consistent-return

要求 return 语句始终或从不指定值

与强制函数返回指定类型值的静态类型语言不同，JavaScript 允许函数中的不同代码路径返回不同类型的值。

JavaScript 的一个令人困惑的方面是，如果以下任何一项为真，则函数会返回 undefined：

• 它在退出之前不执行 return 语句
• 它执行没有明确指定值的 return
• 它执行 return undefined
• 它执行 return void 后跟一个表达式（例如，函数调用）
• 它执行 return 后跟任何其他计算结果为 undefined 的表达式

如果函数中的任何代码路径显式返回值，但某些代码路径没有显式返回值，则可能是输入错误，尤其是在大型函数中。在以下示例中：

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function doSomething(condition) {
    if (condition) {
        return true;
    } else {
        return;
    }
}

规则详情

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NrJkth/joQKVo0Sp81iI+A06i9GX/slD/1LexJqzFAoI1nFjlJjjk8Q+BydcruTg

/*eslint consistent-return: "error"*/

function doSomething(condition) {
    if (condition) {
        return true;
    } else {
        return;
    }
}

function doSomething(condition) {
    if (condition) {
        return true;
    }
}

DzO9VpSFHJiTjGCgt1KSooNhAIn1o64th84QTOygwWSy7fBgj4TGxtI1vaW0J9Ta

/*eslint consistent-return: "error"*/

function doSomething(condition) {
    if (condition) {
        return true;
    } else {
        return false;
    }
}

function Foo() {
    if (!(this instanceof Foo)) {
        return new Foo();
    }

    this.a = 0;
}

选项

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treatUndefinedAsUnspecified

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/*eslint consistent-return: ["error", { "treatUndefinedAsUnspecified": false }]*/

function foo(callback) {
    if (callback) {
        return void callback();
    }
    // no return statement
}

function bar(condition) {
    if (condition) {
        return undefined;
    }
    // no return statement
}

yqV+SV60QvsOsYXkYvZsZQ+NpoVwFXC3DZLqMSgjOQYETC14CDtQ4lsSl3/yns91YPVTqIugRVY8xCEs2V/wmOQdujHsSYWJ+XqCTgGsY5E1WTCYHYSEoDu/xDQmO2U1DwZHb1oPjewLDb1o8VeCww==

/*eslint consistent-return: ["error", { "treatUndefinedAsUnspecified": true }]*/

function foo(callback) {
    if (callback) {
        return void callback();
    }
    return true;
}

function bar(condition) {
    if (condition) {
        return undefined;
    }
    return true;
}

yqV+SV60QvsOsYXkYvZsZQ+NpoVwFXC3DZLqMSgjOQYETC14CDtQ4lsSl3/yns91YPVTqIugRVY8xCEs2V/wmGL/Giu8yCxAQZuYgFZoajk6OHyRYFK8V2NSOLybhVzIntQIpF74Hcpr4X2JZkRWwQ==

/*eslint consistent-return: ["error", { "treatUndefinedAsUnspecified": true }]*/

function foo(callback) {
    if (callback) {
        return void callback();
    }
    // no return statement
}

function bar(condition) {
    if (condition) {
        return undefined;
    }
    // no return statement
}

何时不使用

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