The ReshardingOplogApplicationRules class is currently tested in C++ through these tests cases in resharding_oplog_applier_test.cpp. Resharding's oplog application rules behave the same when called from ReshardingOplogApplier::applyUntilCloneFinishedTs() as they do when called from ReshardingOplogApplier::applyUntilDone(). Testing the behavior through ReshardingOplogApplier adds an extra layer of orchestration and complexity for something that has already been split out into its own class. We should instead rewrite these C++ tests to call ReshardingOplogApplicationRules::applyOperation() directly.