backend.eslintrc.json

{
  "env": {
    "es2021": true,
    "node": true
  },
  "extends": [
    "eslint:recommended",
    // Remove this:
    // "plugin:@typescript-eslint/recommended",
    // Add these:
    "plugin:@typescript-eslint/strict-type-checked",
    "plugin:@typescript-eslint/stylistic-type-checked",
    "plugin:import/recommended",
    "plugin:import/typescript",
    "prettier"
  ],
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaVersion": "latest",
    "sourceType": "module",
    // Add this:
    "project": true
  },
  "plugins": [
    "@typescript-eslint",
    // Add this:
    "import"
  ],
  "rules": {
    // Add all of these:

    // Uncomment this if you have verbatimModuleSyntax enabled and importing
    // .ts files with a .js extension gives lint errors.
    // "import/no-unresolved": "off",

    // Uncomment these if you really need to.
    // "@typescript-eslint/ban-ts-comment": "off",
    // "@typescript-eslint/no-explicit-any": "off",
    // "@typescript-eslint/no-non-null-assertion": "off",

    // Avoid bugs.
    "@typescript-eslint/no-shadow": ["error", { "ignoreTypeValueShadow": true }],
    "@typescript-eslint/no-unsafe-unary-minus": "error",
    "@typescript-eslint/no-unused-expressions": "error",
    "@typescript-eslint/no-unused-vars": [
      "error",
      {
        "argsIgnorePattern": "^_",
        "destructuredArrayIgnorePattern": "^_",
        "varsIgnorePattern": "^_"
      }
    ],
    "@typescript-eslint/switch-exhaustiveness-check": "error",
    "array-callback-return": "error",
    "eqeqeq": "error",
    "no-await-in-loop": "error",
    "no-constant-binary-expression": "error",
    "no-constructor-return": "error",
    "no-constant-condition": [
      "error",
      {
        "checkLoops": false
      }
    ],
    "no-promise-executor-return": "error",
    "no-self-compare": "error",
    "no-template-curly-in-string": "error",

    // Stylistic.
    "@typescript-eslint/consistent-type-definitions": ["warn", "type"],
    "@typescript-eslint/no-use-before-define": "warn",
    "@typescript-eslint/prefer-readonly": "warn",
    "@typescript-eslint/prefer-regexp-exec": "warn",
    "object-shorthand": ["warn", "properties"],
    "sort-imports": ["warn", { "ignoreDeclarationSort": true }],
    "import/consistent-type-specifier-style": ["warn", "prefer-top-level"],
    "import/order": [
      "warn",
      {
        "alphabetize": { "order": "asc" },
        "groups": ["builtin", "external", "parent", "sibling", "index", "object", "type"],
        "newlines-between": "always"
      }
    ],

    // Disabled because of too many false positives.
    "@typescript-eslint/no-unnecessary-condition": "off"
  }
}