Fix performance bug for which selectors were not being cached

[xantorres]

After a lot of headaches finding my components being rendered again and again because of selectors getting called, I think I finally found the issue.

[mariusandra]

Wow! That's a nasty bug! 🐞
Thanks for fixing it! I'll release a new patch version right away.

[mariusandra]

v0.27.6 released. I did add back the !! as I can't trust the cache to return a boolean. It might return undefined and then !==ing it with a boolean will always be false. Not sure if that'll have real world consequences, but I'd like to be safe :).

[xantorres]

Why don't you just use != then?

[mariusandra]

That's a valid question. The reason's simple: ESLint complains about it and I might overlook it and "fix" back to "!==" one day when refactoring.

I could of course use != and leave a comment... or add a // eslint-disable-line, but in general I find an operator that equates a string ("5") to a number (5) to be a bit too magical for my taste, so I just prefer to not think about all these edge cases and consistently use !==.

[xantorres]

Ok, understood. And thanks for the great library btw ;) Is really awesome

[mariusandra]

I was perhaps a bit too fast when releasing the new version. I didn't run the tests and apparently the fixed code with the !! put back in place makes them fail:

Without the !! everything works. I'll investigate later if there are any deeper side effects (incl. performance), but for now I released 0.27.7 that should work as expected.