Migration of d7 messages with additional fields

Steven Jones → made their first commit to this issue’s fork.

When you're doing this sort of per-bundle migration because you've got different fields per-bundle, it's often useful to split the migrations out per-bundle too.

I've created an issue fork, popped the patch from #2 in there, and then added a bit of code to allow restricting the migration down to a specific bundle. Hopefully widening the scope of this issue isn't too problematic.

I'm going wild and marking this as RTBC, because the code from #2 (also in the MR) totally works really nicely, thanks!

This probably should have tests etc. but maybe in a follow up?

Thanks all!

Automatically closed - issue fixed for 2 weeks with no activity.