.eslintrc.json

{
  "parser": "babel-eslint",
  "env": {
    "browser": true,
    "es6": true,
    "node": true
  },
  "extends": ["airbnb-base", "plugin:flowtype/recommended"],
  "plugins": ["flowtype"],
  "globals": {
    "Atomics": "readonly",
    "SharedArrayBuffer": "readonly"
  },
  "parserOptions": {
    "ecmaVersion": 2018,
    "sourceType": "module"
  },
  "rules": {
    "flowtype/boolean-style": [2, "boolean"],
    "flowtype/define-flow-type": 1,
    "flowtype/delimiter-dangle": [2, "never"],
    "flowtype/generic-spacing": [2, "never"],
    "flowtype/no-mixed": 2,
    "flowtype/no-primitive-constructor-types": 2,
    "flowtype/no-types-missing-file-annotation": 2,
    "flowtype/no-weak-types": 2,
    "flowtype/object-type-delimiter": [2, "comma"],
    "flowtype/require-parameter-type": 2,
    "flowtype/require-readonly-react-props": 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,
    "operator-linebreak": [
      "error",
      "after",
      {
        "overrides": {
          "?": "before",
          ":": "before"
        }
      }
    ],
    // "implicit-arrow-linebreak": ["error", "none"],
    "no-console": ["error", { "allow": ["warn", "error"] }],
    "quotes": ["error", "double", { "allowTemplateLiterals": true }]
  },
  "settings": {
    "flowtype": {
      "onlyFilesWithFlowAnnotation": false
    }
  }
}