Proposal: .import should accept array-like objects

[mattvague]

Hi there, I was recently trying to do something like

things = Thing.where(attr: 'baz').each { |t| t.other_attr = 'bar' }
Thing.import(things)

and was confused about why I was getting a ArgumentError: Invalid arguments! error. As pointed out in this issue, simply calling Thing.import(things.to_a) would fix things since things would be an ActiveRecord_Relation however, I'd like to propose that .import should be more liberal in what it accepts and that this should be a valid use case.

Instead of doing strict args.last.is_a?( Array ) checks like this should instead maybe check if args.last responds to to_a and if so then calls that first.

Also, maybe we could improve these error message a bit to be more specific about why the arguments are invalid?