Unit test confusion


#1

Hey all,

I’m following along with AWDWR, specifically the unit testing.
On page 148, it shows you how Test::Unit::TestCase will automatically
define instance variables based on your fixtures.

It doesn’t seem to actually work, though. It seems that both @artists
[“beatles”][“name”] and @beatles.name are nil objects in my test,
where as artists(:beatles).name works ok.

What is the right way of doing it? I’d guess the one that actually
works is right, but there’s a lot of stuff on google about the other
ways that I can’t get to work.

The actual error messages for the failed assertions are different:

@artists[“beatles”][“name”]:

test_create(ArtistTest):
NoMethodError: You have a nil object when you didn’t expect it!
The error occured while evaluating nil.name
test/unit/artist_test.rb:15:in `test_create’

@beatles.name:

test_create(ArtistTest):
NoMethodError: You have a nil object when you didn’t expect it!
You might have expected an instance of Array.
The error occured while evaluating nil.[]
test/unit/artist_test.rb:14:in `test_create’

test/fixtures/artists.yml:

beatles:
id: 1
name: The Beatles

test/unit/artist_test.rb:

require File.dirname(FILE) + ‘/…/test_helper’

class ArtistTest < Test::Unit::TestCase
fixtures :artists

 def setup
     @artist = Artist.find(1)
 end

 def test_create
     assert_equal @artists["beatles"]["name"], @artist.name    #

fails
assert_equal @beatles.name, @artist.name #
fails
assert_equal artists(:beatles).name, @artist.name #
works
end
end


#2

Hey David,

David T. wrote:

What is the right way of doing it? I’d guess the one that actually
works is right, but there’s a lot of stuff on google about the other
ways that I can’t get to work.

You have to set

self.use_instantiated_fixtures = true

in test_helper.rb for this to work.

Michael


#3

On Mon, 2006-03-20 at 05:32 +1100, David T. wrote:

What is the right way of doing it? I’d guess the one that actually
The error occured while evaluating nil.name

     assert_equal @beatles.name, @artist.name                  #  

fails
assert_equal artists(:beatles).name, @artist.name #
works
end
end


I believe that Dave has suggested that his section on testing is
somewhat broken and it would probably be a very good idea to read
through the errata page before wasting too much time on it.

http://books.pragprog.com/titles/rails/errata

Craig