Hello, we are implementing a breaking change to Chromium's import attributes implementation.
The import attributes proposal (https://tc39.es/proposal-import-attributes/, previously known as "import assertions") was recently updated to throw on unknown attribute keys, rather than ignoring them. Currently the only valid attribute is "type", defined by the HTML specification (for JSON and CSS imports) and by https://tc39.es/proposal-json-modules/. The previous version of this proposal has been implemented in Chromium for two years, and we are now updating to the new semantics. While this is technically a breaking change, the compatibility risk is very low: - The upper bound of import attributes usage is https://chromestatus.com/metrics/feature/timeline/popularity/4528. - None of the top websites listed in the link above uses unknown attributes. - No tool implemented attributes other than "type" (other than TypeScript's "resolution-mode", which is only valid when using the TS-specific import type syntax), so it's unlikely that somebody is shipping unknown attributes thinking that they are being compiled away by some tool. - A typo in type would already result in an error, since type is only used for CSS&JSON imports and it's mandatory. - Of the 9.6k results on GitHub for import assertions usage ( /import.*assert\s*\{/ <https://github.com/search?q=+language%3AJavaScript+%2Fimport.*assert%5Cs*%5C%7B%2F&type=code>), only 4 Node.js projects use an unknown "integrity" one (found by manually analyzing the results for /import.*assert\s*\{.*[^\s"'type].*:.*\}/ <https://github.com/search?q=+language%3AJavaScript+%2Fimport.*assert%5Cs*%5C%7B.*%5B%5E%5Cs%22%27type%5D.*%3A.*%5C%7D%2F&type=code>). Most of the results with unknown attributes are tests for various parsers or implementations. As such, this change is safe to ship. You can find the ChromeStatus entry at https://chromestatus.com/feature/5123137502445568. Thanks, Nicolò Ribaudo -- 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/192d117b-b2b9-4835-a6bd-bf5e49b64757n%40chromium.org.
