.eslintrc.js

module.exports = {
  root: true,
  env: {
    node: true,
    es6: true,
    jest: true,
  },
  parser: "@typescript-eslint/parser",
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: "module",
  },
  extends: ["eslint:recommended", "plugin:prettier/recommended"],
  overrides: [
    {
      files: ["**/*.ts"],
      extends: [
        "eslint:recommended",
        "plugin:@typescript-eslint/eslint-recommended",
        "plugin:@typescript-eslint/recommended",
        "prettier/@typescript-eslint",
        "plugin:jest/recommended",
      ],
      plugins: ["@typescript-eslint", "jest"],
      rules: {
        "@typescript-eslint/explicit-function-return-type": [
          "warn",
          {
            allowExpressions: true,
          },
        ],
        "@typescript-eslint/no-unused-vars": "warn",
        "@typescript-eslint/no-use-before-define": "off",
        "no-console": "error",
        // nededed for mixins to avoid unecessary warnings
        "@typescript-eslint/no-empty-interface": "off",
      },
    },
  ],
}