	Disallow two comparisons of the same values that one operator can express	suggestion
`oxc/erasing-op`	Disallow operations with `0` that erase the other operand	yes
`oxc/misrefactored-assign-op`	Disallow `a += a + b`, where the target is repeated on the right	suggestion
`oxc/missing-throw`	Require `throw` before a `new Error()` that is not used	suggestion
`oxc/no-accumulating-spread`	Disallow spreading the accumulator in `reduce()` and in loops
`oxc/no-async-await`	Disallow `async` functions
`oxc/no-async-endpoint-handlers`	Disallow `async` functions as Express route handlers and middleware
`oxc/no-barrel-file`	Disallow files that load too many modules through `export *`
`oxc/no-const-enum`	Disallow TypeScript `const enum`	yes
`oxc/no-map-spread`	Disallow object and array spreads in the return value of `map` and `flatMap` callbacks	suggestion
`oxc/no-optional-chaining`	Disallow optional chaining (`?.`)
`oxc/no-rest-spread-properties`	Disallow `...` in object literals and object destructuring
`oxc/no-this-in-exported-function`	Disallow `this` in exported functions
`oxc/number-arg-out-of-range`	Disallow out-of-range arguments to `toString`, `toFixed`, `toExponential`, and `toPrecision`
`oxc/only-used-in-recursion`	Disallow parameters that are only passed on to the function's own recursive calls	yes
`oxc/uninvoked-array-callback`	Disallow array methods with a callback directly on `new Array(n)`

Bun

29 rules.

Rule	Description	Fixable
`bun/axios-no-unbounded-requests`	Require an axios request to have a `timeout` or a `signal`
`bun/consistent-directive-prefix`	Require comments that turn rules off to start with the same word, `eslint` or `oxlint`	yes
`bun/fast-check-no-unseeded-random`	Disallow `Math.random()` and `fc.sample()` inside a fast-check property
`bun/format`	Require code to be formatted the way `bun fmt` prints it	yes
`bun/jsx-no-forbidden-nesting`	Disallow a JSX element inside another element that cannot contain it
`bun/no-array-just-to-count`	Disallow `.split(separator).length` with a one-character separator	yes
`bun/no-cast-to-brand`	Disallow casts to a branded type outside the module that declares it
`bun/no-console-window-flash`	Require `windowsHide` for a child process that does not share a stream with its parent
`bun/no-cwd-dependent-path`	Disallow relative paths that depend on the directory the process was started in
`bun/no-eager-dynamic-import`	Disallow `import()` that runs as soon as the module is loaded
`bun/no-eager-native-addon`	Disallow loading a `.node` native addon as soon as the module is loaded
`bun/no-env-at-module-scope`	Disallow reading environment variables as soon as the module is loaded
`bun/no-literal-temp-dir`	Disallow hard-coded temporary directories such as `/tmp` in favor of `os.tmpdir()`
`bun/no-negative-repeat-count`	Disallow a `repeat()` count that comes from a subtraction and can be negative	suggestion
`bun/no-redundant-catch-type`	Disallow `: unknown` on the variable of a `catch` clause	yes
`bun/no-restricted-text`	Disallow text that matches a pattern in strings, templates, JSX text, comments, and regular expressions
`bun/no-side-effects-on-import`	Disallow top-level statements that call something or assign to a property
`bun/no-unhandled-emitter-errors`	Require an `error` listener on event emitters that Node.js functions return
`bun/no-unportable-commands`	Disallow starting a process with a command that does not work the same on every system
`bun/no-useless-spread-fallback`	Disallow an empty object as the fallback in `...(condition ? value : {})`	suggestion
`bun/prefer-builtin-sleep`	Prefer `Bun.sleep()` to a promise that only waits for `setTimeout`	suggestion
`bun/prefer-local-module`	Require importing a package through the module in your project that wraps it	yes
`bun/prefer-timeout-signal`	Prefer `AbortSignal.timeout()` to an `AbortController` that only a timer aborts
`bun/prefer-url-for-sibling-files`	Prefer `new URL("./file", import.meta.url)` to a path joined onto the module's directory
`bun/react-no-latest-value-ref`	Disallow a ref that is set to the latest value on every render
`bun/react-no-local-render-helpers`	Disallow `renderItem()` functions that are defined inside a component and used in its JSX
`bun/react-no-namespace-hooks`	Require React hooks to be imported by name: `useState()`, not `React.useState()`	yes
`bun/react-prefer-updater-function`	Prefer `setItems(previous => ..)` to a new array or object made from the state of the last render
`bun/zod-prefer-lazy-schema`	Disallow building a validation schema while the module loads

bun:test

65 rules.

Rule	Description	Default	Fixable
`bun:test/consistent-test-filename`	Require test files to follow one naming pattern
`bun:test/consistent-test-it`	Enforce one of `test` or `it` for defining tests		yes
`bun:test/expect-expect`	Require every test to make at least one assertion
`bun:test/max-expects`	Enforce a maximum number of `expect()` calls in a test
`bun:test/max-nested-describe`	Enforce a maximum depth of nested `describe()` calls
`bun:test/no-alias-methods`	Disallow matcher aliases such as `toBeCalled` in favor of `toHaveBeenCalled`		yes
`bun:test/no-commented-out-tests`	Disallow tests that are inside a comment
`bun:test/no-conditional-expect`	Disallow `expect` inside `if`, `catch` and other code that only runs sometimes
`bun:test/no-conditional-in-test`	Disallow `if`, `switch`, `? :`, `&&`, `\|\|` and `??` inside a test
`bun:test/no-conditional-tests`	Disallow `test` and `describe` inside an `if` statement
`bun:test/no-disabled-tests`	Disallow skipped tests such as `test.skip`, `xtest` and `xdescribe`	warn
`bun:test/no-done-callback`	Disallow the `done` callback in tests and hooks in favor of promises
`bun:test/no-duplicate-hooks`	Disallow using the same hook twice in one `describe` block
`bun:test/no-export`	Disallow exports from a file that has tests	warn
`bun:test/no-focused-tests`	Disallow `test.only` and `describe.only`	error	suggestion
`bun:test/no-hooks`	Disallow `beforeAll`, `beforeEach`, `afterEach` and `afterAll`
`bun:test/no-identical-title`	Disallow two tests or two `describe` blocks with the same title in one block
`bun:test/no-interpolation-in-snapshots`	Disallow `${}` in inline snapshots
`bun:test/no-large-snapshots`	Disallow snapshots that are longer than a set number of lines
`bun:test/no-restricted-jest-methods`	Disallow the `jest` and `vi` methods that you list
`bun:test/no-restricted-matchers`	Disallow the matchers and modifiers you list
`bun:test/no-standalone-expect`	Disallow `expect` outside of a `test` or `it` block
`bun:test/no-test-prefixes`	Require `.skip` instead of the `x` prefix		yes
`bun:test/no-test-return-statement`	Disallow `return expect(..)` in a test
`bun:test/no-unneeded-async-expect-function`	Disallow an async function around a single awaited call in `expect`		yes
`bun:test/padding-around-after-all-blocks`	Require a blank line before each `afterAll` call		yes
`bun:test/padding-around-test-blocks`	Require a blank line before each `test` and `it` call		yes
`bun:test/prefer-called-once`	Require `toHaveBeenCalledOnce()` instead of `toHaveBeenCalledTimes(1)`		yes
`bun:test/prefer-called-times`	Require `toHaveBeenCalledTimes(1)` instead of `toHaveBeenCalledOnce()`		yes
`bun:test/prefer-called-with`	Require `toHaveBeenCalledWith()` instead of `toHaveBeenCalled()`		suggestion
`bun:test/prefer-comparison-matcher`	Require matchers such as `toBeGreaterThan()` instead of comparing inside `expect()`		suggestion
`bun:test/prefer-describe-function-title`	Require `describe(fn, ...)` instead of a string with the name of an imported function		suggestion
`bun:test/prefer-each`	Require `test.each` and `describe.each` instead of a loop around tests
`bun:test/prefer-ending-with-an-expect`	Require the last statement of a test to be an assertion
`bun:test/prefer-equality-matcher`	Require `toBe` or `toEqual` instead of comparing with `===` inside `expect`		suggestion
`bun:test/prefer-expect-assertions`	Require `expect.assertions()` or `expect.hasAssertions()` at the start of every test		suggestion
`bun:test/prefer-expect-resolves`	Require `await expect(promise).resolves` instead of `expect(await promise)`		suggestion
`bun:test/prefer-expect-type-of`	Require `toBeTypeOf` instead of `expect(typeof value).toBe(...)`		yes
`bun:test/prefer-hooks-in-order`	Require hooks to be written in the order they run
`bun:test/prefer-hooks-on-top`	Require hooks to come before the tests in their block
`bun:test/prefer-lowercase-title`	Require the titles of tests and `describe` blocks to start with a lowercase letter		yes
`bun:test/prefer-mock-promise-shorthand`	Require `mockResolvedValue()` and `mockRejectedValue()` for mocks that return a promise		yes
`bun:test/prefer-mock-return-shorthand`	Require `mockReturnValue()` for a mock that only returns a value		yes
`bun:test/prefer-snapshot-hint`	Require a hint on `toMatchSnapshot()` and `toThrowErrorMatchingSnapshot()`
`bun:test/prefer-spy-on`	Require `spyOn()` instead of assigning `jest.fn()` to a property		suggestion
`bun:test/prefer-strict-boolean-matchers`	Require `toBe(true)` and `toBe(false)` instead of `toBeTruthy()` and `toBeFalsy()`		suggestion
`bun:test/prefer-strict-equal`	Require `toStrictEqual()` instead of `toEqual()`		suggestion
`bun:test/prefer-to-be`	Require `toBe()` for primitive literals, and `toBeNull()`, `toBeUndefined()`, `toBeNaN()`		yes
`bun:test/prefer-to-be-falsy`	Require `toBeFalsy()` instead of `toBe(false)`		suggestion
`bun:test/prefer-to-be-truthy`	Require `toBeTruthy()` instead of `toBe(true)`		suggestion
`bun:test/prefer-to-contain`	Require `toContain()` instead of comparing the result of `includes()` with a boolean		suggestion
`bun:test/prefer-to-have-been-called`	Require `not.toHaveBeenCalled()` instead of `toHaveBeenCalledTimes(0)`		yes
`bun:test/prefer-to-have-been-called-times`	Require `toHaveBeenCalledTimes()` instead of checking the length of `mock.calls`		yes
`bun:test/prefer-to-have-length`	Require `toHaveLength()` instead of comparing the `length` property		yes
`bun:test/prefer-todo`	Require `test.todo` for tests that have no body yet		yes
`bun:test/require-hook`	Require setup and teardown code to be inside a hook
`bun:test/require-mock-type-parameters`	Require a type parameter on `jest.fn()` and `vi.fn()`
`bun:test/require-test-timeout`	Require every test to set a timeout
`bun:test/require-to-throw-message`	Require `toThrow()` to say which error it expects
`bun:test/require-top-level-describe`	Require tests and hooks to be inside a `describe` block
`bun:test/valid-describe-callback`	Require `describe` to get a callback that is a function with no parameters	error
`bun:test/valid-expect`	Require `expect` to get a value, end in a called matcher, and be awaited when it is async	error	suggestion
`bun:test/valid-expect-in-promise`	Require a promise chain that contains `expect` to be awaited or returned from the test	error
`bun:test/valid-title`	Require test and `describe` titles to be non-empty, with no stray spaces or repeated prefix		yes
`bun:test/warn-todo`	Disallow `.todo` on `test`, `it` and `describe`

Jest

60 rules.

Rule	Description	Fixable
`jest/consistent-test-it`	Enforce one of `test` or `it` for defining tests	yes
`jest/expect-expect`	Require every test to make at least one assertion
`jest/max-expects`	Enforce a maximum number of `expect()` calls in a test
`jest/max-nested-describe`	Enforce a maximum depth of nested `describe()` calls
`jest/no-alias-methods`	Disallow matcher aliases such as `toBeCalled` in favor of `toHaveBeenCalled`	yes
`jest/no-commented-out-tests`	Disallow tests that are inside a comment
`jest/no-conditional-expect`	Disallow `expect` inside `if`, `catch` and other code that only runs sometimes
`jest/no-conditional-in-test`	Disallow `if`, `switch`, `? :`, `&&`, `\|\|` and `??` inside a test
`jest/no-confusing-set-timeout`	Disallow `jest.setTimeout` inside a block, after a test, or more than once in a file
`jest/no-deprecated-functions`	Disallow Jest functions that have been renamed or replaced	yes
`jest/no-disabled-tests`	Disallow skipped tests such as `test.skip`, `xtest` and `xdescribe`
`jest/no-done-callback`	Disallow the `done` callback in tests and hooks in favor of promises
`jest/no-duplicate-hooks`	Disallow using the same hook twice in one `describe` block
`jest/no-export`	Disallow exports from a file that has tests
`jest/no-focused-tests`	Disallow `test.only`, `describe.only`, `fit` and `fdescribe`	suggestion
`jest/no-hooks`	Disallow `beforeAll`, `beforeEach`, `afterEach` and `afterAll`
`jest/no-identical-title`	Disallow two tests or two `describe` blocks with the same title in one block
`jest/no-interpolation-in-snapshots`	Disallow `${}` in inline snapshots
`jest/no-jasmine-globals`	Disallow Jasmine globals such as `jasmine.any`, `spyOn`, `fail` and `pending`	yes
`jest/no-large-snapshots`	Disallow snapshots that are longer than a set number of lines
`jest/no-mocks-import`	Disallow importing from a `__mocks__` directory
`jest/no-restricted-jest-methods`	Disallow the `jest` methods that you list
`jest/no-restricted-matchers`	Disallow the matchers and modifiers you list
`jest/no-standalone-expect`	Disallow `expect` outside of a `test` or `it` block
`jest/no-test-prefixes`	Require `.only` and `.skip` instead of the `f` and `x` prefixes	yes
`jest/no-test-return-statement`	Disallow `return expect(..)` in a test
`jest/no-unneeded-async-expect-function`	Disallow an async function around a single awaited call in `expect`	yes
`jest/no-untyped-mock-factory`	Require a type parameter on `jest.mock()` and `jest.doMock()` with a factory	yes
`jest/padding-around-after-all-blocks`	Require a blank line before each `afterAll` call	yes
`jest/padding-around-test-blocks`	Require a blank line before each `test` and `it` call	yes
`jest/prefer-called-with`	Require `toHaveBeenCalledWith()` instead of `toHaveBeenCalled()`	yes
`jest/prefer-comparison-matcher`	Require matchers such as `toBeGreaterThan()` instead of comparing inside `expect()`	yes
`jest/prefer-each`	Require `test.each` and `describe.each` instead of a loop around tests
`jest/prefer-ending-with-an-expect`	Require the last statement of a test to be an assertion
`jest/prefer-equality-matcher`	Require `toBe` or `toEqual` instead of comparing with `===` inside `expect`	suggestion
`jest/prefer-expect-assertions`	Require `expect.assertions()` or `expect.hasAssertions()` at the start of every test	suggestion
`jest/prefer-expect-resolves`	Require `await expect(promise).resolves` instead of `expect(await promise)`	yes
`jest/prefer-hooks-in-order`	Require hooks to be written in the order they run
`jest/prefer-hooks-on-top`	Require hooks to come before the tests in their block
`jest/prefer-importing-jest-globals`	Require `describe`, `test`, `expect` and `jest` to be imported from `@jest/globals`	yes
`jest/prefer-jest-mocked`	Require `jest.mocked(fn)` instead of `fn as jest.Mock`	yes
`jest/prefer-lowercase-title`	Require the titles of tests and `describe` blocks to start with a lowercase letter	yes
`jest/prefer-mock-promise-shorthand`	Require `mockResolvedValue()` and `mockRejectedValue()` for mocks that return a promise	yes
`jest/prefer-mock-return-shorthand`	Require `mockReturnValue()` for a mock that only returns a value	yes
`jest/prefer-snapshot-hint`	Require a hint on `toMatchSnapshot()` and `toThrowErrorMatchingSnapshot()`
`jest/prefer-spy-on`	Require `jest.spyOn()` instead of assigning `jest.fn()` to a property	suggestion
`jest/prefer-strict-equal`	Require `toStrictEqual()` instead of `toEqual()`	suggestion
`jest/prefer-to-be`	Require `toBe()` for primitive literals, and `toBeNull()`, `toBeUndefined()`, `toBeNaN()`	yes
`jest/prefer-to-contain`	Require `toContain()` instead of comparing the result of `includes()` with a boolean	yes
`jest/prefer-to-have-been-called`	Require `not.toHaveBeenCalled()` instead of `toHaveBeenCalledTimes(0)`	yes
`jest/prefer-to-have-been-called-times`	Require `toHaveBeenCalledTimes()` instead of checking the length of `mock.calls`	yes
`jest/prefer-to-have-length`	Require `toHaveLength()` instead of comparing the `length` property	yes
`jest/prefer-todo`	Require `test.todo` for tests that have no body yet	yes
`jest/require-hook`	Require setup and teardown code to be inside a hook
`jest/require-to-throw-message`	Require `toThrow()` to say which error it expects
`jest/require-top-level-describe`	Require tests and hooks to be inside a `describe` block
`jest/valid-describe-callback`	Require `describe` to get a title and a plain synchronous callback
`jest/valid-expect`	Require `expect` to get a value, end in a called matcher, and be awaited when it is async	suggestion
`jest/valid-expect-in-promise`	Require a promise chain that contains `expect` to be awaited or returned from the test
`jest/valid-title`	Require test and `describe` titles to be non-empty strings with no stray spaces or repeated prefix	yes

Vitest

73 rules.

Rule	Description	Fixable
`vitest/consistent-each-for`	Enforce either `.each` or `.for` for parameterized tests
`vitest/consistent-test-filename`	Require test files to follow one naming pattern
`vitest/consistent-test-it`	Enforce one of `test` or `it` for defining tests	yes
`vitest/consistent-vitest-vi`	Enforce one of `vi` or `vitest` for Vitest's helper object	yes
`vitest/expect-expect`	Require every test to make at least one assertion
`vitest/hoisted-apis-on-top`	Require `vi.mock`, `vi.unmock` and `vi.hoisted` at the top level of the file	suggestion
`vitest/max-expects`	Enforce a maximum number of `expect()` calls in a test
`vitest/max-nested-describe`	Enforce a maximum depth of nested `describe()` calls
`vitest/no-alias-methods`	Disallow matcher aliases such as `toBeCalled` in favor of `toHaveBeenCalled`	yes
`vitest/no-commented-out-tests`	Disallow tests that are inside a comment
`vitest/no-conditional-expect`	Disallow `expect` inside `if`, `catch` and other code that only runs sometimes
`vitest/no-conditional-in-test`	Disallow `if`, `switch`, `? :`, `&&`, `\|\|` and `??` inside a test
`vitest/no-conditional-tests`	Disallow `test` and `describe` inside an `if` statement
`vitest/no-disabled-tests`	Disallow skipped tests such as `test.skip` and `describe.skip`
`vitest/no-duplicate-hooks`	Disallow using the same hook twice in one `describe` block
`vitest/no-focused-tests`	Disallow `test.only` and `describe.only`	suggestion
`vitest/no-hooks`	Disallow `beforeAll`, `beforeEach`, `afterEach` and `afterAll`
`vitest/no-identical-title`	Disallow two tests or two `describe` blocks with the same title in one block
`vitest/no-import-node-test`	Disallow importing from `node:test` in a project that uses Vitest	suggestion
`vitest/no-importing-vitest-globals`	Disallow importing `test`, `expect`, `vi` and the other Vitest globals	yes
`vitest/no-interpolation-in-snapshots`	Disallow `${}` in inline snapshots
`vitest/no-large-snapshots`	Disallow snapshots that are longer than a set number of lines
`vitest/no-mocks-import`	Disallow importing from a `__mocks__` directory
`vitest/no-restricted-matchers`	Disallow the matchers and modifiers you list
`vitest/no-restricted-vi-methods`	Disallow the `vi` methods you list
`vitest/no-standalone-expect`	Disallow `expect` outside of a `test` or `it` block
`vitest/no-test-prefixes`	Require `.only` and `.skip` instead of the `f` and `x` prefixes	yes
`vitest/no-test-return-statement`	Disallow `return expect(..)` in a test
`vitest/no-unneeded-async-expect-function`	Disallow an async function around a single awaited call in `expect`	yes
`vitest/padding-around-after-all-blocks`	Require a blank line before each `afterAll` call	yes
`vitest/padding-around-test-blocks`	Require a blank line before each `test` and `it` call	yes
`vitest/prefer-called-exactly-once-with`	Require `toHaveBeenCalledExactlyOnceWith()` over separate call count and argument checks	yes
`vitest/prefer-called-once`	Require `toHaveBeenCalledOnce()` instead of `toHaveBeenCalledTimes(1)`	yes
`vitest/prefer-called-times`	Require `toHaveBeenCalledTimes(1)` instead of `toHaveBeenCalledOnce()`	yes
`vitest/prefer-called-with`	Require `toHaveBeenCalledWith()` instead of `toHaveBeenCalled()`	yes
`vitest/prefer-comparison-matcher`	Require matchers such as `toBeGreaterThan()` instead of comparing inside `expect()`	yes
`vitest/prefer-describe-function-title`	Require `describe(fn, ...)` instead of a string with the name of an imported function	yes
`vitest/prefer-each`	Require `test.each` and `describe.each` instead of a loop around tests
`vitest/prefer-equality-matcher`	Require `toBe` or `toEqual` instead of comparing with `===` inside `expect`	suggestion
`vitest/prefer-expect-assertions`	Require `expect.assertions()` or `expect.hasAssertions()` at the start of every test	suggestion
`vitest/prefer-expect-resolves`	Require `await expect(promise).resolves` instead of `expect(await promise)`	yes
`vitest/prefer-expect-type-of`	Require `toBeTypeOf` instead of `expect(typeof value).toBe(...)`	yes
`vitest/prefer-hooks-in-order`	Require hooks to be written in the order they run
`vitest/prefer-hooks-on-top`	Require hooks to come before the tests in their block
`vitest/prefer-import-in-mock`	Require `import()` instead of a string path in `vi.mock()` and `vi.doMock()`	yes
`vitest/prefer-importing-vitest-globals`	Require `describe`, `test`, `expect` and `vi` to be imported from `vitest`	yes
`vitest/prefer-lowercase-title`	Require the titles of tests and `describe` blocks to start with a lowercase letter	yes
`vitest/prefer-mock-promise-shorthand`	Require `mockResolvedValue()` and `mockRejectedValue()` for mocks that return a promise	yes
`vitest/prefer-mock-return-shorthand`	Require `mockReturnValue()` for a mock that only returns a value	yes
`vitest/prefer-snapshot-hint`	Require a hint on `toMatchSnapshot()` and `toThrowErrorMatchingSnapshot()`
`vitest/prefer-spy-on`	Require `vi.spyOn()` instead of assigning `vi.fn()` to a property	suggestion
`vitest/prefer-strict-boolean-matchers`	Require `toBe(true)` and `toBe(false)` instead of `toBeTruthy()` and `toBeFalsy()`	yes
`vitest/prefer-strict-equal`	Require `toStrictEqual()` instead of `toEqual()`	suggestion
`vitest/prefer-to-be`	Require `toBe()` for primitive literals, and `toBeNull()`, `toBeUndefined()`, `toBeNaN()`	yes
`vitest/prefer-to-be-falsy`	Require `toBeFalsy()` instead of `toBe(false)`	suggestion
`vitest/prefer-to-be-object`	Require `toBeObject()` when `expectTypeOf()` checks for an object	yes
`vitest/prefer-to-be-truthy`	Require `toBeTruthy()` instead of `toBe(true)`	suggestion
`vitest/prefer-to-contain`	Require `toContain()` instead of comparing the result of `includes()` with a boolean	yes
`vitest/prefer-to-have-been-called-times`	Require `toHaveBeenCalledTimes()` instead of checking the length of `mock.calls`	yes
`vitest/prefer-to-have-length`	Require `toHaveLength()` instead of comparing the `length` property	yes
`vitest/prefer-todo`	Require `test.todo` for tests that have no body yet	yes
`vitest/require-awaited-expect-poll`	Require `expect.poll` and `expect.element` assertions to be awaited or returned
`vitest/require-hook`	Require setup and teardown code to be inside a hook
`vitest/require-local-test-context-for-concurrent-snapshots`	Require the `expect` of the test context for snapshots in concurrent tests
`vitest/require-mock-type-parameters`	Require a type parameter on `vi.fn()`
`vitest/require-test-timeout`	Require every test to set a timeout
`vitest/require-to-throw-message`	Require `toThrow()` to say which error it expects
`vitest/require-top-level-describe`	Require tests and hooks to be inside a `describe` block
`vitest/valid-describe-callback`	Require `describe` to get a title and a callback with no parameters and no `return`
`vitest/valid-expect`	Require `expect` to get a value, end in a called matcher, and be awaited when it is async	suggestion
`vitest/valid-expect-in-promise`	Require a promise chain that contains `expect` to be awaited or returned from the test
`vitest/valid-title`	Require test and `describe` titles to be non-empty strings with no stray spaces or repeated prefix	yes
`vitest/warn-todo`	Disallow `.todo` on `test`, `it` and `describe`

Prettier

1 rules.

Rule	Description	Default	Fixable	Needs types
`prettier/prettier`	Require code to be formatted the way Prettier prints it		yes