Added test for pivot database setting

[sroebert]

This test shows that setting the database on the Pivot entity and swapping the generic entities, does not result in the same database.

[natebird]

@sroebert, Can you provide a proposed change to the code to make this test pass?

[loganwright]

@sroebert this is an interesting case, and I'm trying to consider potential solutions. I think as a human, I can tell that Pivot<Atom, Nucleus> and Pivot<Nucleus, Atom> should essentially be the same, but the compiler sees these as distinct types that must be accounted for separately. There might be some trickery we could do, just want to be careful that we don't make other things difficult.

I imagine the issue is that you're mistyping order sometimes and getting strange bugs, maybe we could suggest typealiasing in the docs, something like:

typealias NucleusAtomPivot = Pivot<Nucleus, Atom>

might be easier to remember across a project

[tanner0101]

Thanks for submitting the failing test case! This shouldn't be too hard to fix. Just need to reference left vs. right for the database storage name.

[sroebert]

Yeah that's what I thought as well, for now I was already putting a typealias to not have to retype the full pivot everywhere.

[tanner0101]

Merging this so I can resolve it on another branch. Thanks @sroebert!