How to assert certain method is called with Ruby minitest framework?

Minitest has a special .expect :call for checking if some method is called.

describe SomeClass do
  it "should invoke right function" do
    mocked_method = MiniTest::Mock.new
    mocked_method.expect :call, return_value, []
    some_instance = SomeClass.new
    some_instance.stub :right, mocked_method do
      some_instance.invoke_function("right")
    end
    mocked_method.verify
  end
end

Unfortunately this feature is not documented very well. I found about it from here: https://github.com/seattlerb/minitest/issues/216