Implement XMLHttpRequest.responseURL

[jdm]

We have a method that ostensibly implements the specification (XMLHttpRequest::ResponseURL), but we don't actually set the response_url member of XMLHttpRequest anywhere except the constructor. We should set this value appropriately inside process_partial_response in the XHRProgress::Done branch, and the member will need to be DOMRefCell<DOMString> (rather than a plain DOMString) to accommodate the new mutation.

Code: components/script/dom/xmlhttprequest.rs
Tests: ./mach test-wpt tests/wpt/web-platform-tests/XMLHttpRequest

[jackinloadup]

I'd like to try and take this task on

[KiChjang]

You got it!

[jdm]

Oh, I forgot to include the specification in the original description: https://xhr.spec.whatwg.org/#the-responseurl-attribute

[KiChjang]

@jackinloadup any updates on this?

[jackinloadup]

I have some code in place but I have been having some difficulty figuring out how to debug the internals of various values.

Namely how to use gdb or some other tool to inspect aspects of hyper headers or url fields.

jackinloadup@be1d04f

[jdm]

@jackinloadup There are rust-lldb and rust-gdb wrappers that include pretty-printers in .servo/rust/[hash]/rustc-1.0.0-[platform]/bin/ that can be run against the target/debug/servo binary.

[jdm]

I use regular lldb on OS X for the same purpose, via ./mach run --debug.

[KiChjang]

@jackinloadup still working on this issue?

[shinglyu]

May I give it a try?

[KiChjang]

Yes, absolutely!

[shinglyu]

I tried to write a wpt test to cover this. But I was unable to run the single test file.
STR:

• Use ./mach create-wpt tests/wpt/web-platform-tests/XMLHttpRequest/responseurl.htm
• Copy the responsexml-basic.htm test into responseurl.htm
• Run with ./mach test-wpt tests/wpt/web-platform-tests/XMLHttpRequest/responseurl.htm

Expected:
The test runs

Actual:
The test starts, opens a blak Servo window and hangs forever

Notes:
I tried ./mach test-wpt tests/wpt/web-platform-tests/XMLHttpRequest and it works, no Servo window poping up, and the test can catch errors if I add an assert(false) in it. But running a single file (I tried ./mach test-wpt tests/wpt/web-platform-tests/XMLHttpRequest/responsexml-basic.htm) it just doesn't run. What's the difference between running a single file and a folder?

[jdm]

That's very strange; that's supposed to work. Could you push your changes to a branch on github?