Failing to explicitly set position can lead to reordering on update

[CodingAnarchy]

Having a record that is not set to a position defaults to :last, but this causes the record to inadvertently be moved to the last position whenever there is an update to the already saved record.

Specifically, this case will give an odd result:

class Foo < ActiveRecord::Base
    include RankedModel
    
    ranks :row_order
end

r = Foo.create()
other = Foo.create()
r.update(some_field: "new_value") # <= This line will also update the row_order field

This same behavior does not occur if you fetch the record from the database directly - the row_order will be static in that case.

I ran into this issue with some usage of the pattern in tests to create the object, then update it, reload, and verify the ordering.

[brendon]

That's interesting. I guess it's a downside of the underlying database state changing at save but not being updated in the object itself. I'm not sure what the answer is here. Did you want to explore a PR around populating the row_order on save if it's inferred?

[CodingAnarchy]

@brendon I can definitely look into it, sure.

[brendon]

Thanks for cleaning up :D