.eslintrc.json

{
  "env": {
    "es6": true,
    "jest": true,
    "node": true
  },
  "extends": [
    "eslint:recommended",
    "airbnb-base",
    "plugin:@typescript-eslint/recommended",
    "plugin:import/errors",
    "plugin:import/warnings",
    "plugin:jest/all",
    "plugin:node/recommended",
    "plugin:prettier/recommended" // Enables eslint-plugin-prettier and displays prettier errors as ESLint errors. Make sure this is always the last configuration in the extends array.
  ],
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaVersion": 2018,
    "sourceType": "module"
  },
  "plugins": [
    "@typescript-eslint",
    "import",
    "jest", // relevancy to ensure correct unit tests to be evaluated
    "node",
    "prefer-arrow",
    "prettier"
  ],
  "settings": {
    "import/parsers": {
      "@typescript-eslint/parser": [".ts", ".tsx"]
    },
    "import/resolver": {
      // use <root>/tsconfig.json
      "typescript": {
        "alwaysTryTypes": true // always try to resolve types under `<roo/>@types` directory even it doesn't contain any source code, like `@types/unist`
      }
    },
    "node": {
      "tryExtensions": [".ts", ".js", ".json"]
    }
  },
  "reportUnusedDisableDirectives": true,
  "rules": {
    "@typescript-eslint/interface-name-prefix": 0,
    "@typescript-eslint/no-use-before-define": 1,

    "class-methods-use-this": 1,
    // "func-names": 0,
    "global-require": 1,
    "guard-for-in": 1,
    "max-classes-per-file": 0,
    "no-array-constructor": 1,
    "no-continue": 1,
    "no-nested-ternary": 1,
    "no-param-reassign": 1,
    "no-plusplus": 1,
    "no-process-exit": 1,
    "no-proto": 1,
    "no-restricted-syntax": [
      "error",
      {
        "selector": "ForInStatement",
        "message": "for..in loops iterate over the entire prototype chain, which is virtually never what you want. Use Object.{keys,values,entries}, and iterate over the resulting array."
      },
      {
        "selector": "LabeledStatement",
        "message": "Labels are a form of GOTO; using them makes code confusing and hard to maintain and understand."
      },
      {
        "selector": "WithStatement",
        "message": "`with` is disallowed in strict mode because it makes code impossible to predict and optimize."
      }
    ],
    "no-return-assign": 1,
    "no-underscore-dangle": 1,
    "no-unreachable": 1,
    "no-unused-vars": 0,
    "no-use-before-define": 0,
    "prefer-destructuring": 1,
    // "prefer-object-spread": 0,
    "prefer-rest-params": 1,
    "prefer-spread": 1,
    "strict": 0,
    "valid-typeof": 1,
    "vars-on-top": 1,

    // eslint-plugin-es - https://mysticatea.github.io/eslint-plugin-es/

    // eslint-plugin-import rules - https://github.com/benmosher/eslint-plugin-import/blob/master/README.md
    "import/extensions": ["error", { "ts": "never" }],
    "import/no-dynamic-require": 1,
    "import/no-extraneous-dependencies": 0,
    "import/prefer-default-export": 0,

    // eslint-plugin-jest - https://github.com/jest-community/eslint-plugin-jest/blob/master/README.md
    "jest/expect-expect": 1,
    "jest/no-test-return-statement": 1,
    "jest/no-truthy-falsy": 1,
    "jest/prefer-called-with": 1,
    "jest/prefer-expect-assertions": 0,
    "jest/require-to-throw-message": 1,
    "jest/require-top-level-describe": 1,
    "jest/no-export": 1,

    // for reference. Might be useful with switch to Typescript
    // eslint-plugin-jsdoc - https://github.com/gajus/eslint-plugin-jsdoc/blob/master/README.md

    // eslint-plugin-node - https://github.com/mysticatea/eslint-plugin-node
    "node/no-extraneous-import": ["error", { "allowModules": ["ts-essentials"] }],
    "node/no-unpublished-require": 1,
    "node/no-unsupported-features/es-syntax": 0,
    "node/no-deprecated-api": 1,
    "prettier/prettier": "error"
  }
}