Problem

We don't have a clear stance on whether we support collections with client side field level encryption (CSFLE). They should just work and it's more work to error on them rather than just supporting them. We can't reliably see if a collection has CSFLE by checking the server because CSFLE is determined by the driver. Our public documentation doesn't indicate if we support them either.

Note: mongosync returns an error if a collection has document validation for client side field level encryption (CSFLE) when a doc filter is specified. However, this guardrail does not catch all CSFLE collections (i.e., ones without document validation.)

Solution & Acceptance Criteria

Add tests for CSFLE collections in mongosync (without doc filter) and in the verifier. Update our public documentation.

Impact

Confidently say that we support CSFLE collections.