Add IColChooserModel cross-platform interface

[amcclain]

…form typing

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[ghsolomon]

This definitely seems like an improvement and agree that the cross-platform type imports should be erased. I think I would prefer a shared ColChooserModel interface that the 2 platform-specific classes implement over the union type in this case for a couple reasons:

• With a single shared interface, there would be one place for developers to look as opposed to the union type which requires looking at the 2 implementations to determine what is shared.
• Along similar lines, for our own development, the single shared interface gives us a clean contract across both of our platform-specific implementations as opposed to the other way around.

It would add complexity, but would we want this to be generic? I can't really think of a way to infer the desktop vs mobile type -- would likely need to be specified explicitly, so that might not really be any better than a cast.

[amcclain]

@ghsolomon updated - WDYT? Improvement?

[ghsolomon]

@ghsolomon updated - WDYT? Improvement?

I like this better. Should IColChooserModel extend HoistModel in case someone wanted to access members of HoistModel?

As far as naming conventions, have we used the "I" prefix before? I understand it here to avoid colliding with the concrete implementations, but from what I gather the general Typescript community tends to discourage it as opposed to in Java, C#, etc. Here's Microsoft's internal Typescript coding guidelines, which they emphasize only apply to TS contributors, but still could be worth noting: https://github.com/microsoft/TypeScript/wiki/Coding-guidelines. See (2) under Names (Do not use I as a prefix for interface names.)

That said, I'm not sure what else we'd call this? BaseColChooserModel? CrossPlatformColChooserModel? Maybe in this case best to stick with the prefix, but wanted to throw this out.

[amcclain]

That said, I'm not sure what else we'd call this? BaseColChooserModel? CrossPlatformColChooserModel? Maybe in this case best to stick with the prefix, but wanted to throw this out.

Yes, I also am not a fan of the I prefix, but this was exactly my dilemma. I figured if we were ever going to use it, perhaps these cross platform interfaces would be the place.

In hindsight, perhaps we should have gone with [Desktop|Mobile]ColChooserModel for the implementations... That would also have reduced likelihood of grabbing wrong import / IDE confusion. Then the interface simply ColChooserModel. Too late to consider that change?

@lbwexler not urgent but interested in your thoughts here