The failpoints test that the source shard of a migration behaves correctly when they receive an error response from the config server due to the failpoints. However, they do not test the CommitChunkMigration command's ability to perceive such errors, since the checks are just being arbitrarily tripped by the failpoints.

So instead, alter the config.chunks and config.locks collections directly in the JS test, in the middle of moveChunk commands, so that the CommitChunkMigration command will catch the errors on its own without failpoints doing so for the command.