Forum: Ruby on Rails Unit test confusion

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C0228ba9997e72d80283911fd6d5d165?d=identicon&s=25 David Turnbull (Guest)
on 2006-03-19 19:32
(Received via mailing list)
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
1e90246fc67e699c32e59db89d4ff5c3?d=identicon&s=25 Michael Kaiser (Guest)
on 2006-03-19 19:52
(Received via mailing list)
Hey David,

David Turnbull 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
C1e5a9e9344b6d31b9df7303e6dc378a?d=identicon&s=25 Craig White (Guest)
on 2006-03-19 20:19
(Received via mailing list)
On Mon, 2006-03-20 at 05:32 +1100, David Turnbull 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
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