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no-empty-object-type

Disallow accidentally using the "empty object" type.

✅

在 ESLint 配置 中扩展"plugin:@typescript-eslint/recommended" 可启用此规则。

💡

此规则报告的一些问题可以通过编辑器 建议 手动修复。

TypeScript 中的 {} 或 "空对象" 类型是让不熟悉 TypeScript 结构类型的开发者感到困惑的常见原因。{} 表示任何非空值，包括像 0 和 "" 这样的文字：

¥The {}, or "empty object" type in TypeScript is a common source of confusion for developers unfamiliar with TypeScript's structural typing. {} represents any non-nullish value, including literals like 0 and "":

let anyNonNullishValue: {} = 'Intentionally allowed by TypeScript.';

通常，开发者编写 {} 的意思是：

¥Often, developers writing {} actually mean either:

  • object：表示任何对象值

    ¥object: representing any object value

  • unknown：表示任何值，包括 null 和 undefined

    ¥unknown: representing any value at all, including null and undefined

换句话说，"空对象" 类型 {} 实际上是 "任何已定义的值"。这包括数组、类实例、函数和原语，例如 string 和 symbol。

¥In other words, the "empty object" type {} really means "any value that is defined". That includes arrays, class instances, functions, and primitives such as string and symbol.

为了避免混淆 {} 类型允许任何非空值，此规则禁止使用 {} 类型。这包括没有字段的接口和对象类型别名。

¥To avoid confusion around the {} type allowing any non-nullish value, this rule bans usage of the {} type. That includes interfaces and object type aliases with no fields.

提示

如果你确实有一个允许 {} 的 API 用例，你始终可以配置 规则的选项、使用 ESLint 禁用注释 或 在你的 ESLint 配置。

¥If you do have a use case for an API allowing {}, you can always configure the rule's options, use an ESLint disable comment, or disable the rule in your ESLint config.

请注意，此规则不报告：

¥Note that this rule does not report on:

  • {} 作为交叉类型中的类型组成部分（例如，TypeScript 内置的 type NonNullable<T> = T & {} 之类的类型），因为这在类型系统操作中很有用。

    ¥{} as a type constituent in an intersection type (e.g. types like TypeScript's built-in type NonNullable<T> = T & {}), as this can be useful in type system operations.

  • 从多个其他接口扩展的接口。

    ¥Interfaces that extend from multiple other interfaces.

eslint.config.mjs
export default tseslint.config({
  rules: {
    "@typescript-eslint/no-empty-object-type": "error"
  }
});

在线运行试试这个规则 ↗

示例​

¥Examples

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

interface AnyObjectA {}
interface AnyValueA {}

type AnyObjectB = {};
type AnyValueB = {};
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选项​

该规则接受以下选项:

type Options = [
  {
    /** Whether to allow empty interfaces. */
    allowInterfaces?:
      | 'never'
      | 'with-single-extends'
      /** Whether to allow empty interfaces. */
      | 'always';
    /** Whether to allow empty object type literals. */
    allowObjectTypes?:
      | 'never'
      /** Whether to allow empty object type literals. */
      | 'always';
    /** A stringified regular expression to allow interfaces and object type aliases with the configured name. */
    allowWithName?: string;
  },
];

const defaultOptions: Options = [
  { allowInterfaces: 'never', allowObjectTypes: 'never' },
];

¥Options

默认情况下，此规则标记接口和对象类型。

¥By default, this rule flags both interfaces and object types.

allowInterfaces​

Whether to allow empty interfaces. Default: "never".

允许的值为：

¥Allowed values are:

  • 'always'：始终允许没有字段的接口

    ¥'always': to always allow interfaces with no fields

  • 'never'（默认）：绝不允许没有字段的接口

    ¥'never' (default): to never allow interfaces with no fields

  • 'with-single-extends'：允许从单个基本接口 extend 的空接口

    ¥'with-single-extends': to allow empty interfaces that extend from a single base interface

带有 { allowInterfaces: 'with-single-extends' } 的此规则的正确代码示例：

¥Examples of correct code for this rule with { allowInterfaces: 'with-single-extends' }:

interface Base {
  value: boolean;
}

interface Derived extends Base {}
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allowObjectTypes​

Whether to allow empty object type literals. Default: "never".

允许的值为：

¥Allowed values are:

  • 'always'：始终允许没有字段的对象类型文字

    ¥'always': to always allow object type literals with no fields

  • 'never'（默认）：绝不允许没有字段的对象类型文字

    ¥'never' (default): to never allow object type literals with no fields

allowWithName​

A stringified regular expression to allow interfaces and object type aliases with the configured name.

如果你现有的代码样式包括使用 {} 而不是 object 声明空类型的模式，这可能很有用。

¥This can be useful if your existing code style includes a pattern of declaring empty types with {} instead of object.

带有 { allowWithName: 'Props$' } 的此规则的代码示例：

¥Examples of code for this rule with { allowWithName: 'Props$' }:

interface InterfaceValue {}

type TypeValue = {};
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何时不使用它​

¥When Not To Use It

如果你的代码通常需要表示 "任何非空值" 类型，则此规则可能不适合你。广泛使用类型操作（例如条件类型和映射类型）的项目通常会受益于禁用此规则。

¥If your code commonly needs to represent the "any non-nullish value" type, this rule may not be for you. Projects that extensively use type operations such as conditional types and mapped types oftentimes benefit from disabling this rule.

进一步阅读​

¥Further Reading

'## 资源'