Don't print an error on unused params in ES5 setters

[mgol]

The following code:

(function () {
    "use strict";

    var o = {
        set b(a) {
        }
    };

    o.b = 2;
})();

triggers the error:

5:8 - a is defined but never used

In ES5 setters parameter is required, though and you can imagine a scenario where you want to use a setter without using the parameter.

This is similar to try {...} catch (e) {} where you need the parameter as well even if you don't need it. ESLint doesn't error on unused catch parameter.

The example was run on http://eslint.org/demo/.

[BenoitZugmeyer]

Just passing by:

though and you can imagine a scenario where you want to use a setter without using the parameter.

I can't imagine such scenario and I'm curious, what is your use case?

[mgol]

I can't imagine such scenario and I'm curious, what is your use case?

One example is if you have to work in non-strict code and you still want to have a particular setter to throw:

var o = {
    get x() {return 2;}
    set x(v) {throw new Error('o.x cannot be modified!');}
};
console.log(o.x);
o.x = 3;

[BenoitZugmeyer]

Nice, thank you!

[nzakas]

Yeah, I think the analogy of catch is spot-on. You literally have no choice but to provide the argument even if you arent going to use it. We should just skip checking it.

[nzakas]

Working on this.