.eslintrc.js

module.exports = {
  parser: "@typescript-eslint/parser",
  parserOptions: {
    ecmaVersion: 12,
    sourceType: "module",
  },
  plugins: ["@typescript-eslint", "jest"],
  extends: [
    "eslint:recommended",
    "plugin:@typescript-eslint/recommended",
    "prettier",
  ],
  rules: {
    "@typescript-eslint/no-unused-vars": "error",
    // to enforce using type for object type definitions, can be type or interface
    "@typescript-eslint/consistent-type-definitions": ["error", "type"],
  },

  env: {
    node: true,
    es2021: true,
    "jest/globals": true,
  },
  overrides: [
    {
      files: ["**/**.spec.ts"],
      plugins: ["jest"],
      extends: ["plugin:jest/recommended"],
      rules: {
        "jest/prefer-expect-assertions": "off",
        "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",
      },
    },
  ],
};