.eslintrc.json

{
  "parser": "babel-eslint",
  "extends": "eslint:recommended",
  "parserOptions": {
    "ecmaVersion": 6,
    "sourceType": "module",
    "allowImportExportEverywhere": true,
    "ecmaFeatures": {
      "experimentalObjectRestSpread": true,
      "jsx": true
    }
  },
  "globals": {
  },
  "env": {
    "es6": true,
    "browser": true,
    "node": true,
    "amd": true,
    "jquery": true
  },
  "plugins": [
    "flowtype"
  ],
  "rules": {
    "indent": ["error", 2, { "SwitchCase": 1 }],
    "linebreak-style": ["error", "unix"],
    "no-cond-assign": ["error", "always"],
    "no-console": "off",
    "no-plusplus": "off",
    "quotes": ["error", "single", { "avoidEscape": true }],
    "semi": ["error", "always"],
    "strict": "off",

    "flowtype/boolean-style": [2, "boolean"],
    "flowtype/define-flow-type": 1,
    "flowtype/delimiter-dangle": [2, "never"],
    "flowtype/generic-spacing": [2, "never"],
    "flowtype/no-primitive-constructor-types": 2,
    "flowtype/no-weak-types": 0,
    "flowtype/object-type-delimiter": [2, "comma"],
    "flowtype/require-parameter-type": 0,
    "flowtype/require-return-type": [2, "always", {"annotateUndefined": "never"} ],
    "flowtype/require-valid-file-annotation": 2,
    "flowtype/semi": [2, "always"],
    "flowtype/space-after-type-colon": [2, "always"],
    "flowtype/space-before-generic-bracket": [2, "never"],
    "flowtype/space-before-type-colon": [2, "never"],
    "flowtype/type-id-match": [2, "^([A-Z][a-z0-9]+)+Type$"],
    "flowtype/union-intersection-spacing": [2, "always"],
    "flowtype/use-flow-type": 1,
    "flowtype/valid-syntax": 1
  },
  "settings": {
    "flowtype": {
      "onlyFilesWithFlowAnnotation": true
    }
  }
}