Timezone support broken in Vite due to dynamic require of date-fns-tz

[PurkkaKoodari]

Describe the bug
When developing with Vite with the default React config, the new timeZone prop fails to work.

This seems to be due to the code dynamically using require to import date-fns-tz, which apparently isn't supported by Vite:

react-datepicker/src/date_utils.ts

Lines 118 to 120 in 644f2f5

	const dateFnsTzModuleName = "date-fns-tz";
	// eslint-disable-next-line @typescript-eslint/no-require-imports
	dateFnsTz = require(dateFnsTzModuleName) as DateFnsTz;

Screenshot from debugger, inside the require call in the above code.

To Reproduce
Steps to reproduce the behavior:

1. See the minimal Vite setup in https://codesandbox.io/p/devbox/fmvlts (use https://fmvlts-5173.csb.app/ to view outside the editor)
2. Observe times are rendered in local time
3. Observe the timeZone prop requires "date-fns-tz" package warning in console

Expected behavior
Dates rendered in configured timeZone (Pacific/Auckland in example to make it clear).

If this requires specific configuration on the Vite side, it would be a good idea to document in timezone.md (but I couldn't find anything to enable dynamic require in Vite).

Screenshots
N/A

Desktop (please complete the following information):

• OS: Debian testing
• Browser: Firefox 147.0b9

[foobarrio]

Out of curiosity, why use date-fns-tz instead of @date-fns/tz?

[matys1]

This is a real issue. I have a React Router app that uses Vite and after installing the date-fns-tz package and using the timeZone prop I see this in console:

installHook.js:1 react-datepicker: timeZone prop requires "date-fns-tz" package. Please install it: npm install date-fns-tz

[huynhvequyen]

I'm having same warning in console:
react-datepicker: timeZone prop requires "date-fns-tz" package. Please install it: npm install date-fns-tz

And I'm using Webpack. May I ask if there's an workaround for this?

[Alexolo]

Seems that this is not the issue in 9.0.0, but appears in 9.1.0, at least on my setup.

Initially used 9.1, but downgraded to test and the warning disappeared.

I'm using Webpack aswell.

[afilp]

Is there a fix for this please?
@martijnrusschen Thanks a lot!