Can you simultaneously test a state change and a return value in RSpec?

Question

Say I have a method MyKlass#do_thing that I want to call exactly once in a test (because it might change a state), and that should return true on successful state change and false otherwise. I want to write a spec that looks something like this:

it "Updates myvalue if condition is met" do
  wojit = MyKlass.new

  # ... assuming condition is met
  expect { wojit.do_thing }.to change { wojit.value }.and.be true
end

But this particular approach gets an ArgumentError, because #and expects 1 argument.

I can make it work with the following abomination:

expect { expect(wojit.do_thing).to be true }.to change { wojit.value }

But that is hiiiiideous. Am I missing something more idiomatic?

Answer 1

Another approach is just to stick the return value in a variable.

return_value = nil
expect{ return_value = wojit.do_thing }.to change{ wojit.value }
expect( return_value ).to be true

YMMV as to whether it's better or worse than nested expects.