.eslintrc

{
"root": true,
  "env": {
    "browser": true,
    "es2020": true,
    "node": true,
    "jest": true,
    "jest/globals": true
  },
  "extends": [
    "eslint:recommended",
    "plugin:@typescript-eslint/eslint-recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:jest/recommended",
    "plugin:jest/style"
  ],
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaVersion": 11,
    "sourceType": "module",
    "project": "tsconfig.eslint.json"
  },
  "plugins": [
    "@typescript-eslint",
    "jest",
    "deprecation",
    "notice"
  ],
  "rules": {
    "@typescript-eslint/no-unused-vars": "error",
    "@typescript-eslint/explicit-function-return-type": "error",
    "@typescript-eslint/no-empty-function": [
      "error",
      {
        "allow": [
          "arrowFunctions"
        ]
      }
    ],
    "jest/no-disabled-tests": "warn",
    "jest/no-focused-tests": "error",
    "jest/no-identical-title": "error",
    "jest/prefer-to-have-length": "warn",
    "jest/valid-expect": "error",
    "deprecation/deprecation": "warn",
    "notice/notice": [
      "error",
      {
        "mustMatch": "Copyright \\(c\\) [0-9]{0,4}, Loïs Bégué",
        "template": "/**\n * treeifier \n *\n * License: MIT\n * Copyright (c) <%= YEAR %>, Loïs Bégué\n *\n**/\n"
      }
    ]
  }
}