no-empty-function

禁止空函数

空函数会降低可读性，因为读者需要猜测它是否是故意的。所以为空函数写一个清晰的注释是一个好习惯。

function foo() {
    // do nothing.
}

特别是，箭头函数的空块可能会让开发人员感到困惑。它与空对象字面量非常相似。

list.map(() => {});   // This is a block, would return undefined.
list.map(() => ({})); // This is an empty object.

规则详情

该规则旨在消除空函数。如果函数包含注释，则不会将其视为问题。

此规则的错误代码示例：

/*eslint no-empty-function: "error"*/
/*eslint-env es6*/

function foo() {}

var foo = function() {};

var foo = () => {};

function* foo() {}

var foo = function*() {};

var obj = {
    foo: function() {},

    foo: function*() {},

    foo() {},

    *foo() {},

    get foo() {},

    set foo(value) {}
};

class A {
    constructor() {}

    foo() {}

    *foo() {}

    get foo() {}

    set foo(value) {}

    static foo() {}

    static *foo() {}

    static get foo() {}

    static set foo(value) {}
}

DzO9VpSFHJiTjGCgt1KSooNhAIn1o64th84QTOygwWSy7fBgj4TGxtI1vaW0J9Ta

/*eslint no-empty-function: "error"*/
/*eslint-env es6*/

function foo() {
    // do nothing.
}

var foo = function() {
    // any clear comments.
};

var foo = () => {
    bar();
};

function* foo() {
    // do nothing.
}

var foo = function*() {
    // do nothing.
};

var obj = {
    foo: function() {
        // do nothing.
    },

    foo: function*() {
        // do nothing.
    },

    foo() {
        // do nothing.
    },

    *foo() {
        // do nothing.
    },

    get foo() {
        // do nothing.
    },

    set foo(value) {
        // do nothing.
    }
};

class A {
    constructor() {
        // do nothing.
    }

    foo() {
        // do nothing.
    }

    *foo() {
        // do nothing.
    }

    get foo() {
        // do nothing.
    }

    set foo(value) {
        // do nothing.
    }

    static foo() {
        // do nothing.
    }

    static *foo() {
        // do nothing.
    }

    static get foo() {
        // do nothing.
    }

    static set foo(value) {
        // do nothing.
    }
}

选项

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allow: functions

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/*eslint no-empty-function: ["error", { "allow": ["functions"] }]*/

function foo() {}

var foo = function() {};

var obj = {
    foo: function() {}
};

allow: arrowFunctions

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/*eslint no-empty-function: ["error", { "allow": ["arrowFunctions"] }]*/
/*eslint-env es6*/

var foo = () => {};

allow: generatorFunctions

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/*eslint no-empty-function: ["error", { "allow": ["generatorFunctions"] }]*/
/*eslint-env es6*/

function* foo() {}

var foo = function*() {};

var obj = {
    foo: function*() {}
};

allow: methods

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/*eslint no-empty-function: ["error", { "allow": ["methods"] }]*/
/*eslint-env es6*/

var obj = {
    foo() {}
};

class A {
    foo() {}
    static foo() {}
}

allow: generatorMethods

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/*eslint no-empty-function: ["error", { "allow": ["generatorMethods"] }]*/
/*eslint-env es6*/

var obj = {
    *foo() {}
};

class A {
    *foo() {}
    static *foo() {}
}

allow: getters

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/*eslint no-empty-function: ["error", { "allow": ["getters"] }]*/
/*eslint-env es6*/

var obj = {
    get foo() {}
};

class A {
    get foo() {}
    static get foo() {}
}

allow: setters

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/*eslint no-empty-function: ["error", { "allow": ["setters"] }]*/
/*eslint-env es6*/

var obj = {
    set foo(value) {}
};

class A {
    set foo(value) {}
    static set foo(value) {}
}

allow: constructors

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/*eslint no-empty-function: ["error", { "allow": ["constructors"] }]*/
/*eslint-env es6*/

class A {
    constructor() {}
}

allow: asyncFunctions

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/*eslint no-empty-function: ["error", { "allow": ["asyncFunctions"] }]*/
/*eslint-env es2017*/

async function a(){}

allow: asyncMethods

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/*eslint no-empty-function: ["error", { "allow": ["asyncMethods"] }]*/
/*eslint-env es2017*/

var obj = {
    async foo() {}
};

class A {
    async foo() {}
    static async foo() {}
}

何时不使用

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