.eslintrc.js

module.exports = {
  parser: "@typescript-eslint/parser",
  parserOptions: {
    project: "./tsconfig.eslint.json",
    sourceType: "module",
  },
  env: {
    commonjs: true,
    mocha: true,
  },
  plugins: ["@typescript-eslint"],
  extends: [
    "eslint:recommended",
    "plugin:@typescript-eslint/eslint-recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:@typescript-eslint/recommended-requiring-type-checking",
    "prettier",
  ],
  rules: {
    "@typescript-eslint/no-unused-vars": [
      "warn",
      { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
    ],
    "@typescript-eslint/restrict-plus-operands": 0, // A lot of strings are built with +
    "@typescript-eslint/no-this-alias": 0, // `this` is aliased in several places
    "no-unused-expressions": "off",
    "@typescript-eslint/no-unused-expressions": ["error"],
    "@typescript-eslint/unbound-method": [
      "error",
      {
        ignoreStatic: true,
      },
    ],
  },
};