.eslintrc.yml

---
parser: babel-eslint
extends: eslint:recommended
plugins:
  - react
  - react-native
env:
  react-native/react-native: true
parserOptions:
  ecmaFeatures:
    jsx: true
rules:
  # ESLint
  no-var: error                            # disallow use of var for variables
  camelcase: error                         # require camelCase for naming
  key-spacing: error                       # require consistent spacing between key-value pairs
  comma-dangle: error                      # disallow lonely commas in last line
  block-spacing: error                     # require spacing in between curly braces for blocks
  spaced-comment: error                    # require space after comments
  space-in-parens: error                   # disallow spaces around parenthesis
  no-multi-spaces: error                   # disallow whitespace around expressions and declarations
  space-infix-ops: error                   # require spaces around operators
  func-call-spacing: error                 # disallow spaces between a function call
  no-trailing-spaces: error                # disallow trailing whitespace
  no-floating-decimal: error               # require floating decimals to be complete
  space-before-blocks: error               # require space before curly brace for blocks
  no-whitespace-before-property: error     # disallow whitespace before accessing properties
  one-var:                                 # require one variable declaration per let/const
    - error
    - never
  no-mixed-spaces-and-tabs:                # disallow tabs + spaces for indentation except for smart-tabs
    - error
    - smart-tabs
  no-multiple-empty-lines:                 # disallow more than one empty line
    - error
    - max: 1
  object-curly-spacing:                    # require space around curly braces for objects
    - error
    - always
  eol-last:                                # disallow new line after end of file
    - error
    - never
  padded-blocks:                           # disallow empty line in between blocks         
    - error
    - never
  indent:                                  # require tab for indentations
    - error
    - tab
    - SwitchCase: 1
  keyword-spacing:                         # require spaces before/after a keyword 
    - error
    - before: true
      after: true
  comma-spacing:                           # require space after a comma that is not the end of the line
    - error
    - before: false
      after: true
  curly:                                   # require curly braces for large blocks and consistent in branches
    - error
    - multi-or-nest
    - consistent
  quotes:                                  # require double-quotes instead of single
    - error
    - double
    - avoidEscape: true
  brace-style:                             # require opening brace on same line, ending brace on a new line
    - error
    - stroustrup
    - allowSingleLine: true
  semi:                                    # require semicolons for JS statements
    - error
    - always
    - omitLastInOneLineBlock: true
  max-len:                                 # require lines to be less than X characters
    - error
    - tabWidth: 3
    - code: 120
      comments: 160
      ignoreStrings: true
      ignoreTemplateLiterals: true
      ignoreTrailingComments: true
  # React-Native
  react-native/no-inline-styles: warn      # disallow inline styles
  # React
  react/jsx-uses-vars: error               # fix no-unused-vars for JSX expressions
  react/jsx-uses-react: error              # fix no-unused vars for React
  react/jsx-tag-spacing: error             # require consistent spaces before JSX tags
  react/jsx-no-duplicate-props: error      # disallow duplicate props
  react/jsx-equals-spacing:                # require spaces around equal signs for JSX
    - error
    - always
  react/jsx-curly-spacing:                 # object-curly-spacing for JSX expressions
    - error
    - when: always
      children: true
      attributes:
        allowMultiline: false
      spacing:
        objectLiterals: never