Mongoid has one place in master where it calls `collection.find.aggregate`.:

lib/mongoid/contextual/aggregable/mongo.rb:          result = collection.find.aggregate(pipeline(field), session: _session).to_a

This usage can cause issues if https://jira.mongodb.org/browse/RUBY-2797 is implemented to pass find view parameters to the aggregation pipeline.

Mongoid should simply invoke aggregate directly on the collection, as is documented in https://www.mongodb.com/docs/ruby-driver/master/reference/aggregation/.