no-confusing-arrow

禁止使用可能与比较混淆的箭头函数

箭头函数 (=>) 在语法上类似于一些比较运算符（>、<、<= 和 >=）。此规则警告不要在可能与比较运算符混淆的地方使用箭头函数语法。

¥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.

这是一个示例，其中 => 的用法可能会令人困惑：

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

// 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;
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规则详情

¥Rule Details

此规则的错误代码示例：

¥Examples of incorrect code for this rule:

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

var x = a => 1 ? 2 : 3;
var x = (a) => 1 ? 2 : 3;
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此规则的正确代码示例：

¥Examples of correct code for this rule:

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

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

¥Options

此规则接受两个具有以下默认值的选项参数：

¥This rule accepts two options argument with the following defaults:

{
    "rules": {
        "no-confusing-arrow": [
            "error",
            { "allowParens": true, "onlyOneSimpleParam": false }
        ]
    }
}
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allowParens 是一个布尔设置，可以是 true（默认）或 false：

¥allowParens is a boolean setting that can be true(default) or false:

1. true 放宽了规则并接受括号作为有效的 “confusion-preventing” 语法。

   ¥true relaxes the rule and accepts parenthesis as a valid “confusion-preventing” syntax.

2. 即使表达式用括号括起来，false 也会触发警告

   ¥false warns even if the expression is wrapped in parenthesis

使用 {"allowParens": false} 选项的此规则的错误代码示例：

¥Examples of incorrect code for this rule with the {"allowParens": false} option:

/*eslint no-confusing-arrow: ["error", {"allowParens": false}]*/

var x = a => (1 ? 2 : 3);
var x = (a) => (1 ? 2 : 3);
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onlyOneSimpleParam 是一个布尔设置，可以是 true 或 false（默认）：

¥onlyOneSimpleParam is a boolean setting that can be true or false(default):

1. true 放宽规则，如果箭头函数有 0 个或 1 个以上的参数，或者参数不是标识符，则不报错。

   ¥true relaxes the rule and doesn’t report errors if the arrow function has 0 or more than 1 parameters, or the parameter is not an identifier.

2. 无论参数如何，false 都会触发警告。

   ¥false warns regardless of parameters.

使用 {"onlyOneSimpleParam": true} 选项的此规则的正确代码示例：

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

/*eslint no-confusing-arrow: ["error", {"onlyOneSimpleParam": true}]*/

() => 1 ? 2 : 3;
(a, b) => 1 ? 2 : 3;
(a = b) => 1 ? 2 : 3;
({ a }) => 1 ? 2 : 3;
([a]) => 1 ? 2 : 3;
(...a) => 1 ? 2 : 3;
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相关规则

• no-constant-condition
• arrow-parens

版本

此规则是在 ESLint v2.0.0-alpha-2 中引入。

资源

• 规则源码
• 测试源码