class-methods-use-this

强制类方法使用 this

如果一个类方法不使用this，有时可以做成静态函数。如果您确实将该方法转换为静态函数，则调用该特定方法的类的实例也必须转换为静态调用（MyClass.callStaticMethod()）

可能有一个不使用 this 的类方法，例如：

class A {
    constructor() {
        this.a = "hi";
    }

    print() {
        console.log(this.a);
    }

    sayHi() {
        console.log("hi");
    }
}

let a = new A();
a.sayHi(); // => "hi"

在上面的例子中，sayHi 方法没有使用 this，所以我们可以把它变成一个静态方法：

class A {
    constructor() {
        this.a = "hi";
    }

    print() {
        console.log(this.a);
    }

    static sayHi() {
        console.log("hi");
    }
}

A.sayHi(); // => "hi"

还要注意，在上面的示例中，如果将方法切换为静态方法，则必须将调用静态方法 (let a = new A(); a.sayHi();) 的类的实例更新为静态调用 (A.sayHi();)，而不是使用类调用的实例方法

规则详情

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53qbJC6xNcTpfWzDOxH3FbxQniXPcALMzc0838bz9bxwfaPpKG0ZV7pRGyxgA1aA

/*eslint class-methods-use-this: "error"*/
/*eslint-env es6*/

class A {
    foo() {
        console.log("Hello World");     /*error Expected 'this' to be used by class method 'foo'.*/
    }
}

x8vS/D2xVZSiiHLs1PwUl6/TVEXV0uticb8dGcMm9rxiwxh8yRqnjwkHP0i+2Pam

/*eslint class-methods-use-this: "error"*/
/*eslint-env es6*/
class A {
    foo() {
        this.bar = "Hello World"; // OK, this is used
    }
}

class A {
    constructor() {
        // OK. constructor is exempt
    }
}

class A {
    static foo() {
        // OK. static methods aren't expected to use this.
    }

    static {
        // OK. static blocks are exempt.
    }
}

选项

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exceptMethods

"class-methods-use-this": [<enabled>, { "exceptMethods": [<...exceptions>] }]

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/*eslint class-methods-use-this: "error"*/

class A {
    foo() {
    }
}

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/*eslint class-methods-use-this: ["error", { "exceptMethods": ["foo", "#bar"] }] */

class A {
    foo() {
    }
    #bar() {
    }
}

enforceForClassFields

"class-methods-use-this": [<enabled>, { "enforceForClassFields": true | false }]

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/*eslint class-methods-use-this: ["error", { "enforceForClassFields": true }] */

class A {
    foo = () => {}
}

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/*eslint class-methods-use-this: ["error", { "enforceForClassFields": true }] */

class A {
    foo = () => {this;}
}

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/*eslint class-methods-use-this: ["error", { "enforceForClassFields": false }] */

class A {
    foo = () => {}
}