Bug 190506 – Style attribute is created when an invalid property value is set via CSSOM

• Status: RESOLVED
• Resolution: WORKSFORME
• Component: CSS

[Emilio Cobos Álvarez (:emilio)]

let element = document.createElement("div");
element.style.width = "somethingthatisclearlynotawidth";
console.log(element.hasAttribute("style")); // logs true, should log false.

From https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-setproperty:

> 5. Let component value list be the result of parsing value for property property.
> 6. If component value list is null, then return.
> [...]
> 10. If updated is true, update style attribute for the CSS declaration block. 
 
Edge's behavior is correct, I'm changing Firefox in https://bugzilla.mozilla.org/show_bug.cgi?id=1498445, where I'm adding a few tests.

[Emilio Cobos Álvarez (:emilio)]

Err, actually WebKit is right as well, so never mind me.