.eslintrc.js

module.exports = {
  parser: `@babel/eslint-parser`,
  extends: [
    `google`,
    `eslint:recommended`,
    `plugin:flowtype/recommended`,
    `plugin:react/recommended`,
    `prettier`,
  ],
  plugins: [`flowtype`, `prettier`, `react`, `filenames`, `@babel`],
  parserOptions: {
    ecmaVersion: 2023,
    sourceType: `module`,
    ecmaFeatures: {
      jsx: true,
    },
    babelOptions: {
      configFile: `./.babelrc.js`,
    },
  },
  env: {
    browser: true,
    es2023: true,
    node: true,
    jest: true,
  },
  globals: {
    before: true,
    after: true,
    spyOn: true,
    // These should be in scope but for some reason eslint can't see them
    NodeJS: true,
    JSX: true,
    NodeRequire: true,
    TimerHandler: true,
    __PATH_PREFIX__: true,
    __BASE_PATH__: true,
    __ASSET_PREFIX__: true,
    _CFLAGS_: true,
    __GATSBY: true,
  },
  rules: {
    "@babel/no-unused-expressions": [
      `error`,
      {
        allowTaggedTemplates: true,
      },
    ],
    "no-unused-expressions": `off`,
    "@babel/no-invalid-this": `error`,
    "no-invalid-this": `off`,
    "arrow-body-style": [
      `error`,
      `as-needed`,
      { requireReturnForObjectLiteral: true },
    ],
    "new-cap": `off`,
    "no-unused-vars": [
      `warn`,
      {
        varsIgnorePattern: `^_`,
        argsIgnorePattern: `^_`,
        ignoreRestSiblings: true,
      },
    ],
    "consistent-return": [`error`],
    "filenames/match-regex": [`error`, `^[a-z-\\d\\.]+$`, true],
    "no-console": `off`,
    "no-inner-declarations": `off`,
    "prettier/prettier": `error`,
    quotes: [`error`, `backtick`],
    "react/display-name": `off`,
    "react/jsx-key": `warn`,
    "react/no-unescaped-entities": `off`,
    "react/prop-types": `off`,
    "require-jsdoc": `off`,
    "valid-jsdoc": `off`,
    "prefer-promise-reject-errors": `warn`,
    "no-prototype-builtins": `warn`,
    "guard-for-in": `warn`,
    "spaced-comment": [
      `error`,
      `always`,
      { markers: [`/`], exceptions: [`*`, `+`] },
    ],
    camelcase: [
      `error`,
      {
        properties: `never`,
        ignoreDestructuring: true,
        allow: [`^unstable_`],
      },
    ],
  },
}