RSpec: how to test if a method was called?

Question

When writing RSpec tests, I find myself writing a lot of code that looks like this in order to ensure that a method was called during the execution of a test (for the sake o

Answer 1

To fully comply with RSpec ~> 3.1 syntax and rubocop-rspec's default option for rule RSpec/MessageSpies, here's what you can do with spy:

Message expectations put an example's expectation at the start, before you've invoked the code-under-test. Many developers prefer using an arrange-act-assert (or given-when-then) pattern for structuring tests. Spies are an alternate type of test double that support this pattern by allowing you to expect that a message has been received after the fact, using have_received.

# arrange.
invitation = spy('invitation')

# act.
invitation.deliver("foo@example.com")

# assert.
expect(invitation).to have_received(:deliver).with("foo@example.com")

If you don't use rubocop-rspec or using non-default option. You may, of course, use RSpec 3 default with expect.

dbl = double("Some Collaborator")
expect(dbl).to receive(:foo).with("foo@example.com")

• Official Documentation: https://relishapp.com/rspec/rspec-mocks/docs/basics/spies
• rubocop-rspec: https://docs.rubocop.org/projects/rspec/en/latest/cops_rspec/#rspecmessagespies