`Duration.from` doesn't reject some invalid strings

[fabon-f]

Temporal.Duration.from('P05DT')

This code throws RangeError in Firefox Nightly, @js-temporal/polyfill and reference polyfill, but returns duration with 5 days in temporal-polyfill.

According to the spec, TimeDesignator should be followed by DurationHoursPart, DurationMinutesPart or DurationSecondsPart. Thus this polyfill is probably not spec-compliant.

https://tc39.es/proposal-temporal/#prod-DurationTime

note: it seems that test262 doesn't cover this invalid case.

https://github.com/tc39/test262/blob/main/test/built-ins/Temporal/Duration/from/argument-string-invalid.js

[arshaw]

Thanks @fabon-f, I'll ensure temporal-polyfill follows this behavior. I'll also submit an improved test to tc39