types: optimise ParseTReturn by reading count and incremental options

[marcalexiei]

I have used the ParseKeys type to do define some keys that are then passed to a t function and I noticed that when there are a lot of keys typescript was really slow (similar to #2070).

Looking at the types it looks like the bottleneck was ParseTReturnPlural.

To reduce build time I added the TOpt as a new type parameter so all plural and ordinal keys can be computed only when the relative option is provided to the t function. According to this ParseTReturnPlural has been divided into two separate types:

• ParseTReturnPlural
• ParseTReturnPluralOrdinal

Each one provide they key for the relevant plural scenario

https://github.com/marcalexiei/i18next/blob/70f498d128ccfdf10a3848981eae05ca548daed5/typescript/t.d.ts#L157-L169

type ParseTReturn<
  Key,
  Res,
  TOpt extends TOptions = {},
> = Key extends `${infer K1}${_KeySeparator}${infer RestKey}`
  ? ParseTReturn<RestKey, Res[K1 & keyof Res], TOpt>
  : // Process plurals only if count is provided inside options
  TOpt['count'] extends number
  ? TOpt['ordinal'] extends boolean
    ? ParseTReturnPluralOrdinal<Res, Key>
    : ParseTReturnPlural<Res, Key>
  : // otherwise access plain key without adding plural and ordinal suffixes
    Res[Key & keyof Res];

Results

running tic inside the the many-keys typescript test scenario produced the following results:

Build time was done by ~40%.

In a more simple test scenario like the one of test:typescript:customtypes the build time was improved by 5/10%

Test machine is a MacBook Pro (15-inch, 2016).

Support JSONFormat v3 in typescript

I added a new test scenario for typescript where JSONFormat v3 (which is the custom-types scenario with few key change for plural and ordinal keys).

Checklist

• only relevant code is changed (make a diff before you submit the PR)
• run tests npm run test
• tests are included
• commit message and code follows the Developer's Certification of Origin

[coveralls]

coverage: 92.045%. remained the same
when pulling 70f498d on marcalexiei:feature/parse-t-return-perf
into 8ae4599 on i18next:master.

[adrai]

wow, this is awesome thank you very much...
Did you test it also with TS v4.x ?

[adrai]

Did you test it also with TS v4.x ?

I just tested it myself... looks good.
released with v23.7.13

Grazie Marco ;-)

[marcalexiei]

Sorry I was opening #2096 😅

Thank you for testing the change with TS 4.x!