useArrowFunction

诊断类别：lint/complexity/useArrowFunction

¥Diagnostic Category: lint/complexity/useArrowFunction

JavaScript (and super languages)

自从：v1.0.0

¥Since: v1.0.0

来源：

¥Sources:

灵感来自：prefer-arrow-callback

¥Inspired from: prefer-arrow-callback

在函数表达式上使用箭头函数。

¥Use arrow functions over function expressions.

箭头函数表达式是正则函数表达式的紧凑替代，但有一个重要区别：this 不绑定到箭头函数。它从其父范围继承 this。

¥An arrow function expression is a compact alternative to a regular function expression, with an important distinction: this is not bound to the arrow function. It inherits this from its parent scope.

此规则建议将所有不是生成器（function*）且不使用 this 的函数表达式转换为箭头函数。

¥This rule proposes turning all function expressions that are not generators (function*) and don’t use this into arrow functions.

示例

¥Examples

无效

¥Invalid

const z = function() {
    return 0;
}

code-block.js:1:11 lint/complexity/useArrowFunction  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This function expression can be turned into an arrow function.
  
  > 1 │ const z = function() {
      │           ^^^^^^^^^^^^
  > 2 │     return 0;
  > 3 │ }
      │ ^
    4 │ 
  
  ℹ Function expressions that don’t use this can be turned into arrow functions.
  
  ℹ Safe fix: Use an arrow function instead.
  
    1   │ - const·z·=·function()·{
    2   │ - ····return·0;
    3   │ - }
      1 │ + const·z·=·()·=>·0
    4 2 │

const delegatedFetch = async function(url) {
    return await fetch(url);
}

code-block.js:1:24 lint/complexity/useArrowFunction  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This function expression can be turned into an arrow function.
  
  > 1 │ const delegatedFetch = async function(url) {
      │                        ^^^^^^^^^^^^^^^^^^^^^
  > 2 │     return await fetch(url);
  > 3 │ }
      │ ^
    4 │ 
  
  ℹ Function expressions that don’t use this can be turned into arrow functions.
  
  ℹ Safe fix: Use an arrow function instead.
  
    1   │ - const·delegatedFetch·=·async·function(url)·{
    2   │ - ····return·await·fetch(url);
    3   │ - }
      1 │ + const·delegatedFetch·=·async·(url)·=>·await·fetch(url)
    4 2 │

有效

¥Valid

const f = function() {
    return this.prop;
}

忽略命名函数表达式：

¥Named function expressions are ignored:

const z = function z() {
    return 0;
}

声明 this 类型的函数表达式也会被忽略：

¥Function expressions that declare the type of this are also ignored:

const z = function(this: A): number {
    return 0;
}

useArrowFunction

示例

无效

有效

相关链接