no-setter-return

The "extends": "eslint:recommended" property in a configuration file enables this rule.

Disallows returning values from setters.

Setters cannot return values.

While returning a value from a setter does not produce an error, the returned value is being ignored. Therefore, returning a value from a setter is either unnecessary or a possible error, since the returned value cannot be used.

Rule Details

This rule disallows returning values from setters and reports return statements in setter functions.

Only return without a value is allowed, as it's a control flow statement.

This rule checks setters in:

Examples of incorrect code for this rule:

/*eslint no-setter-return: "error"*/

var foo = {
    set a(value) {
        this.val = value;
        return value;
    }
};

class Foo {
    set a(value) {
        this.val = value * 2;
        return this.val;
    }
}

const Bar = class {
    static set a(value) {
        if (value < 0) {
            this.val = 0;
            return 0;
        }
        this.val = value;
    }
};

Object.defineProperty(foo, "bar", {
    set(value) {
        if (value < 0) {
            return false;
        }
        this.val = value;
    }
});

Examples of correct code for this rule:

/*eslint no-setter-return: "error"*/

var foo = {
    set a(value) {
        this.val = value;
    }
};

class Foo {
    set a(value) {
        this.val = value * 2;
    }
}

const Bar = class {
    static set a(value) {
        if (value < 0) {
            this.val = 0;
            return;
        }
        this.val = value;
    }
};

Object.defineProperty(foo, "bar", {
    set(value) {
        if (value < 0) {
            throw new Error("Negative value.");
        }
        this.val = value;
    }
});

Further Reading

Version

This rule was introduced in ESLint 6.7.0.

Resources