On Thu, Sep 18, 2025 at 2:51 PM Mike Taylor <[email protected]> wrote:
> On 9/18/25 5:54 a.m., Philip Jägenstedt wrote: > > Some additional context. Upgrading ICU can break sites and it cannot be > done with a flag because of the size of the library (two copies would be > needed). To mitigate the risk, we'd like to use the Blink launch process > going forward. Where we can identify a risk ahead of time, we can add a > targeted flag for that, as we've done for Italian number formatting here. > > On Thu, Sep 18, 2025 at 11:40 AM Chromestatus < > [email protected]> wrote: > >> *Contact emails* >> [email protected], [email protected] >> >> *Explainer* >> None >> >> *Specification* >> https://tc39.es/ecma402 >> >> *Design docs* >> >> https://unicode-org.github.io/icu/download/77.html >> https://cldr.unicode.org/downloads/cldr-46 >> https://www.unicode.org/versions/Unicode16.0.0 >> >> *Summary* >> ICU is not a feature itself, but the third-party library we use for >> general Unicode support. We are using the Blink launch process because >> there is web compat risk and security considerations. The upgrade is from >> ICU 74.2 to ICU 77.1, the current latest release. ICU 77 contains CLDR 46 >> and other changes to support Unicode 16. The web-exposed changes are mainly >> the Intl and RegExp APIs, IDNA rules for URLs, and text segmentation. Intl >> and RegExp (V8): Lots of small changes. The change of Italian number >> formatting is the riskiest and has a dedicated flag, see compat risk >> section. IDNA: Generally more things are allowed, and this upgrade improves >> our overall test results in WPT. Text segmentation: The most interesting >> change is better Japanese line breaking when using `word-break: >> auto-phrase`, related to >> https://chromestatus.com/feature/5133892532568064. All test changes are >> explained in >> https://docs.google.com/document/d/1lrfJJmWvLXYPYSYlxE3mXTgDZI9U1bw2FrJYrDorgqE/edit?usp=sharing > > This doc mentions changes to "added comma in en-GB in a date format" - > where's the best place to see what that change looks like? This kind of > change sounds pretty similar to > https://issues.chromium.org/issues/40256057 (or go/omg-1414292-pm if you > can read it (apologies to non-googlers)), and the type of things to easily > break regular expressions > It shows up in two places in test changes in https://chromium-review.googlesource.com/c/chromium/src/+/6578333. The first is base/i18n/time_formatting_unittest.cc with these are the changes: "Saturday 30 April 2011 at 15:42:07" → "Saturday, 30 April 2011 at 15:42:07 "Saturday 30 April 2011" → "Saturday, 30 April 2011" The other is third_party/blink/web_tests/webexposed/intl-date-time-format-expected.txt with this change: "Wednesday 14 June 2023 at 14:50:00 British Summer Time" → "Wednesday, 14 June 2023 at 14:50:00 British Summer Time" I agree that this carries some risk. On the "probably fine" part of the ledger we have: - It aligns more with en-US where there is a comma for the "full" format, as well as some of the shorter ones - Firefox shipped it and didn't get any regression reports about this. I can't spot anything in my own search <https://bugzilla.mozilla.org/buglist.cgi?query_format=specific&order=relevance+desc&bug_status=__all__&product=&content=en-gb+comma&comments=0> either. https://issues.chromium.org/issues/40256057 is precisely the reason why nobody has updated ICU for a long time and why it's important to have enough checks in place to make such breakage much less likely. Putting a change like this behind a flag is a bit fraught because we're writing some new code to emulate what older versions of ICU did, and can't be 100% confident that it's correct for all combinations. I will dig up the CLDR change behind this and see if it's controllable by ICU inputs, as was luckily the case for the Italian number formatting change. Best regards, Philip -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAARdPYeROv_-OoFLZ_x7Kqhn2FJW003onb_asyQy%2Bs0kJvPVng%40mail.gmail.com.
