From: Phlip <phlipcpp@...>
Date: 2007-09-03T12:10:08+09:00
Subject: Re: about assert_difference problem. help!!

OnRails Ruby wrote:

>  def test_should_create_person
>    assert_difference people, :count do
>  person=Person.newly_created

How is assert_difference expected to inflect "people" into "Person"? Or is 
people declared somewhere else?

Use assert_latest:

  person = assert_latest Person do
    Person.newly_created  #  <-- you supply this, right?
  end
  assert person.new_record?

Note that assert_latest returns nil, one item, or an [] array of items. So 
calling .new_record? on its return value is itself a test that one item 
appeared.

>      assert !person.new_record?,
> "#{person.errors.full_messages.to_sentence}"

That line says to flunk if person is not a new record; is this what you 
wanted?

> people.yml
> test1:

Both assert_difference (which comes from various plugins, not from Rails) 
and assert_latest (which comes from 
http://www.oreillynet.com/onlamp/blog/2007/07/assert_latest_and_greatest.html ) 
don't detect fixtures, because they appear just before setup() time.

-- 
  Phlip
  http://www.oreilly.com/catalog/9780596510657/
  "Test Driven Ajax (on Rails)"
  assert_xpath, assert_javascript, & assert_ajax