Implement HTMLScriptElement.src

[jdm]

Needed for #841.

[jdm]

For the person (kangz) on IRC who was asking about writing tests - ignore src/test/html, and write tests in src/test/html/content instead.

[marcoscaceres]

Is there some kind of contributor guide for this project? It would be good to clarify the testing story there and put something slightly more concrete in place. I say this because I also was not sure what kind of test was expected with a PR.

[jdm]

@marcoscaceres There's https://github.com/mozilla/servo/wiki/Contributing. We could probably expand on it, too.

[marcoscaceres]

Filed a bug about contributing (happy to help with that) #1026

[ibnc]

Just looking for some clarification on this bug... I'm assuming that a request needs to be made to the url provided, and then the javascript needs to be evaluated. Or is it just as simple as setting the src attribute in HTMLScriptElement?

[Ms2ger]

For #841, what's needed is that script.src returns the resolved* value of the src content attribute. The setter isn't required there. (Though the actual script loading trigger should be in whatever we do for AfterSetAttr, or something.)

[*] might not even need to be resolved, actually.

[ibnc]

Okay I think I understand, but just to make sure HTMLScriptElement.src should return the value set in the src parameter of the script tag.

[tetsuharuohzeki]

We haven't implemented the setter yet. I think we should keep open this, or file the new issue about it.

[jdm]

We'll file a new one, because it's significantly more complicated than the getter, and we only need the getter for #841.

[tetsuharuohzeki]

OK. I filed #1113.