.eslintrc

{
  "extends": ["airbnb", "react-app", "prettier"],
  "rules": {
    // Allow jsx tags inside .js files.
    "react/jsx-filename-extension": [
      1,
      {
        "extensions": [".js", ".jsx", ".tsx"]
      }
    ],
    // Disable props spreading (<App {...props} />) warning.
    "react/jsx-props-no-spreading": 0,
    // Throw warning instead of error when using array index as a key.
    "react/no-array-index-key": 1,
    // Enforce const `Component = (props) => {}` syntax
    "react/function-component-definition": [
      2,
      {
        "namedComponents": "arrow-function"
      }
    ],
    // Allow modules with named exports only.
    "import/prefer-default-export": 0,
    // Force {foo: 'bar'} object literal syntax.
    "object-curly-spacing": ["error", "never"],
    // Throw warning instead of error. Feel free to choose your favorite option https://eslint.org/docs/rules/arrow-body-style
    "arrow-body-style": ["warn", "as-needed"],
    // Make prettier code formatting suggestions more verbose.
    "prettier/prettier": [
      "warn",
      {
        "endOfLine": "auto"
      }
    ],
    // Throw warning when <a href="#"> or <a href="javascript:void(0)"> are used. Use <button> instead.
    "jsx-a11y/anchor-is-valid": [
      "warn",
      {
        "aspects": ["invalidHref"]
      }
    ],
    // Allow using (props) => <Component /> and ({propName}) => <Component /> syntax.
    "react/destructuring-assignment": "off",
    // Disable <Fragment> => <> replacement. Feel free to change
    "react/jsx-fragments": "off",
    // Below is the set of functional rules to warn developer about accidental mutations, which may cause error in reducers etc.
    // No delete operator.
    "fp/no-delete": "warn",
    // Warning when Object.assign(a, b) used, since it mutates first argument. Object.assign({}, a, b) is ok.
    "fp/no-mutating-assign": "warn",
    // Warning when mutating method (pop, push, reverse, shift, sort, splice, unshift, etc) is used. Ramda and lodash/fp are allowed (_.pop, R.push)
    "fp/no-mutating-methods": [
      "warn",
      {
        "allowedObjects": ["_", "R"]
      }
    ],
    // Warning when mutating operators (++, --, etc) are used, object = {} also. `Component.propTypes`, `Component.defaultProps`, common.js (`module.exports`) and `ref.current` are ok.
    "fp/no-mutation": [
      "warn",
      {
        "commonjs": true,
        "allowThis": true,
        "exceptions": [
          {
            "property": "propTypes"
          },
          {
            "property": "defaultProps"
          },
          {
            "property": "current"
          }
        ]
      }
    ],
    "import/extensions": [
      "error",
      "ignorePackages",
      {
        "js": "never",
        "jsx": "never",
        "ts": "never",
        "tsx": "never"
      }
    ],
    "no-shadow": "off",
    "@typescript-eslint/no-shadow": ["error"]
  },
  "plugins": ["prettier", "fp"],
  "settings": {
    "import/resolver": {
      "node": {
        "moduleDirectory": ["node_modules", "./src"]
      },
      "typescript": {}
    }
  },
  "overrides": [
    {
      "files": ["./*.js", "setupTests.js"],
      "rules": {
        "import/no-extraneous-dependencies": [
          "error",
          {
            "devDependencies": true,
            "optionalDependencies": false,
            "peerDependencies": false
          }
        ],
        "global-require": 0
      }
    },
    {
      "files": ["**/*.spec.js"],
      "rules": {
        "react/prop-types": "off"
      }
    },
    {
      "files": ["src/lib/**/*.js"],
      "rules": {
        "import/no-restricted-paths": [
          "error",
          {
            "zones": [
              {
                "target": "./src/lib",
                "from": "./src/environment"
              }
            ]
          }
        ]
      }
    },
    {
      "files": ["**/*.stories.*"],
      "rules": {
        "import/no-anonymous-default-export": "off"
      }
    }
  ],
  "ignorePatterns": ["/lib"]
}