Implement URLSearchParams.prototype.sort()

[CYBAI]

---

• ./mach build -d does not report any errors
• ./mach test-tidy does not report any errors
• These changes fix #22545
• There are tests for these changes

---

This change is 

[highfive]

Heads up! This PR modifies the following files:

• @asajeffrey: components/script/dom/webidls/URLSearchParams.webidl, components/script/dom/urlsearchparams.rs
• @KiChjang: components/script/dom/webidls/URLSearchParams.webidl, components/script/dom/urlsearchparams.rs

[jdm]

r? @Manishearth
There's enough questions about counting and comparing unicode values here that it will be quicker for someone with more experience to review this.

[Manishearth]

Comments on the issue indicate they're thinking of the comparison algorithm in https://tc39.github.io/ecma262/#sec-abstract-relational-comparison , which is based on utf16 code units (not utf8)

This implementation can either:

• convert the list to utf16, sort, and convert back
• write a custom comparison function for strings that one at a time compares utf16 code units. this is tricky but doable, and is faster

[jdm]

I doubt the performance of URLSearchParams.sort is particularly important, so I lean towards doing the less tricky thing.

[CYBAI]

@jdm @Manishearth Thanks! I'll try to do the less tricky thing with comparing with encode_utf16!

[CYBAI]

@bors-servo try=wpt

• Updated! This is ready for review!

[bors-servo]

⌛ Trying commit f43c604 with merge dc39da9...

[bors-servo]

☀️ Test successful - linux-rel-css, linux-rel-wpt, status-taskcluster
State: approved= try=True

[nox]

I doubt the performance of URLSearchParams.sort is particularly important, so I lean towards doing the less tricky thing.

There is no need to be tricky, though. Just use the standard library.

a.chars().flat_map(char::decode_utf16).cmp(b.chars().flat_map(char::decode_utf16))

Edit: this should use flat_map not map.

[Manishearth]

That won't work, decode_utf16 doesn't return an iterator, and doesn't live long enough to be converted into a flat-mappable iterator

[CYBAI]

Ah, maybe I should share the discussion with @nox on IRC earlier.
@nox just said he wrote the comment in a wrong way and he also asked me to disregard his comment.

So I think this PR is ready for review ?

Ref: https://mozilla.logbot.info/servo/20190108#c15803031

cc @Manishearth

[nox]

Yes it is, and the code is correct.

@bors-servo r+

[bors-servo]

📌 Commit f43c604 has been approved by nox

[bors-servo]

⌛ Testing commit f43c604 with merge 2cd2bd8...

[bors-servo]

💔 Test failed - mac-rel-css1

[CYBAI]

@bors-servo retry

{
    "status": "TIMEOUT", 
    "group": "default", 
    "message": null, 
    "stack": null, 
    "subtest": null, 
    "test": "/_mozilla/mozilla/referrer-policy/no-referrer/meta-csp/cross-origin/http-http/link-tag/generic.keep-origin-redirect.http.html", 
    "line": 59369, 
    "action": "test_result", 
    "expected": "OK"
}

[bors-servo]

⌛ Testing commit f43c604 with merge fda1f9e...

[bors-servo]

💔 Test failed - mac-rel-css1

[jdm]

@bors-servo retry

• #22661

[bors-servo]

💣 Failed to start rebuilding: Unknown error

[bors-servo]

⌛ Testing commit f43c604 with merge f6610ee...

[bors-servo]

💔 Test failed - mac-rel-css1

[jdm]

@bors-servo retry

[bors-servo]

⚡ Previous build results for android-mac, arm32, arm64, linux-rel-css, linux-rel-wpt, mac-rel-css2, mac-rel-wpt1, mac-rel-wpt2, mac-rel-wpt3, mac-rel-wpt4, magicleap, status-taskcluster are reusable. Rebuilding only mac-rel-css1...

[bors-servo]

💔 Test failed - mac-rel-css1

[CYBAI]

@bors-servo retry

[bors-servo]

⌛ Testing commit f43c604 with merge 2e15cf0...

[bors-servo]

☀️ Test successful - android-mac, arm32, arm64, linux-rel-css, linux-rel-wpt, mac-rel-css1, mac-rel-css2, mac-rel-wpt1, mac-rel-wpt2, mac-rel-wpt3, mac-rel-wpt4, magicleap, status-taskcluster
Approved by: nox
Pushing 2e15cf0 to master...