How do I get the Closure Compiler to stop complaining about union types when calling a function?

Question

I'm seeing this in particular when using the jQuery-1.4.3 externs file. The javadocs for that reads

/**
 * @param {(string|number|function(number,number))=} arg1
 * @return {(number|jQueryObject)}
 * @nosideeffects
 */
jQueryObject.prototype.width = function(arg1) {};

I have a call that looks like this:

   var w =  $(window).width();
    $('#whatever').width(w)

Closure complains: WARNING - actual parameter 1 of jQueryObject.prototype.height does not match formal parameter found : (jQueryObject|null|number) required: (function (number, number): ?|number|string|undefined) $('#Xobni').height($(window).height());

From playing around (removing the possible return types), I can see that the problem is that the first call to width can return possibly a jQueryObject, and since that's not a valid input, Closure gives me an error. I tried adding this:

/**
 * @type {number}
 */
var w =  $(window).width();
$('#Xobni').width(w);

But then Closure complains: WARNING - initializing variable found : (jQueryObject|null|number) required: number var w = $(window).width();

The problem is that when width takes an argument, it returns a jQueryObject. When it doesn't take an argument, it returns a number. So I know my call is okay, but the javadocs don't quite reflect that, and so Closure is warning me. Is there a way to fix up the javadocs appropriately or a way to tell Closure I know this result will be a number. I know I can probably suppress the error, but I'd like to know how to annotate these things better.

Thanks for the help!

Answer 1

Try this:

var w =  $(window).width();
w = parseInt(w.toString());
$('#whatever').width(w);

or this:

var w =  $(window).width() + '';
$('#whatever').width(w);

Answer 2

You can override this as follows:

var w = /** @type {number} */ ($(window).width());
$('#whatever').width(w)