Projections with MultiTenantedWithSingleServer enabled

[AlexZeitler]

As already discussed on Twitter, I'm curious how to create projections across tenants when MultiTenantedWithSingleServer is being used.

I've created a repo here.

Let's pretend I have a ActiveUser projection (actually it is here) in each tenant and I want to know the number of active users across all tenants (of course there are other ways to achieve this).

Ideally, I would have something like this:

session.QueryForAllTenants<ActiveUser>()

However, this is not possible (yet) but there seem to be ideas for workarounds by @jeremydmiller...

There are some tests to make sure things work inside tenants.