.eslintrc.yml

parser: esprima
parserOptions:
  sourceType: module
  ecmaFeatures:
    classes: true
    modules: true
    blockBindings: true
    forOf: true

plugins:
  - unicorn
  - mocha-no-only
  - import

env:
  node: true
  es6: true
  mocha: true

rules:
  # [Possible errors]
  comma-dangle:
    - error
    - always-multiline
  no-cond-assign: error
  no-constant-condition: error
  no-dupe-args: error
  no-dupe-keys: error
  no-duplicate-case: error
  no-empty: warn
  no-extra-boolean-cast: error
  no-extra-semi: error
  no-func-assign: error
  no-inner-declarations: error
  no-invalid-regexp: error
  no-irregular-whitespace: error
  no-negated-in-lhs: error
  no-obj-calls: error
  no-sparse-arrays: error
  use-isnan: error
  valid-typeof: error
  no-unexpected-multiline: error
  no-unreachable: warn

  # [Best practices]
  no-lone-blocks: warn
  no-multi-spaces: error
  no-native-reassign: error
  no-new: warn
  no-redeclare: error
  no-self-compare: error
  no-sequences: error
  no-unused-expressions: error
  no-with: error
  wrap-iife: error
  dot-notation:
    - error
    - allowKeywords: true
  no-eval: error
  no-alert: warn
  eqeqeq:
    - error
    - allow-null
  curly:
    - error
    - all

  # [Variables]
  no-shadow-restricted-names: error
  no-shadow: error
  no-undef-init: error
  no-undef: error
  no-undefined: warn
  no-unused-vars: warn
  no-use-before-define: error

  # Stylistic issues
  array-bracket-spacing:
    - error
    - never
  # block-spacing:
  #  - error
  #  - always
  brace-style:
    - error
    - 1tbs
    - allowSingleLine: true
  # camelcase:
  #   - warn
  #   - properties: never
  comma-spacing:
    - error
    - before: false
      after: true
  comma-style:
    - error
    - last
  computed-property-spacing:
    - error
    - never
  eol-last: error
  # func-style:
  #  - error
  #  - declaration
  # indent:
  #   - warn
  #   - 2
  #   - MemberExpression: 0
  #     flatTernaryExpressions: true
  #     ignoredNodes:
  #       - ConditionalExpression
  key-spacing:
    - error
    - beforeColon: false
      afterColon: true
  # linebreak-style:
  #   - error
  #   - unix
  new-cap:
    - error
    - capIsNew: false
  new-parens: error
  no-mixed-spaces-and-tabs: error
  no-new-object: error
  no-spaced-func: error
  no-trailing-spaces: error
  no-unneeded-ternary: error
  object-curly-spacing:
    - error
    - always
  one-var:
    - error
    - never
  operator-assignment:
    - warn
    - always
  operator-linebreak:
    - error
    - before
  # padded-blocks:
  #   - warn
  #   - never
  quotes:
    - warn
    - single
  quote-props:
    - error
    - as-needed
    - keywords: true
  semi: error
  semi-spacing:
    - error
    - before: false
      after: true
  space-before-blocks:
    - error
    - always
  keyword-spacing: error
  space-before-function-paren:
    - error
    - never
  space-in-parens:
    - error
    - never
  space-infix-ops: error
  space-unary-ops: error

  # [ES6]
  arrow-parens:
    - error
    - always
  arrow-spacing:
    - error
    - before: true
      after: true
  constructor-super: error
  no-class-assign: error
  no-const-assign: error
  no-dupe-class-members: error
  no-this-before-super: warn
  no-var: error
  # object-shorthand: error
  # prefer-arrow-callback: error
  # prefer-const: warn
  prefer-spread: warn
  # prefer-template: error
  unicorn/no-abusive-eslint-disable: error

  # [mocha]
  mocha-no-only/mocha-no-only: error