Possible Errors

Best Practices

Strict Mode

Variables

Node.js and CommonJS

Stylistic Issues

ECMAScript 6

arrow-body-style

Require braces around arrow function bodies

arrow-parens

Require parentheses around arrow function arguments

arrow-spacing

Enforce consistent spacing before and after the arrow in arrow functions

constructor-super

Require super() calls in constructors

generator-star-spacing

Enforce consistent spacing around * operators in generator functions

no-class-assign

Disallow reassigning class members

no-confusing-arrow

Disallow arrow functions where they could be confused with comparisons

no-const-assign

Disallow reassigning const variables

no-dupe-class-members

Disallow duplicate class members

no-duplicate-imports

Disallow duplicate module imports

no-new-symbol

Disallow new operators with the Symbol object

no-restricted-imports

Disallow specified modules when loaded by import

no-this-before-super

Disallow this/super before calling super() in constructors

no-useless-computed-key

Disallow unnecessary computed property keys in object literals

no-useless-constructor

Disallow unnecessary constructors

no-useless-rename

Disallow renaming import, export, and destructured assignments to the same name

no-var

Require let or const instead of var

object-shorthand

Require or disallow method and property shorthand syntax for object literals

prefer-arrow-callback

Require using arrow functions for callbacks

prefer-const

Require const declarations for variables that are never reassigned after declared

prefer-destructuring

Require destructuring from arrays and/or objects

prefer-numeric-literals

Disallow parseInt() and Number.parseInt() in favor of binary, octal, and hexadecimal literals

prefer-rest-params

Require rest parameters instead of arguments

prefer-spread

Require spread operators instead of .apply()

prefer-template

Require template literals instead of string concatenation

require-yield

Require generator functions to contain yield

rest-spread-spacing

Enforce spacing between rest and spread operators and their expressions

sort-imports

Enforce sorted import declarations within modules

symbol-description

Require symbol descriptions

template-curly-spacing

Require or disallow spacing around embedded expressions of template strings

yield-star-spacing

Require or disallow spacing around the * in yield* expressions

Download Preview

no-useless-constructor

- Disallow unnecessary constructors

This rule flags class constructors that can be safely removed without changing how the class works.

What ESLint should do when it catches the rule break

Show a warning

Rule examples

You can check them out here.

no-useless-computed-key no-useless-rename