.eslintrc.json

{
  "root": true,

  "parser": "@typescript-eslint/parser", // Specifies the ESLint parser

  "plugins": ["@typescript-eslint", "jest", "import", "sonarjs"],

  "env": {
    "node": true,
    "es6": true,
    "jest": true
  },

  "globals": {
    "Atomics": "readonly"
  },

  "parserOptions": {
    "ecmaVersion": 2020, // Allows for the parsing of modern ECMAScript features
    "sourceType": "module", // Allows for the use of imports
    "project": "./tsconfig.json",
    "ecmaFeatures": {
      "impliedStrict": true
    }
  },

  "settings": {
    "import/resolver": {
      "node": {
        "paths": ["src"],
        "extensions": [".js", ".ts"]
      }
    },
    "import/parsers": {
      "@typescript-eslint/parser": [".ts"]
    },
    "import/extensions": [".js", ".ts"]
  },

  "extends": [
    "eslint:all",
    "airbnb-typescript/base",

    "plugin:@typescript-eslint/eslint-recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:@typescript-eslint/recommended-requiring-type-checking",

    "plugin:import/errors",
    "plugin:import/warnings",
    "plugin:import/typescript",

    "plugin:jest/all",
    "plugin:promise/recommended",
    "plugin:unicorn/recommended",
    "plugin:sonarjs/recommended",

    "plugin:prettier/recommended",
    "prettier/@typescript-eslint",
    "prettier"
  ],

  "rules": {
    // Place to specify ESLint rules. Can be used to overwrite rules specified from the extended configs
    // e.g. "@typescript-eslint/explicit-function-return-type": "off",

    // Too restrictive, writing ugly code to defend against a very unlikely scenario: https://eslint.org/docs/rules/no-prototype-builtins
    "no-prototype-builtins": "off",
    // https://basarat.gitbooks.io/typescript/docs/tips/defaultIsBad.html
    "import/prefer-default-export": "off",
    "import/no-default-export": "error",
    // Use function hoisting to improve code readability
    "no-use-before-define": [
      "error",
      { "functions": false, "classes": true, "variables": true }
    ],
    // Makes no sense to allow type inferrence for expression parameters, but require typing the response
    "@typescript-eslint/explicit-function-return-type": [
      "error",
      { "allowExpressions": true, "allowTypedFunctionExpressions": true }
    ],
    "@typescript-eslint/no-use-before-define": [
      "error",
      {
        "functions": false,
        "classes": true,
        "variables": true,
        "typedefs": true
      }
    ],

    "@typescript-eslint/member-delimiter-style": [
      "error",
      {
        "multiline": {
          "delimiter": "none",
          "requireLast": false
        },
        "singleline": {
          "delimiter": "semi",
          "requireLast": false
        }
      }
    ],
    "@typescript-eslint/semi": ["off"],
    "callback-return": "warn",
    "default-param-last": ["warn"],
    "func-style": [
      "error",
      "declaration",
      {
        "allowArrowFunctions": true
      }
    ],
    "import/extensions": ["warn", "never"],
    "import/order": [
      "error",
      {
        "alphabetize": {
          "caseInsensitive": true,
          "order": "asc"
        },
        "groups": [
          "builtin",
          "external",
          "parent",
          "sibling",
          "index",
          "internal"
        ],
        "newlines-between": "always-and-inside-groups"
      }
    ],
    "no-magic-numbers": [
      "warn",
      {
        "enforceConst": true,
        "ignoreArrayIndexes": true
      }
    ],
    "no-process-env": "off",
    "no-ternary": "off",
    "one-var": [
      "error",
      {
        "const": "never",
        "let": "never",
        "separateRequires": true,
        "var": "always"
      }
    ],
    "prettier/prettier": "warn",

    "semi": "off",
    "sort-imports": [
      "error",
      {
        "ignoreCase": false,
        "ignoreDeclarationSort": true,
        "ignoreMemberSort": false,
        "memberSyntaxSortOrder": ["none", "all", "multiple", "single"]
      }
    ],
    "sort-keys": [
      "warn",
      "asc",
      {
        "caseSensitive": true,
        "minKeys": 2,
        "natural": true
      }
    ],
    "unicorn/consistent-function-scoping": "off",
    "unicorn/filename-case": [
      "error",
      {
        "case": "kebabCase"
      }
    ],
    "unicorn/prevent-abbreviations": [
      "error",
      {
        "whitelist": {
          "props": true
        }
      }
    ],

    // TypeScript's `noFallthroughCasesInSwitch` option is more robust (#6906)
    "default-case": "off",
    // 'tsc' already handles this (https://github.com/typescript-eslint/typescript-eslint/issues/291)
    "no-dupe-class-members": "off",
    // 'tsc' already handles this (https://github.com/typescript-eslint/typescript-eslint/issues/477)
    "no-undef": "off",

    // Add TypeScript specific rules (and turn off ESLint equivalents)
    "@typescript-eslint/consistent-type-assertions": "warn",
    "no-array-constructor": "off",
    "@typescript-eslint/no-array-constructor": "warn",
    "no-unused-expressions": "off",
    "@typescript-eslint/no-unused-expressions": [
      "error",
      {
        "allowShortCircuit": true,
        "allowTernary": true,
        "allowTaggedTemplates": true
      }
    ],
    "no-unused-vars": "off",
    "@typescript-eslint/no-unused-vars": [
      "warn",
      {
        "args": "none",
        "ignoreRestSiblings": true
      }
    ],
    "no-useless-constructor": "off",
    "@typescript-eslint/no-useless-constructor": "warn"
  }
}