Disallow arrow functions where they could be confused with comparisons (no-confusing-arrow)

禁止在可能与比较操作符相混淆的地方使用箭头函数 (no-confusing-arrow)

The --fix option on the command line can automatically fix some of the problems reported by this rule.

命令行中的 --fix 选项可以自动修复一些该规则报告的问题。

Arrow functions (=>) are similar in syntax to some comparison operators (>, <, <=, and >=). This rule warns against using the arrow function syntax in places where it could be confused with a comparison operator. Even if the arguments of the arrow function are wrapped with parens, this rule still warns about it unless allowParens is set to true.

箭头函数(=>) 在语法上与一些比较操作符(><<=>=)相似。当与比较操作符混淆的地方使用箭头函数语法,该规则会发出警告。即使箭头函数是用括号括起来的,该规则仍会发出警告,除非 allowParens 被设置为 true

Here’s an example where the usage of => could be confusing:

下面的例子使用 => 可能会让人感到困惑:

// The intent is not clear
var x = a => 1 ? 2 : 3;
// Did the author mean this
var x = function (a) { return 1 ? 2 : 3 };
// Or this
var x = a <= 1 ? 2 : 3;

Rule Details

Examples of incorrect code for this rule:

错误 代码示例:

/*eslint no-confusing-arrow: "error"*/
/*eslint-env es6*/

var x = a => 1 ? 2 : 3;
var x = (a) => 1 ? 2 : 3;
var x = (a) => (1 ? 2 : 3);

Examples of correct code for this rule:

正确 代码示例:

/*eslint no-confusing-arrow: "error"*/
/*eslint-env es6*/

var x = a => { return 1 ? 2 : 3; };
var x = (a) => { return 1 ? 2 : 3; };

Options

This rule accepts a single options argument with the following defaults:

该规则只接收一个选项参数,使用下面的默认值:

{
    "rules": {
        "no-confusing-arrow": ["error", {"allowParens": false}]
    }
}

allowParens is a boolean setting that can be true or false:

allowParens 是一个布尔类型的设置,可以使 truefalse

  1. true relaxes the rule and accepts parenthesis as a valid “confusion-preventing” syntax.
  2. true 使该规则不那么严格,将括号作为有效防止混淆的语法。
  3. false warns even if the expression is wrapped in parenthesis
  4. false 即使表达式括在括号中也发出警告

Examples of correct code for this rule with the {"allowParens": true} option:

选项 {"allowParens": true}正确 代码示例:

/*eslint no-confusing-arrow: ["error", {"allowParens": true}]*/
/*eslint-env es6*/
var x = a => (1 ? 2 : 3);
var x = (a) => (1 ? 2 : 3);

Version

This rule was introduced in ESLint 2.0.0-alpha-2.

该规则在 ESLint 2.0.0-alpha-2 中被引入。

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