fix(ios): internal picker state persisting with recycling

[sterlingwes]

Summary

Follow-up to the min/max constraint fix in #1009. There was a pre-existing issue when the component gets unmounted: the native component gets recycled for future reuse but keeps its picker instance properties along with their state.

This likely would have also fixed the earlier issue but I think those changes are worth keeping as they make it clearer how the UIDatePicker constraints operate.

Test Plan

Video showing the crash case:

pickerbug.mp4

Two breakpoints here:

• one in the recycle lifecycle method to show that the picker retains constraints
• one right before we apply props for the next picker to show that the constraints are stale before the crash

Video showing the fix:

pickerbugfixed.mp4

Breakpoints show that the min/max date constraints are cleared

What's required for testing (prerequisites)?

I copied over this component from the reproduction app (provided by @Junveloper in the prior PR). You can reference this branch for the changes required: sterlingwes#1

What are the steps to reproduce (after prerequisites)?

• open the modal
  • pick two dates in the next month
  • submit / close modal
• open modal again
  • tap to pick first date and it should crash

Compatibility

OS	Implemented
iOS	✅
Android	❌

Checklist

• I have tested this on a simulator
• I added the documentation in README.md
• I updated the typed files (TS and Flow)
• I added a sample use of the API in the example project (example/App.js)
• I have added automated tests, either in JS or e2e tests, as applicable

[sterlingwes]

can't set this to nil - this appears to be the default when you instantiate a UIDatePicker

[Junveloper]

Thank you for this @sterlingwes , can't wait for this to be merged! :)

[vonovak]

thanks for the PR. Could this be resolved by disabling recycling altogether? The benefit for date pickers is minimal and there's a lot of internal state that could mess things up.

see https://blog.swmansion.com/react-natives-new-architecture-the-tricky-parts-1-2-bb0c16950f2d

+ (BOOL)shouldBeRecycled
{
  return NO;
}

[sterlingwes]

yup good call @vonovak , simpler is better here for sure

did the same before / after test and can confirm this fixes as shown above

[Junveloper]

Thank you @vonovak and @sterlingwes . When could I expect a new release? :)

[sterlingwes]

@Junveloper momentarily - when this MR lands: #1027

Thanks for sharing the reproduction case! And to vonovak for the quick review 🙏🏻

[Junveloper]

Thank you, you guys are legends!