The spec issue [1] is resolved (for translate): RESOLVED: % values of translate are serialized as percent for computed values. Add note making the behavior explicit. So we can remove "GETCS_NEEDS_LAYOUT_FLUSH" from translate, I think, and serialize it by servo. The new wpt [2] was added for this. [1] https://github.com/w3c/csswg-drafts/issues/2124 [2] https://searchfox.org/mozilla-central/rev/b096dcf0ea226af628fe03f7e7acb56a25853533/testing/web-platform/tests/css/css-transforms/parsing/translate-parsing-valid.html#26

There are still some spec issues, so we don't pass the wpt which related to calc on translate. I address the issue links there.

Pushed by boris.chiou@gmail.com: https://hg.mozilla.org/integration/autoland/rev/14e4e5920241 Percentage values of translate are serialized as percent for computed values. r=emilio

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/14010 for changes under testing/web-platform/tests

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Upstream PR merged

css/css-transforms/transforms-support-calc.html assert_equals(getComputedStyle(target).translate, 'calc(20% + 30px) calc(100% - 200px)'); Why not assert_equals(getComputedStyle(target).translate, 'calc(20% + 30px) calc(100% + -200px)'); https://drafts.csswg.org/css-values/#math-function-serialize-a-summation Serialize all the terms, then join them into a single string, with " + " between each term.

I updated the testcase according to this spec issue: https://github.com/w3c/csswg-drafts/issues/1731 Maybe it's worth to file a proposal or new issue for the definition of "join" in the spec.

OK, I have filed https://github.com/w3c/csswg-drafts/issues/3335