Use Case

As a Node.js driver user performing using toArray on my cursors
I want to lower the cost of iterating through each document
So that I can get better performance from the API

This optimization exists in v3:
https://github.com/mongodb/node-mongodb-native/blob/v3.7.4/lib/cursor.js#L861-L864

User Impact

• Performance improvement

Dependencies

• All cursor usages but no functional change

Unknowns

• Internally representing the change in Typescript

Acceptance Criteria

Implementation Requirements

• Update toArray to:
  • consume entire batches as they arrive
  • use arrays returned from BSON to extend the local array being built (do not use LL)
  • toArray can apply document transformations to the final array if a transform was given

• Address the following associated tech debt:
  • Move kDocuments to private "documents"
  • Store calculated getMoreOptions
    • only a runCursorCommand cursor can change getMore options after the first getMore operation

Testing Requirements

• Assert arrays from BSON are used directly
• Assert List is not used for toArray

Documentation Requirements

• None

Follow Up Requirements

• None