Marten: Calling Store then Delete on a document before SaveChanges does not Delete

[ericgreenmix]

The commands are getting executed backwards, with Delete and then Upsert. This is a regression in 1.2.5, I believe tied to ff222c0c4a5ef5823a862a977eb7d9cc90890d51

Failing test coming...

[jeremydmiller]

@ericgreenmix I'm not sure I'm buying that this is a bug. It's a pretty odd usage to me.

[ericgreenmix]

This happens quite a bit in our application when doing projection rebuilds.

[ericgreenmix]

It is odd usage in just a normal case, like the simplified unit test. However when you get into projection rebuilds it, that is a key feature we need.

[jeremydmiller]

Why is that? Why would you be both deleting and upserting the same document in the same unit of work?

[ericgreenmix]

When doing a projection rebuild using the Async Daemon, the Daemon handles calling SaveChanges. So if it has a stream of events coming in that update a document and then delete it later in the event stream, that causes the issue.

[jarroda]

When rebuilding a projection, the entire stream of events for a given aggregate is ran through in the same unit of work. Any aggregate that is ever deleted will have an upsert and deletion in the same UoW in that case.

[jeremydmiller]

Pfft, okay. I'm going to address this by making Marten perform the operations in a unit of work in the same order that they were registered w/ the session. Automatic dirty checking actions will be a little flaky with that, but we'll cross that bridge later if it's ever a problem.