@webpack-contrib/eslint-config-webpack/rules/best-practices.js

module.exports = {
  rules: {
    // enforce getter and setter pairs in objects
    // http://eslint.org/docs/rules/accessor-pairs
    'accessor-pairs': 'off',

    // enforce return statements in callbacks of array methods
    // http://eslint.org/docs/rules/array-callback-return
    'array-callback-return': 'error',

    // enforce the use of variables within the scope they are defined
    // http://eslint.org/docs/rules/block-scoped-var
    'block-scoped-var': 'error',

    // enforce that class methods utilize this
    // http://eslint.org/docs/rules/class-methods-use-this
    'class-methods-use-this': ['error', {
      exceptMethods: [],
    }],

    // enforce a maximum cyclomatic complexity allowed in a program
    // http://eslint.org/docs/rules/complexity
    complexity: ['off', 11],

    // require return statements to either always or never specify values
    // http://eslint.org/docs/rules/consistent-return
    'consistent-return': 'error',

    // enforce consistent brace style for all control statements
    // http://eslint.org/docs/rules/curly
    // This is handled by Prettier in Defaults 2.0
    curly: 'off',

    // require default cases in switch statements
    // http://eslint.org/docs/rules/default-case
    'default-case': ['error', { commentPattern: '^no default$' }],

    // enforce consistent newlines before and after dots
    // http://eslint.org/docs/rules/dot-location
    // This is handled by Prettier in Defaults 2.0
    'dot-location': 'off',

    // enforce dot notation whenever possible
    // http://eslint.org/docs/rules/dot-notation
    'dot-notation': ['error', { allowKeywords: true }],

    // require the use of === and !==
    // http://eslint.org/docs/rules/eqeqeq
    eqeqeq: ['error', 'always', { null: 'ignore' }],

    // require for-in loops to include an if statement
    // http://eslint.org/docs/rules/guard-for-in
    'guard-for-in': 'error',

    // disallow the use of alert, confirm, and prompt
    // http://eslint.org/docs/rules/no-alert
    'no-alert': 'warn',

    // disallow the use of arguments.caller or arguments.callee
    // http://eslint.org/docs/rules/no-caller
    'no-caller': 'error',

    // disallow lexical declarations in case clauses
    // http://eslint.org/docs/rules/no-case-declarations.html
    'no-case-declarations': 'error',

    // disallow division operators explicitly at the beginning of regular expressions
    // http://eslint.org/docs/rules/no-div-regex
    'no-div-regex': 'off',

    // disallow else blocks after return statements in if statements
    // http://eslint.org/docs/rules/no-else-return
    'no-else-return': 'error',

    // disallow empty functions
    // http://eslint.org/docs/rules/no-empty-function
    'no-empty-function': ['error', {
      allow: [
        'arrowFunctions',
        'functions',
        'methods',
      ],
    }],

    // disallow empty destructuring patterns
    // http://eslint.org/docs/rules/no-empty-pattern
    'no-empty-pattern': 'error',

    // disallow null comparisons without type-checking operators
    // http://eslint.org/docs/rules/no-eq-null
    'no-eq-null': 'off',

    // disallow the use of eval()
    // http://eslint.org/docs/rules/no-eval
    'no-eval': 'error',

    // disallow extending native types
    // http://eslint.org/docs/rules/no-extend-native
    'no-extend-native': 'error',

    // disallow unnecessary calls to .bind()
    // http://eslint.org/docs/rules/no-extra-bind
    'no-extra-bind': 'error',

    // disallow unnecessary labels
    // http://eslint.org/docs/rules/no-extra-label
    'no-extra-label': 'error',

    // disallow fallthrough of case statements
    // http://eslint.org/docs/rules/no-fallthrough
    'no-fallthrough': 'error',

    // disallow leading or trailing decimal points in numeric literals
    // http://eslint.org/docs/rules/no-floating-decimal
    // This is handled by Prettier in Defaults 2.0
    'no-floating-decimal': 'off',

    // disallow assignments to native objects or read-only global variables
    // http://eslint.org/docs/rules/no-global-assign
    'no-global-assign': ['error', { exceptions: [] }],

    // disallow shorthand type conversions
    // http://eslint.org/docs/rules/no-implicit-coercion
    'no-implicit-coercion': ['off', {
      boolean: false,
      number: true,
      string: true,
      allow: [],
    }],

    // disallow variable and function declarations in the global scope
    // http://eslint.org/docs/rules/no-implicit-globals
    'no-implicit-globals': 'off',

    // disallow the use of eval()-like methods
    // http://eslint.org/docs/rules/no-implied-eval
    'no-implied-eval': 'error',

    // disallow this keywords outside of classes or class-like objects
    // http://eslint.org/docs/rules/no-invalid-this
    'no-invalid-this': 'off',

    // disallow the use of the __iterator__ property
    // http://eslint.org/docs/rules/no-iterator
    'no-iterator': 'error',

    // disallow labeled statements
    // http://eslint.org/docs/rules/no-labels
    'no-labels': ['error', { allowLoop: false, allowSwitch: false }],

    // disallow unnecessary nested blocks
    // http://eslint.org/docs/rules/no-lone-blocks
    'no-lone-blocks': 'error',

    // disallow function declarations and expressions inside loop statements
    // http://eslint.org/docs/rules/no-loop-func
    'no-loop-func': 'error',

    // disallow magic numbers
    // http://eslint.org/docs/rules/no-magic-numbers
    'no-magic-numbers': ['off', {
      ignore: [],
      ignoreArrayIndexes: true,
      enforceConst: true,
      detectObjects: false,
    }],

    // disallow multiple spaces
    // http://eslint.org/docs/rules/no-multi-spaces
    // This is handled by Prettier in Defaults 2.0
    'no-multi-spaces': 'off',

    // disallow multiline strings
    // http://eslint.org/docs/rules/no-multi-str
    'no-multi-str': 'error',

    // disallow new operators with the Function object
    // http://eslint.org/docs/rules/no-new-func
    'no-new-func': 'error',

    // disallow new operators with the String, Number, and Boolean objects
    // http://eslint.org/docs/rules/no-new-wrappers
    'no-new-wrappers': 'error',

    // disallow new operators outside of assignments or comparisons
    // http://eslint.org/docs/rules/no-new
    'no-new': 'error',

    // disallow octal escape sequences in string literals
    // http://eslint.org/docs/rules/no-octal-escape
    'no-octal-escape': 'error',

    // disallow octal literals
    // http://eslint.org/docs/rules/no-octal
    'no-octal': 'error',

    // disallow reassigning function parameters
    // rule: http://eslint.org/docs/rules/no-param-reassign.html
    'no-param-reassign': ['warn', { props: true }],

    // disallow the use of the __proto__ property
    // http://eslint.org/docs/rules/no-proto
    'no-proto': 'error',

    // disallow variable redeclaration
    // http://eslint.org/docs/rules/no-redeclare
    'no-redeclare': 'error',

    // disallow certain properties on certain objects
    // http://eslint.org/docs/rules/no-restricted-properties
    'no-restricted-properties': ['error', {
      object: 'arguments',
      property: 'callee',
      message: 'arguments.callee is deprecated',
    }, {
      property: '__defineGetter__',
      message: 'Please use Object.defineProperty instead.',
    }, {
      property: '__defineSetter__',
      message: 'Please use Object.defineProperty instead.',
    }, {
      object: 'Math',
      property: 'pow',
      message: 'Use the exponentiation operator (**) instead.',
    }],

    // disallow assignment operators in return statements
    // http://eslint.org/docs/rules/no-return-assign
    'no-return-assign': 'error',

    // disallow unnecessary return await
    // http://eslint.org/docs/rules/no-return-await
    'no-return-await': 'error',

    // disallow javascript: urls
    // http://eslint.org/docs/rules/no-script-url
    'no-script-url': 'error',

    // disallow assignments where both sides are exactly the same
    // http://eslint.org/docs/rules/no-self-assign
    'no-self-assign': 'error',

    // disallow comparisons where both sides are exactly the same
    // http://eslint.org/docs/rules/no-self-compare
    'no-self-compare': 'error',

    // disallow comma operators
    // http://eslint.org/docs/rules/no-sequences
    'no-sequences': 'error',

    // disallow throwing literals as exceptions
    // http://eslint.org/docs/rules/no-throw-literal
    'no-throw-literal': 'error',

    // disallow unmodified loop conditions
    // http://eslint.org/docs/rules/no-unmodified-loop-condition
    'no-unmodified-loop-condition': 'off',

    // disallow unused expressions
    // http://eslint.org/docs/rules/no-unused-expressions
    'no-unused-expressions': ['error', {
      allowShortCircuit: false,
      allowTernary: false,
    }],

    // disallow unused labels
    // http://eslint.org/docs/rules/no-unused-labels
    'no-unused-labels': 'error',

    // disallow unnecessary calls to .call() and .apply()
    // http://eslint.org/docs/rules/no-useless-call
    'no-useless-call': 'off',

    // disallow unnecessary concatenation of literals or template literals
    // http://eslint.org/docs/rules/no-useless-concat
    'no-useless-concat': 'error',

    // disallow unnecessary escape characters
    // http://eslint.org/docs/rules/no-useless-escape
    'no-useless-escape': 'error',

    // disallow redundant return statements
    // http://eslint.org/docs/rules/no-useless-return
    'no-useless-return': 'error',

    // disallow void operators
    // http://eslint.org/docs/rules/no-void
    'no-void': 'error',

    // disallow specified warning terms in comments
    // http://eslint.org/docs/rules/no-warning-comments
    'no-warning-comments': ['off', { terms: ['todo', 'fixme', 'xxx'], location: 'start' }],

    // disallow with statements
    // http://eslint.org/docs/rules/no-with
    'no-with': 'error',

    // require using Error objects as Promise rejection reasons
    // http://eslint.org/docs/rules/prefer-promise-reject-errors
    'prefer-promise-reject-errors': ['error', { allowEmptyReject: true }],

    // enforce the consistent use of the radix argument when using parseInt()
    // http://eslint.org/docs/rules/radix
    radix: 'error',

    // disallow async functions which have no await expression
    // http://eslint.org/docs/rules/require-await
    'require-await': 'off',

    // require var declarations be placed at the top of their containing scope
    // http://eslint.org/docs/rules/vars-on-top
    'vars-on-top': 'error',

    // require parentheses around immediate function invocations
    // http://eslint.org/docs/rules/wrap-iife.html
    // This is handled by Prettier in Defaults 2.0
    'wrap-iife': 'off',

    // require or disallow “Yoda” conditions
    // http://eslint.org/docs/rules/yoda
    yoda: 'error',
  },
};