This is the wrong approach. He should be putting data in the database schema before trying to run migrations on it.
Doing that is simple and can potentially catch all sorts of bugs, including the bugs you didn't think of yet. His solution is complicated but only catches one very specific type of bug.
Doing that is simple and can potentially catch all sorts of bugs, including the bugs you didn't think of yet. His solution is complicated but only catches one very specific type of bug.