Which method starts a transaction, runs a callback, and then commits or cancels the transaction?

The method that starts a transaction, runs a callback, and then commits or cancels the transaction is indeed withTransaction(). This method is designed to facilitate working with transactions in MongoDB in a clean and effective manner.

When using withTransaction(), you provide it with a session and a callback function that contains your transactional logic. The method takes care of beginning the transaction, executing the callback, and then handling the commit or aborting based on the outcome of the callback. This abstraction simplifies the transaction handling process by ensuring that the necessary steps—starting the transaction, performing operations, and committing or rolling back—are managed within a single method call.

This structured approach effectively minimizes the risk of human error when managing transactions, as it encapsulates all of the transaction stages and maintains code clarity. With the responsibility for starting, committing, or aborting managed by the method itself, developers can focus more on the operations they want to perform within the transaction rather than the mechanics of its lifecycle.