API v5.1.x


npm: npm install @hapi/eslint-plugin

yarn: yarn add @hapi/eslint-plugin


This ESLint plugin exposes two configurations:

  • @hapi/recommended
  • @hapi/module


An ESLint configuration containing hapi style guide rules and config. To use in your project, add @hapi/eslint-plugin to your package.json, then in your ESLint configuration add:

  "extends": "plugin:@hapi/recommended"


The ESLint configuration used by @hapi/lab when you use the linting feature through either the -L command argument or the lint: true configuration.

To use it in your project, there are multiple dependencies you need to add to your package.json:

Then in your ESLint configuration add:

  "extends": "plugin:@hapi/module"


This plugin includes the following ESLint rules:


Enforces capitalization of imported module variables.


If the string 'global-scope-only' is passed as the first option to this rule, then it will only be enforced on assignments in the module's top level scope.


Enforces for loop iterator variable rules and restricts loop nesting depth.

This rule enforces the following:

  • Restrict iterator variable names. for loop iterator variables should be named i. Nested loops should use the variables j, k, and so on.
  • Restrict loop nesting. You can restrict the maximum nesting of for loops. By default, this limit is three.
  • Prevent postfix increment and decrement operators. The hapi style guide does not allow postfix increment and decrement operators in for loop updates. The prefix version of these operators should be used instead.
  • Single variable declaration in initialization section. A single var i = 0; is allowed in the initialization section. This only applies to variable declarations, not assignments to existing variables. This means that for (i = 0, j = 0) is allowed if i and j are existing variables. Variable declarations involving destructuring are not allowed.

Rule options

This rule can be configured by providing a single options object. The object supports the following keys.


A number representing the maximum allowed nesting of for loops. Defaults to three.


The first variable iterator name to use. This defaults to 'i'.


Enforces the usage of var declarations only in try-catch scope.


Enforces a new line at the beginning of function scope.


If the string 'allow-one-liners' is passed as the first option to this rule, then functions whose bodies contain zero or one statements are allowed to be written on a single line. This defaults to true for arrow functions, and false otherwise.


The second option to this rule dictates the maximum number of statements allowed in the bodies of one line function. This must be used in conjunction with allow-one-liners. Defaults to one.


Prevents arrow functions that implicitly create additional arrow functions.

This rule prevents the pattern () => () => () => ...;.

Functions can still be returned by arrow functions whose bodies use curly braces and an explicit return.

This rule does not accept any configuration options.


Rule Option
'@hapi/capitalize-modules' ['warn', 'global-scope-only']
'@hapi/for-loop' ['warn', { maxDepth: 3, startIterator: 'i' }]
'@hapi/no-var' 'error'
'@hapi/scope-start' 'warn'
'@hapi/no-arrowception' 'error'
'camelcase' 'off'
'consistent-return' 'off'
'vars-on-top' 'off'
'new-cap' 'off
'no-console' 'off'
'no-constant-condition' 'error'
'no-empty' 'off'
'no-native-reassign' 'off'
'no-underscore-dangle' 'off'
'no-undef' ['error', { typeof: false }]
'no-process-exit' 'off'
'no-unused-expressions' 'off'
'no-regex-spaces' 'off'
'no-catch-shadow' 'off'
'no-lonely-if' 'off'
'brace-style' ['warn', 'stroustrup']
'no-shadow' ['warn', { allow: ['err', 'done'] }]
'no-unused-vars' ['warn', { vars: 'all', varsIgnorePattern: '^internals$', args: 'none' }]
'one-var' ['error', 'never']
'handle-callback-err' ['error', '^(e|err|error)$']
'array-bracket-spacing' 'warn'
'dot-notation' 'warn'
'eol-last' 'warn'
'no-trailing-spaces' 'warn'
'no-eq-null' 'warn'
'no-extend-native' 'warn'
'no-redeclare' 'warn'
'no-loop-func' 'warn'
'yoda' ['warn', 'never']
'sort-vars' 'warn'
'arrow-parens' ['error', 'always']
'arrow-spacing' ['error', { before: true, after: true }]
'quotes' ['error', 'single', { allowTemplateLiterals: true }]
'consistent-this' ['error', 'self']
'new-parens' 'error'
'no-array-constructor' 'error'
'no-confusing-arrow' 'error'
'no-new-object' 'error'
'no-spaced-func' 'error'
'no-mixed-spaces-and-tabs' 'error'
'key-spacing' 'error'
'keyword-spacing' ['error', { before: true, after: true }]
'semi' ['error', 'always']
'semi-spacing' ['error', { before: false, after: true }]
'space-before-blocks' 'error'
'space-infix-ops' 'error'
'space-unary-ops' ['warn', { words: true, nonwords: false }]
'strict' ['error', 'global']
'eqeqeq' 'error'
'curly' ['error', 'all']
'no-eval' 'error'
'no-else-return' 'error'
'no-return-assign' 'error'
'no-new-wrappers' 'error'
'comma-dangle' ['error', 'never']
'no-sparse-arrays' 'error'
'no-ex-assign' 'error'
'prefer-arrow-callback' 'error'
'prefer-const' ['error', { destructuring: 'all' }]
'indent' ['error', 4, { SwitchCase: 1 }]
'space-before-function-paren' ['error', { anonymous: 'always', named: 'never' }]
'func-style' ['error', 'expression']
'object-curly-spacing' ['error', 'always']
'object-shorthand' ['error', 'properties']
'no-unsafe-finally' 'error'
'no-useless-computed-key' 'error'
'require-await' 'error'
'constructor-super' 'error'
'no-buffer-constructor' 'error'
'no-mixed-requires' 'error'
'no-new-require' 'error'
'no-caller' 'error'
'no-const-assign' 'error'
'no-dupe-class-members' 'error'
'no-class-assign' 'warn'
'no-new-symbol' 'error
'no-this-before-super' 'error'
'prefer-rest-params' 'error'
'prefer-spread' 'error'
'no-useless-call' 'error'
'rest-spread-spacing' ['error', 'never']
'no-extra-semi' 'error'
'no-dupe-keys' 'error'
'padding-line-between-statements' [
{ blankLine: 'always', prev: 'directive', next: '*' },
{ blankLine: 'any', prev: 'directive', next: 'directive' },
{ blankLine: 'always', prev: 'cjs-import', next: '*' },
{ blankLine: 'any', prev: 'cjs-import', next: 'cjs-import' },
{ blankLine: 'always', prev: 'cjs-export', next: '*' },
{ blankLine: 'always', prev: 'multiline-block-like', next: '*' },
{ blankLine: 'always', prev: 'class', next: '*' }