System tests are used to test the application from the user's point of
view. To test for specific exceptions, particularly regarding
authorization permissions, controller tests fit better.
Another option would be to test the page displayed shows a certain text,
like "Internal server error". I'm choosing controller tests because
they're faster and we're basically testing the same scenario many times
and we've already got a test checking what happens when users access a
page raising an exception.
We were very inconsistent regarding these rules.
Personally I prefer no empty lines around blocks, clases, etc... as
recommended by the Ruby style guide [1], and they're the default values
in rubocop, so those are the settings I'm applying.
The exception is the `private` access modifier, since we were leaving
empty lines around it most of the time. That's the default rubocop rule
as well. Personally I don't have a strong preference about this one.
[1] https://rubystyle.guide/#empty-lines-around-bodies
