Fixed "strange statistics"

[skmedix]

Fixes flarum/framework#2528

Before:

After:

[askvortsov1]

Makes sense to me! One quick question before approving: how would a non-integer value get processed in the first place? In addition to validating here, we might also want to ensure that we're only dealing with integers throughout the process.

[skmedix]

@askvortsov1 This is a great question, but unfortunately I don't have answer for it yet. This behavior is really inconsistent between machines, and I can't find the real cause of it, but I added an additional casting in the backend though.

From my debug session, it must happens before any data manipulation, as results has already wrong type after the first query.
When I dumped the results variable on both of my machines, one machine output'ed:
array(1) { ["2020-12-23"]=> int(1) } }
which is correct, by second machine output'ed:
array(1) { ["2019-12-23"]=> string(1) "1" } }

In the future I would like to make even more precise debug with dockerized examples, but it should be good for now. :)

[askvortsov1]

Either way, I'm in favor of the additional validation / type casting.