Implement and test DOMTokenList.replace (fixes #8511)

[nox]

Thanks to @sankha93 for the original work in #8525.

[nox]

This is a WIP: replace actually needs supports to be implemented.

[frewsxcv]

I know it's a WIP, but a couple suggestions if you weren't already going to do them:

1. explicitly add in the spec steps
2. create a separate internal function run_update_steps that performs the steps outlined here and link to that

[nox]

There is no run_update_steps because the associated attribute's value is actually the only storage for their list of tokens. We already do this.

[bors-servo]

☔ The latest upstream changes (presumably #9605) made this pull request unmergeable. Please resolve the merge conflicts.

[jdm]

@nox What's the status here? Is this still classified a WIP and needs more work, or should @asajeffrey be reviewing it?

[nox]

I'll look at it tonight or tomorrow while rebasing it.

[asajeffrey]

I've been holding off while it has conflicts, let me know when you're ready.

[nox]

@asajeffrey This is ok to go.

[asajeffrey]

Mostly this looks fine, there's a spec issue plus a couple of extra tests I think we should add, but otherwise cool

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Reviewed 4 of 4 files at r1.
Review status: all files reviewed at latest revision, 3 unresolved discussions.

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components/script/dom/domtokenlist.rs, line 135 [r1] (raw file):
It looks like this is slightly different from the spec in the case list.replace("a b", ""). The spec says it should throw a SyntaxError, it will actually throw an InvalidCharacterError.

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tests/wpt/web-platform-tests/dom/nodes/Element-classlist.html, line 84 [r1] (raw file):
Can we add tests:

assert_throws( 'SYNTAX_ERR', function () { elem.classList.replace('', 'a b'); }
assert_throws( 'SYNTAX_ERR', function () { elem.classList.replace('a b', ''); }

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tests/wpt/web-platform-tests/dom/nodes/Element-classlist.html, line 263 [r1] (raw file):
Can we add a test for the case where we're replacing a token with one that's already in the list:

  secondelem.className = 'token1 token2 token3'
  secondelem.classList.replace('token1', 'token3');
  assert_equals( secondelem.classList.length, 2 );
  assert_false( secondelem.classList.contains('token1') );
  assert_true( secondelem.classList.contains('token2') );
  assert_true( secondelem.classList.contains('token23') );

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Comments from the review on Reviewable.io

[jdm]

I think assert_throws(new SyntaxError(), function () { elem.classList.replace('', 'a b'); } is more idiomatic.

[Ms2ger]

That's an other kind of SyntaxError

[bors-servo]

☔ The latest upstream changes (presumably #9763) made this pull request unmergeable. Please resolve the merge conflicts.

[asajeffrey]

@nox: is this PR still open?

[nox]

It is still open, still blocked, still didn't address it, I'll try to do it soon.

[nox]

@asajeffrey Ready to go.

[asajeffrey]

Okay, I'll take a look later today.

[asajeffrey]

Reviewed 4 of 4 files at r2.
Review status: all files reviewed at latest revision, 4 unresolved discussions.

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components/script/dom/domtokenlist.rs, line 142 [r2] (raw file):
Can you add comments for how the code lines up with the steps of the spec?

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Comments from the review on Reviewable.io

[nox]

Done. r?

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Review status: 3 of 4 files reviewed at latest revision, 4 unresolved discussions.

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components/script/dom/domtokenlist.rs, line 135 [r1] (raw file):
Done.

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components/script/dom/domtokenlist.rs, line 142 [r2] (raw file):
Done.

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tests/wpt/web-platform-tests/dom/nodes/Element-classlist.html, line 84 [r1] (raw file):
Done.

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tests/wpt/web-platform-tests/dom/nodes/Element-classlist.html, line 263 [r1] (raw file):
Done.

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Comments from the review on Reviewable.io

[asajeffrey]

Reviewed 1 of 1 files at r3.
Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from the review on Reviewable.io

[asajeffrey]

@bors-servo r+

[bors-servo]

📌 Commit d010df9 has been approved by asajeffrey

[bors-servo]

⌛ Testing commit d010df9 with merge 59ba00e...

[bors-servo]

💔 Test failed - linux-rel

[asajeffrey]

@bors-servo retry

• #9724

[bors-servo]

⚡ Previous build results for android, arm32, gonk, linux-dev, mac-dev-unit, mac-rel-css, mac-rel-wpt, status-appveyor are reusable. Rebuilding only linux-rel...

[bors-servo]

☀️ Test successful - android, arm32, gonk, linux-dev, linux-rel, mac-dev-unit, mac-rel-css, mac-rel-wpt, status-appveyor