Use Case

ModernConnection is just a copy of Connection, update it to use read/write async helpers. Notably, rework command monitoring due to the fact that it is bound to callback syntax at the moment.

User Impact

• None. The old Connection will still be used.

Dependencies

• No external dependencies
• Internally, ModernConnection class, async read/write functions, socket event handling

Unknowns

• How should we handle socket errors, closing, and timeouts?
  • Using an AbortController that lives on the Connection class
• Is it a problem to reinterpret socketTimeoutMS as a total timeout of the read operation vs what it is now which is a timeout of idle-ness between chunks?
  • No it is not a problem, but we ended up not needing to with the controller and signal approach to error handling.

Acceptance Criteria

Implementation Requirements

• Remove MessageStream and socket event handling from Connection ctor
  • Except for 'close'. An idle connection in the ConnectionPool should clean it's self up if the socket closes.
• Change write(..., cb) call to the new async writeCommand
• Add a call to async read after the socket has been written to
• Perform parsing identical to the logic in onMessage
• Write error handling logic to be enabled before write and disabled after read
  • Make use of AbortController to reject i/o promises

Testing Requirements

• Integration test
  • Set an environment variable that makes the driver make connection pool connections with the new class
  • newClient will set connectionType to ModernConnection
  • Run a new typical linux suite (all versions, topologies, lb mode, serverApi)

Documentation Requirements

• None

Follow Up Requirements

• See parent for next subtasks