User Story

As an application developer

I do not want the driver to throw an error when I explain an aggregation with a writeConcern

So I can get the correct server response with the queryPlanner results.

Use Case

The AggregateOperation constructor has logic to throw an error if an aggregation is constructed with explain and writeConcern set (https://github.com/mongodb/node-mongodb-native/blob/5b3d01b824587dfa75f36ef9e55f6559d5fc5fe9/src/operations/aggregate.ts#L71).  Instead, the node driver should not throw an error and rely on the server response, which ignores the option.

User Impact

The server does not error in this case so user catch blocks will just become dead code.

Dependencies

Unknowns

• None.

Acceptance Criteria

Implementation Requirements

• Remove the writeConcern check and throwing of the MongoInvalidArgumentError

Testing Requirements

• Change any tests asserting this throws to asseting an explain result is returned. If none exist then add a new test to avoid regressions. Edit: This will still throw.

Documentation Requirements

• Note in the release notes that this scenario will no longer throw and will return the correct results from the server.

Follow Up Requirements

• n/a