Summary

When using unacknowledged writes in the session spec prohibits combining sessions with unacknowledged write concerns. There does not appear to be any common test coverage for this.

Consider adding the following:

• Spec test to assert that a client-side error is raised and no command is issued when combining an explicit session with an unacknowledged write concern
• Spec test to assert that an unacknowledged write does not include an LSID, which could address the guidance for implicit sessions

These tests could live in either the session or CRUD spec. The triage team can decide if it's worth exhaustively testing each write method, or if it'd be sufficient to focus on one (e.g. insertOne).

Motivation

Is this issue urgent?

No.

Is this ticket required by a downstream team?

No.

Is this ticket only for tests?

Yes.