#no-empty-object-type

#Configuration

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/no-empty-object-type': 'error',
    },
  },
]);

#Rule Details

Disallows accidental uses of the {} ("empty object") type. In TypeScript {} is the type of any non-nullish value, which is rarely what authors intend — typically they want object (any non-primitive value) or unknown (any value at all). The same problem applies to empty interface declarations: an empty interface with no members is equivalent to {}, and an empty interface that extends a single supertype is equivalent to a type alias of that supertype.

This rule reports both shapes and offers object / unknown suggestions.

Examples of incorrect code for this rule:

let anyObject: {};
let anyValue: {};

interface AnyObject {}
interface AnyValue {}

type AnyObjectAlias = {};
type AnyValueAlias = {};

Examples of correct code for this rule:

let anyObject: object;
let anyValue: unknown;

type AnyObjectAlias = object;
type AnyValueAlias = unknown;

let objectWith: {
  property: boolean;
};

interface InterfaceWith {
  property: boolean;
}

type TypeWith = {
  property: boolean;
};

#Options

• allowInterfaces (default "never"): how empty interfaces are treated.
  • "never": empty interfaces are disallowed.
  • "always": empty interfaces are always allowed.
  • "with-single-extends": empty interfaces are allowed only when they extend exactly one supertype.
• allowObjectTypes (default "never"): how empty {} type literals are treated.
  • "never": empty {} is disallowed.
  • "always": empty {} is always allowed.
• allowWithName: a regular expression source string. When set, interfaces and type aliases whose name matches the pattern are exempted.

#allowInterfaces: "with-single-extends"

Examples of correct code:

interface Base {
  value: boolean;
}

interface Derived extends Base {}

#allowObjectTypes: "always"

Examples of correct code:

type AnyObject = {};

let value: {};

#allowWithName: "Props$"

Examples of correct code:

interface ComponentProps {}

type DialogProps = {};

#Original Documentation

• typescript-eslint no-empty-object-type