.eslintrc

{
  "extends": "airbnb",
  "parser": "babel-eslint",
  "plugins": [
    "react",
    "jest",
    "flowtype"
  ],
  "env": {
    "es6": true,
    "browser": true,
    "node": true,
    "jest/globals": true
  },
  "globals": {
    "TimeoutID": true,
    "IntervalID": true,
    "AnimationFrameID": true
  },
  // custom rules
  "rules": {
    // http://eslint.org/docs/rules/comma-dangle
    // Custom rules for when trailing comma's are required
    "comma-dangle": ["error", {
      "arrays": "always-multiline",
      "objects": "always-multiline",
      "imports": "always-multiline",
      "exports": "always-multiline",
      "functions": "ignore"
    }],

    // https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/extensions.md
    // When importing files you do not need to add file extensions for the following extensions
    "import/extensions": ["error", "always", {
      "js": "never",
      "jsx": "never"
    }],

    // https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-extraneous-dependencies.md
    // Allowing importing from dev deps (for stories and tests)
    "import/no-extraneous-dependencies": "off",

    // http://eslint.org/docs/rules/no-plusplus
    // Allowing ++ on numbers
    "no-plusplus": "off",

    // http://eslint.org/docs/rules/no-param-reassign
    // Cannot reassign function parameters but allowing modification
    "no-param-reassign": ["error", { "props": false }],

    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-filename-extension.md
    // Allowing jsx in files with any file extension (old components have jsx but not the extension)
    "react/jsx-filename-extension": "off",

    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-sort-props.md
    // JSX props must be in alphabetical order
    // Disabled as this is creating too much noise in logs and is not being actively addressed
    "react/jsx-sort-props": "off",

    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-unknown-property.md
    // This was turned off for wc - but should be re-enabled eventually
    "react/no-unknown-property": ["off"],

    // http://eslint.org/docs/rules/no-multiple-empty-lines
    // Disallow more than 1 empty lines
    "no-multiple-empty-lines": ["error", { "max": 1 }],

    // http://eslint.org/docs/rules/padded-blocks
    // Enforce no padding within blocks
    "padded-blocks": ["error", "never"],

    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-unused-prop-types.md
    // Adding 'skipShapeProps' as the rule has issues with correctly handling PropTypes.shape
    "react/no-unused-prop-types": ["error", { "skipShapeProps": true }],

    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/prefer-stateless-function.md
    // Opt out of preferring stateless functions
    // Rationale: https://extranet.atlassian.com/display/AtlasKit/React+component+conventions
    "react/prefer-stateless-function": "off",

    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/require-default-props.md
    // default props not required for optional values
    "react/require-default-props": "off",

    // Disallowing the use of variables starting with `_` unless it called on `this`.
    // Allowed: `this._secret = Symbol()`
    // Not allowed: `const _secret = Symbol()`
    "no-underscore-dangle": ["error", { "allowAfterThis": true }],

    // Allowing warning and error console logging
    "no-console": ["error", { "allow": ["warn", "error"] }],

    // All blocks must be wrapped in curly braces {}
    // Preventing if(condition) return;
    // https://eslint.org/docs/rules/curly
    "curly": ["error", "all"],

    // Allowing Math.pow rather than forcing `**`
    // https://eslint.org/docs/rules/no-restricted-properties
    "no-restricted-properties": ["off", {
      "object": "Math",
      "property": "pow"
    }],

    // Opting out of prefer destructuring (nicer with flow in lots of cases)
    "prefer-destructuring": "off",

    // Opting out of specific object styles for now
    "object-curly-newline": "off",

    // Opting out of specific paren styles for now
    "function-paren-newline": "off",

    // Require // @flow at the top of files
    "flowtype/require-valid-file-annotation": ["error", "always", { "annotationStyle": "line" }]
  }
}