extends: airbnb
parser: babel-eslint
# plugins:
#   - json
env:
  jest: true
  browser: true
settings:
  react:
    pragma: React
    version: 16.3
  import/resolver:
    webpack:
      config: 'config/webpack.config.prod.js'
rules:
# relaxations: rules we do not want to enforce
  no-underscore-dangle: 0 # do allow _myFunction (for "private" functions)
  prefer-destructuring: 0 # do allow {let a = someObj; return a.b;} instead of {let {b} = someObj; return b;}
  max-len: # do allow a little longer lines
    - error
    - { "code": 120 }
  no-param-reassign: # do allow function(a) {a.b = 123;}
    - error
    - { "props": false }
  no-mixed-operators: # do allow mathematically valid equations like a + b * c without writing parenthesis
    - error
    - {
        "groups": [
          ["&","|","^","~","<<",">>",">>>"],
          ["==","!=","===","!==",">",">=","<","<="],
          ["&&","||"],
          ["in","instanceof"]
        ],
        "allowSamePrecedence": true
      }
  react/jsx-filename-extension: 0 # do allow jsx code in files with .js extension
  import/prefer-default-export: 0 # do not force default export for single named export
  comma-dangle: 0 # do not enforce dangling commas
  class-methods-use-this: 0 # do not enforce static class utilization
  no-cond-assign: 0 # do not enforce while/do assignments
  jsx-a11y/no-static-element-interactions: 0 # do not force role declaration on static html elements, should be able deducted from context
  jsx-a11y/no-noninteractive-tabindex: 0 # react allows for regular html to have interactitivity
  consistent-return: 0 # do not force return in arrow functions
  react/no-array-index-key: 0 # do allow for keys to have array indexes, arrays dont necessary have some consistent identifier
  react/prefer-stateless-function: 0 # no error when a react component can be written as a pure function
  react/require-default-props: 0 # do allow non-required proptypes to be undefined in defaults (missing feature in prop-types)
  react/destructuring-assignment: 0 # do not enforce destructuring assignment of props
  react/jsx-one-expression-per-line: 0  # do not enforce one jsx expression per line
  implicit-arrow-linebreak: 0 # do not enforce fixed arrow function style, because this causes too long lines
  jsx-a11y/click-events-have-key-events: 0 # do allow for arbitrary components to have click events, without a matching key event
  import/no-cycle: 0 # usefull check. sometimes cyclic dependencies cause no issues though. disabled because took too long to check
  jsx-a11y/anchor-is-valid: 0 # anchors are valid click elements...
  react/sort-comp: # tweak to work around bug in eslint-react-plugin
    - "error"
    - {
        "order": [
          "static-methods",
          "instance-variables",
          "lifecycle",
          "instance-methods",
          "everything-else",
          "rendering"
        ],
        "groups": {
          "lifecycle": [
            "displayName",
            "propTypes",
            "contextTypes",
            "childContextTypes",
            "mixins",
            "statics",
            "defaultProps",
            "constructor",
            "getDefaultProps",
            "getInitialState",
            "state",
            "getChildContext",
            "componentWillMount",
            "componentDidMount",
            "componentWillReceiveProps",
            "shouldComponentUpdate",
            "componentWillUpdate",
            "componentDidUpdate",
            "componentWillUnmount"
          ],
          "rendering": [
            "/^render.+$/",
            "render"
          ]
        }
      }

# warnings allow building in development mode but not merging into develop
  no-debugger: 1 # do allow debugger in development mode
  react/prop-types: 1 # don't enforce prop-type checking in development mode
  no-unused-vars: # allow unused vars in development mode. do allow unused function arguments in production. e.g. to show that a function matches a specific signature
    - warn
    - { "vars": "all", "args": "none", "ignoreRestSiblings": true }
  react/no-unused-state: # allow unused state in development mode.
    - warn
  react/no-unused-prop-types: 1 # allow unused prop types in development mode
  no-sequences: 1 # allow sequences for debugging

# may/will be changed in the future
  no-console: 0 # do allow console statements (find a way to allow console statements in tests but not production code)
  react/forbid-prop-types:  # do allow "object" type props, because we want to be able to pass arbitrary json objects
    - error
    - {
        "forbid": ["any","array"]
      }
  import/no-extraneous-dependencies:
    - error
    - {
        "devDependencies": ["**/*.stories.js", "**/__tests__/**", "**/*.test.js"]
      }