Intl.ResolvedDateTimeFormatOptions is missing properties

[BPScott]

lib Update Request

Configuration Check

My compilation target is ES2020 and my lib is the default.

Missing / Incorrect Definition

Intl.ResolvedDateTimeFormatOptions - the type returned by calling DateTimeFormat's resolvedOptions method - appears to be missing the following properties:

• dateStyle
• timeStyle
• dayPeriod
• hourCycle
• fractionalSecondDigits

It looks like these items (along with calendar and numberingSystem) were added to es2020.intl.d.ts's DateTimeFormatOptions however they were never added to ResolvedDateTimeFormatOptions.

It seems that calendar and numberingSystem are both present in es5.d.ts's ResolvedDateTimeFormatOptions. Because of this I am unsure if the absent options should be added to ResolvedDateTimeFormatOptions in es5.d.ts or es2020.d.ts.

https://tc39.es/ecma402/#table-datetimeformat-resolvedoptions-properties is the spec table of possible returned properties

Sample Code

Sample TS playground

console.log(new Intl.DateTimeFormat('en-US', { dateStyle: 'short' }).resolvedOptions().dateStyle)
console.log(new Intl.DateTimeFormat('en-US', { timeStyle: 'long' }).resolvedOptions().timeStyle)

console.log(new Intl.DateTimeFormat('en-US', { dayPeriod: 'narrow' }).resolvedOptions().dayPeriod)
console.log(new Intl.DateTimeFormat('en-US', { timeStyle: 'long', hourCycle:'h24' }).resolvedOptions().hourCycle)

console.log(new Intl.DateTimeFormat('en-US', { fractionalSecondDigits: 1 }).resolvedOptions().fractionalSecondDigits)

The above lines throw type errors saying the various properies on resolvedOptions do not exist

Documentation Link

https://tc39.es/ecma402/#table-datetimeformat-resolvedoptions-properties

[IllusionMH]

Duplicate of #42577 which itself is duplicate of other issues.
Not a duplicate of linked issue

[BPScott]

This issue looks to be more thorough than #42577 - which does not mention the dayPeriod or fractionalSecondDigits.

#42577 has been marked as a duplicate of #35865 / #34399. In both cases that appears to be an incorrect diagnosis, as both of those issues are about improvements to DateTimeFormatOptions, NOT ResolvedDateTimeFormatOptions.

• Missing specific types in DateTimeFormatOptions #35865 talks about strictening the types on DateTimeFormatOptions, changing them from string to specific values. This issue has been fixed as of TS 4.2 as that interface now uses unions of strings for those values.
• hourCycle option not recognized for Date.toLocaleString #34399 talks about an omission of hourCycle from DateTimeFormatOptions. This issue has been fixed as of TS 4.2 when targeting es2020 per this interface.

[IllusionMH]

Yes, you are correct. Read by diagonal and missed that ResolvedDateTimeFormatOptions were not updated to match other options added to options.

Also looks like it's tricky question in which file definitions should go as #42945 tries to "move" (in that case just removing) some of this properties of DateTimeFormatOptions to further versions.

[orta]

I'm reasonably sure I've got all these covered and merged into main with in #45647 - should be available in 4.5

[BPScott]

Heya @orta,

I'm not sure if I'm reading that PR correctly but it looks like DateTimeFormatOptions was updated but I can't see any adjustments to ResolvedDateTimeFormatOptions, or any places where the return interface of resolvedOptions() got changed to something else.

[BPScott]

Ping @orta, I've just tried on the nightly build playground and it still raises type errors.

I don't think this issue has been resolved as the types of ResolvedDateTimeFormatOptions don't seem to have been updated

[orta]

Yep, I agree 👍🏻

[BPScott]

Thanks @orta <3