Testing page.alert

Hello,

Testing newbie here. I have some AJAX code that would render an error
message back to the host using page.alert. How would I test that?
Personally I use RSpec, but Test::Unit is also fine. Thanks.

# If some error arises
render :update do |page|
  page.alert("Error message!")
end

Here's how you can do it with rspec:

describe "some action" do
  it "should alert with Error message!" do
    page = mock("page")
    page.should_receive(:alert).with("Error message!")
    controller.expect_render(:update).and_yield(page)
    get :some_action
  end
end

Here's how I *think* (haven't tried it, but should work) you can do it
with test/unit and mocha:

def test_alert_with_error_messaged
    page = mock()
    page.expects(:alert).with("Error message!")
    @controller.expects(:update).yields(page)
    get :some_action
end

Cheers,
David