Web Inspector: Fix the debounce function

[Timothy Hatcher]

It puts the symbol on the bound function, not the original.

[Radar WebKit Bug Importer]

<rdar://problem/25778133>

[Timothy Hatcher]

Created attachment 276638 [details]
Patch

[BJ Burg]

Comment on attachment 276638 [details]
Patch

r=me

Could you include a short description of how to use this function? I had to go over to underscore.js to confirm what I thought was going on.

[Timothy Hatcher]

https://trac.webkit.org/changeset/199676

[Joseph Pecoraro]

Comment on attachment 276638 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=276638&action=review

> Source/WebInspectorUI/UserInterface/Base/Utilities.js:1210
> -            let callback = this.bind(thisObject);
> -            return function() {
> -                clearTimeout(callback[debounceSymbol]);
> +            return () => {
> +                clearTimeout(this[debounceSymbol]);
> +
>                  let args = arguments;
> -                callback[debounceSymbol] = setTimeout(() => {
> -                    callback.apply(null, args);
> +                this[debounceSymbol] = setTimeout(() => {
> +                    this.apply(thisObject, args);
>                  }, delay);
>              };

I don't think this works. Because the "arguments" here are not the correct arguments.

Looking back at the original bug:
https://bugs.webkit.org/show_bug.cgi?id=152655

Maybe this can be reduced to:

    value: function(delay, thisObject)
    {
        return (...args) => {
            clearTimeout(this[debounceSymbol]);
            this[debounceSymbol] = setTimeout(this.bind(thisObject), delay, ...args);
        }
    }

We could add a unit-test for this.