Thanks for doing a thorough compat analysis of this Mathias. I can totally see this being one where all the examples we can find don't seem to cause breakage in practice. I know it's a lot, but if we looked at 40 random examples and found none of them to break, that would suggest an upper bound of <0.001% of pages impacted (probably much lower) and I'd be OK giving this a shot with a finch killswitch ready in case of reports of serious breakage. Does that sound reasonable to you?
Also feel free to set your flag <https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/runtime_enabled_features.json5;l=1912?q=HTMLPatternRegExpUnicodeSets%20file:.json5&ss=chromium> to status=experimental, that'll get us some additional usage coverage (from the small population that runs with --enable-experimental-web-platform-features) and also signal that this is close to becoming shipping behavior. Rick On Mon, Apr 17, 2023 at 7:03 AM 'Mathias Bynens' via blink-dev < blink-dev@chromium.org> wrote: > So far, none of the UseCounter hits I investigated constitute any actual > breakage. The vast majority of hits seem to be login forms backed by > server-side validation. I’ll keep looking though. > > In the meantime, this feature is now > <https://chromium-review.googlesource.com/c/chromium/src/+/4414859> > available behind the `--enable-blink-features=HTMLPatternRegExpUnicodeSets` > flag (disabled by default). > > On Wednesday, April 5, 2023 at 5:53:10 PM UTC+2 Mathias Bynens wrote: > >> On Wed, Apr 5, 2023 at 5:23 PM Alex Russell <sligh...@chromium.org> >> wrote: >> >>> I don't understand why TAG review is not applicable for this intent. >>> >> >> Fair enough. I’ve filed a TAG review request here: >> https://github.com/w3ctag/design-reviews/issues/832 I’ll update the >> ChromeStatus entry to refer to it. >> >> On Tuesday, April 4, 2023 at 5:21:16 AM UTC-7 mt...@google.com wrote: >>> >> Thanks to the UseCounter + UKM + M112 hitting Stable, more results are >>>> starting to come in. I’ll be collecting public examples of potential >>>> incompatibilities here: >>>> https://bugs.chromium.org/p/chromium/issues/detail?id=1412729#c11 So >>>> far 0 out of the 2 examples cause any actual breakage — fingers crossed >>>> that trend continues. >>>> >>>> On Mon, Apr 3, 2023 at 10:26 AM Philip Jägenstedt <foo...@chromium.org> >>>> wrote: >>>> >>> I took a look at https://github.com/whatwg/html/pull/7908 and it looks >>>>> like there's agreement to merge it, but it's waiting on this intent to be >>>>> approved. Normally we block in the other direction, but that's fine, as >>>>> long as the spec change is merged. >>>>> >>>>> Looks like there's broad support for this change, and it's just a >>>>> question of the site compat risk. ~0.04% as an upper bound is quite high. >>>>> Can we wait until the use counter is in stable and look at a random set of >>>>> sites hitting the use counter to determine what the real-world breakage >>>>> looks like? >>>>> >>>>> On Fri, Mar 31, 2023 at 5:07 PM 'Mathias Bynens' via blink-dev < >>>>> blin...@chromium.org> wrote: >>>>> >>>> On Fri, Mar 31, 2023 at 4:35 PM Mike Taylor <mike...@chromium.org> >>>>>> wrote: >>>>>> >>>>>>> Hey Mathias, >>>>>>> On 3/31/23 5:56 AM, Mathias Bynens wrote: >>>>>>> >>>>>>> Contact emails >>>>>>> >>>>>>> mat...@chromium.org >>>>>>> >>>>>>> Specification >>>>>>> >>>>>>> https://github.com/whatwg/html/pull/7908 >>>>>>> >>>>>>> Summary >>>>>>> >>>>>>> The <input pattern> attribute allows developers to specify a >>>>>>> regular expression pattern against which the input’s values are checked >>>>>>> for >>>>>>> validity. >>>>>>> >>>>>>> <label> >>>>>>> >>>>>>> Part number: >>>>>>> >>>>>>> <input pattern="[0-9][A-Z]{3}" name="part" >>>>>>> >>>>>>> title="A part number is a digit followed by three >>>>>>> uppercase letters."> >>>>>>> >>>>>>> </label> >>>>>>> >>>>>>> When the pattern attribute was first implemented, these regular >>>>>>> expressions were compiled without any RegExp flags. In 2014, the HTML >>>>>>> Standard changed this by implicitly enabling the u flag for the >>>>>>> pattern attribute, enabling better Unicode support (including support >>>>>>> for >>>>>>> Unicode character properties like \p{Letter}). This change shipped >>>>>>> in Chrome 53. <https://chromestatus.com/feature/4753420745441280> >>>>>>> >>>>>>> Now, we’re taking this to the next level by enabling the new RegExp >>>>>>> v flag <https://v8.dev/features/regexp-v-flag> instead of u, >>>>>>> enabling the use of set notation, string literal syntax, and Unicode >>>>>>> properties of strings. >>>>>>> >>>>>>> (Context: The RegExp v flag is a JavaScript language feature which >>>>>>> previously went through the Blink Intents process and shipped in >>>>>>> Chrome 112 <https://chromestatus.com/feature/5144156542861312>. >>>>>>> This new ChromeStatus entry is specifically about integrating it with >>>>>>> the >>>>>>> HTML pattern attribute.) >>>>>>> >>>>>>> Blink component >>>>>>> >>>>>>> Blink>Forms >>>>>>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EForms> >>>>>>> >>>>>>> Search tags >>>>>>> >>>>>>> unicode <https://chromestatus.com/features#tags:unicode>, regexp >>>>>>> <https://chromestatus.com/features#tags:regexp>, pattern >>>>>>> <https://chromestatus.com/features#tags:pattern>, validation >>>>>>> <https://chromestatus.com/features#tags:validation> >>>>>>> >>>>>>> TAG review >>>>>>> TAG review status >>>>>>> >>>>>>> Not applicable >>>>>>> >>>>>>> Risks >>>>>>> Interoperability and Compatibility >>>>>>> >>>>>>> The spec patch at https://github.com/whatwg/html/pull/7908 lists >>>>>>> the potentially breaking changes. Some patterns that previously would >>>>>>> compile, now throw an early error with the v flag — specifically >>>>>>> those with a character class including either an unescaped special >>>>>>> character or a double punctuator. >>>>>>> >>>>>>> We expect such patterns to be rare. To validate this assumption >>>>>>> we’ve added a UseCounter called >>>>>>> HTMLPatternRegExpUnicodeSetIncompatibilitiesWithUnicodeMode >>>>>>> <https://chromestatus.com/metrics/feature/popularity#HTMLPatternRegExpUnicodeSetIncompatibilitiesWithUnicodeMode> >>>>>>> in M112, which tracks patterns in any JavaScript u RegExps >>>>>>> generated via the HTML pattern attribute that would throw if they >>>>>>> were used with the v flag. >>>>>>> >>>>>>> Importantly, note that any throwing pattern gracefully degrades — it >>>>>>> simply behaves as if the pattern attribute wasn’t present, >>>>>>> resulting in inputElement.validity.valid === true for any input >>>>>>> value. Consequently, the only compatibility risk is that some >>>>>>> value/pattern >>>>>>> combinations that would previously result in >>>>>>> inputElement.validity.valid being false now result in it being true. >>>>>>> Thus, for every UseCounter hit, it could still be that there is no >>>>>>> actual breakage — the UseCounter just gives us the upper bound. The >>>>>>> currently available data from Beta suggests the UseCounter hits for >>>>>>> 0.0393% of Chrome page loads. >>>>>>> >>>>>>> I'm somewhat curious to see how much that UseCounter will grow (if >>>>>>> at all) when 112 goes to stable next week... >>>>>>> >>>>>> Me too, and FWIW I'd understand if you and the other API owners >>>>>> prefer to wait until there’s some data for Stable before responding to >>>>>> this >>>>>> Intent. >>>>>> >>>>>>> Do you have any concerns about certain inputs being sent to a server >>>>>>> that might not have any backend validation, that would previously be >>>>>>> prevented by the u-vintage validation? >>>>>>> >>>>>> That’s indeed the only scenario in which there would be breakage. So >>>>>> far we haven’t heard of such cases in the wild. (Arguably, such web pages >>>>>> are already broken, since DevTools could easily be used to remove the >>>>>> `pattern` attribute, or requests could be made with tools like `curl`.) >>>>>> FWIW, there was a similar discussion in this old blink-dev thread: >>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/XUNMtri0tI4/m/mjPkwXKNAQAJ >>>>>> >>>>>> I forgot to mention that we explicitly added a console warning in >>>>>> M112 for any `pattern` attribute values that would be affected by this >>>>>> change, to help developers prepare for the potential change. One >>>>>> developer >>>>>> reported seeing the warning and adjusting their `pattern` attribute >>>>>> values >>>>>> accordingly, but it’s unclear whether inaction would have really broken >>>>>> their web page: >>>>>> https://bugs.chromium.org/p/chromium/issues/detail?id=1412729#c7 >>>>>> >>>>>> >>>>> >>>>>>> Gecko: Positive (Mozilla standards position request >>>>>>> <https://github.com/mozilla/standards-positions/issues/745>, >>>>>>> implementation >>>>>>> tracking issue >>>>>>> <https://bugzilla.mozilla.org/show_bug.cgi?id=pattern-v>) >>>>>>> >>>>>>> WebKit: Positive (WebKit standards position request >>>>>>> <https://github.com/WebKit/standards-positions/issues/132>, >>>>>>> implementation >>>>>>> tracking issue <https://bugs.webkit.org/show_bug.cgi?id=pattern-v>) >>>>>>> >>>>>>> Web developers: No signals >>>>>>> >>>>>>> Other signals: >>>>>>> >>>>>>> Debuggability >>>>>>> >>>>>>> The pattern attribute is already well-supported in DevTools and >>>>>>> other tooling; no changes are necessary. >>>>>>> >>>>>>> Will this feature be supported on all six Blink platforms (Windows, >>>>>>> Mac, Linux, Chrome OS, Android, and Android WebView)? >>>>>>> >>>>>>> Yes >>>>>>> >>>>>>> Is this feature fully tested by web-platform-tests >>>>>>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> >>>>>>> ? >>>>>>> >>>>>>> Pull Request: https://github.com/web-platform-tests/wpt/pull/38547 >>>>>>> >>>>>>> Flag name >>>>>>> >>>>>>> N/A >>>>>>> >>>>>>> Requires code in //chrome? >>>>>>> >>>>>>> False >>>>>>> >>>>>>> Tracking bug >>>>>>> >>>>>>> https://bugs.chromium.org/p/chromium/issues/detail?id=1412729 >>>>>>> >>>>>>> Sample links >>>>>>> >>>>>>> https://mathiasbynens.be/demo/pattern-u-vs-v >>>>>>> >>>>>>> Estimated milestones >>>>>>> >>>>>>> M114 >>>>>>> >>>>>>> Link to entry on the Chrome Platform Status >>>>>>> >>>>>>> https://chromestatus.com/feature/5149507107422208 >>>>>>> >>>>>>> -- >>>>>>> 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 blink-dev+...@chromium.org. >>>>>>> >>>>>>> >>>>>>> To view this discussion on the web visit >>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADizRgaAq4FwzJbUqLQVo%2BQdd_V0PT7rBr510OGe8fenHA%3D3HQ%40mail.gmail.com >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADizRgaAq4FwzJbUqLQVo%2BQdd_V0PT7rBr510OGe8fenHA%3D3HQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>>> -- >>>>>>> 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 blink-dev+...@chromium.org. >>>>>> >>>>>> >>>>>>> To view this discussion on the web visit >>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/c9571b2a-a35b-3824-0f37-c93a9bb522fc%40chromium.org >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/c9571b2a-a35b-3824-0f37-c93a9bb522fc%40chromium.org?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>> -- >>>>>> 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 blink-dev+...@chromium.org. >>>>> >>>>> >>>>>> To view this discussion on the web visit >>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADizRgYxU2v2ANQgzNiLD%2B4P-qJHxzTYJfRDsKNCtY0Yb_0bdg%40mail.gmail.com >>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADizRgYxU2v2ANQgzNiLD%2B4P-qJHxzTYJfRDsKNCtY0Yb_0bdg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>> . >>>>>> >>>>> -- > 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 blink-dev+unsubscr...@chromium.org. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/bf73fe5b-fde2-42df-90f0-582a905d1948n%40chromium.org > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/bf73fe5b-fde2-42df-90f0-582a905d1948n%40chromium.org?utm_medium=email&utm_source=footer> > . > -- 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 blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY-FwDRdht7trHyNzbt%3DMVmmaVE0oj4h9Xoe2O4R9Axhhw%40mail.gmail.com.
