alphagov/panopticon — comment on commit 938e126b3000d0f64a34a8b31e3c7cd566cad3fa
File:  line 0
By threedaymonk:

> Handy for detecting when someone has checked in a bad migration without running it

I'm not sure that's true: AR::Migration loads the class, but doesn't actually run anything if the schema says it's been done.

> or if someone has forgotten to check in the updated `schema.rb`

If you forget to update the schema but run migrations, the migration will run and everything will work, no?

I'm not sure that there's any way to prove that migrations do what they're supposed to short of running them on actual data, which is one of the things that preview does for us.