.eslintrc.json

{
  "env": {
    "browser": true,
    "es2021": true,
    "jest": true
  },
  "extends": [
    "plugin:react/recommended",
    "airbnb",
    "plugin:prettier/recommended"
  ],
  "overrides": [
    {
      "files": ["route.js"],
      "rules": {
        "import/prefer-default-export": "off"
      }
    },
    {
      "files": ["__tests__/*.t.js", "__tests__/*.test.js"],
      "rules": {
        "react/jsx-filename-extension": "off"
      }
    }
  ],
  "parserOptions": {
    "ecmaVersion": "latest",
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true
    }
  },
  "plugins": ["react"],
  "rules": {
    "react/react-in-jsx-scope": "off",
    "react/jsx-curly-brace-presence": "off",
    "react/prop-types": "warn",
    "react/require-default-props": "off", // obsolete rule
    "no-unused-vars": "warn",
    "no-console": "warn",
    "import/no-extraneous-dependencies": "off",
    "no-plusplus": "off",

    // https://stackoverflow.com/a/72643821
    "import/extensions": [
      "error",
      "ignorePackages",
      {
        "": "never",
        "js": "never",
        "jsx": "never"
      }
    ],

    // https://github.com/firebase/firebase-admin-node/discussions/1359#discussioncomment-977900
    "import/no-unresolved": [
      "error",
      {
        "ignore": ["^@/.+"]
      }
    ]
  }
}