Rails ActiveSupport: How to assert that an error is raised?

Question

I am wanting to test a function on one of my models that throws specific errors. The function looks something like this:

def merge(release_to_delete)
  rais         


        

Answer 1

To ensure that no exception is raised (or is successfully handled) do inside your test case:

assert_nothing_raised RuntimeError do
  whatever.merge
end

To check that error is raised do inside your test case:

assert_raise RuntimeError do
  whatever.merge
end

Just a heads up, whatever.merge is the code that raises the error (or doesn't, depending on the assertion type).