URL setters test

[rubys]

tl;dr: http://intertwingly.net/projects/pegurl/url-setters.html

Longer version: I don't notice any URL setters tests in http://w3c.github.io/test-results/url/all.html

I've been developing some as a part of my reference implementation work: https://github.com/rubys/url/blob/peg.js/reference-implementation/test/urlsettest.yml

I believe that some form of this belongs in web-platform-tests.

I'm interested in any and all feedback, including but not limited to:

• what changes should be made to fit in with web-platform-tests
• identification of tests that don't match the spec
• changes needed to the spec to match deployed reality
• suggestions for additional tests. Note the TODOs at the top of the YAML file for items I already plan to get to.

@annevk @sideshowbarker @jgraham

[annevk]

href has a different codepath for URL objects vs <a>.

If you want to use JSON you need to use a list, as object order is not defined and we do not want indeterminate results.

Per specification # is escaped for passwords.

I recommend testing the delimiters. All the things where the normal parser would branch. E.g. when setting pathname, you want to test things like ../, ..?x, ..#x, x#, etc. (Now I take a closer look I see you've done some of that already for other properties, great.)

It would also be good to test unknown schemes here I guess. As per mailing list discussion the way they work needs to change and that will impact these algorithms. Although maybe you want to wait until we have an actual plan in place.

[annevk]

This got fixed by #2830.