useShorthandFunctionType

诊断类别：lint/style/useShorthandFunctionType

¥Diagnostic Category: lint/style/useShorthandFunctionType

TypeScript and TSX

自从：v1.5.0

¥Since: v1.5.0

来源：

¥Sources:

与以下相同：@typescript-eslint/prefer-function-type

¥Same as: @typescript-eslint/prefer-function-type

强制使用函数类型而不是带有调用签名的对象类型。

¥Enforce using function types instead of object type with call signatures.

TypeScript 允许两种常用方式来声明函数类型：

¥TypeScript allows for two common ways to declare a type for a function:

函数类型：() => string

¥Function type: () => string
具有签名的对象类型：{ (): string }

¥Object type with a signature: { (): string }

通常，如果可能，最好使用函数类型形式，因为它更简洁。

¥The function type form is generally preferred when possible for being more succinct.

此规则建议使用函数类型，而不是具有单个调用签名的接口或对象类型文字。

¥This rule suggests using a function type instead of an interface or object type literal with a single call signature.

示例

¥Examples

无效

¥Invalid

interface Example {
  (): string;
}

code-block.ts:2:3 lint/style/useShorthandFunctionType  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Use a function type instead of a call signature.
  
    1 │ interface Example {
  > 2 │   (): string;
      │   ^^^^^^^^^^^
    3 │ }
    4 │ 
  
  ℹ Types containing only a call signature can be shortened to a function type.
  
  ℹ Safe fix: Alias a function type instead of using an interface with a call signature.
  
    1   │ - interface·Example·{
    2   │ - ··():·string;
    3   │ - }
      1 │ + type·Example·=·()·=>·string
    4 2 │

function foo(example: { (): number }): number {
  return example();
}

code-block.ts:1:25 lint/style/useShorthandFunctionType  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Use a function type instead of a call signature.
  
  > 1 │ function foo(example: { (): number }): number {
      │                         ^^^^^^^^^^
    2 │   return example();
    3 │ }
  
  ℹ Types containing only a call signature can be shortened to a function type.
  
  ℹ Safe fix: Use a function type instead of an object type with a call signature.
  
    1   │ - function·foo(example:·{·():·number·}):·number·{
      1 │ + function·foo(example:·()·=>·number):·number·{
    2 2 │     return example();
    3 3 │   }

有效

¥Valid

type Example = () => string;

function foo(example: () => number): number {
  return bar();
}

// returns the function itself, not the `this` argument.
type ReturnsSelf2 = (arg: string) => ReturnsSelf;

interface Foo {
  bar: string;
}
interface Bar extends Foo {
  (): void;
}

// multiple call signatures (overloads) is allowed:
interface Overloaded {
  (data: string): number;
  (id: number): string;
}
// this is equivalent to Overloaded interface.
type Intersection = ((data: string) => number) & ((id: number) => string);

useShorthandFunctionType

示例

无效

有效

相关链接