I just ran into a bug in my application in which the behavior differed
depending on whether there was a single element in a particular table
or multiple elements in the table. Right after I fixed the bug, I
thought to myself, "I wonder how I could have structured a functional
test to detect this?"
For my simple application, I am perfectly happy to use fixtures and
ActionController::TestCase. I have a fixture with multiple records in
it. If I wanted to test my application with a single record, and then
test it again with multiple records, how could I do that?