# Unit tests - NilClass problem **URL:** \ **Category:** Rails\ **Created:** [August 11, 2006, 7:22am UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133 "2006-08-11T07:22:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\ **Post date:** [August 11, 2006, 7:22am UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133/1 "2006-08-11T07:22:25Z")
Hi! Yesterday I started to write my unit tests for the fist time using rails. I’m using this method: [http://blog.codahale.com/2005/12/23/a-rails-howto-simplify-your-unit-tests/](http://blog.codahale.com/2005/12/23/a-rails-howto-simplify-your-unit-tests/) My customer\_test.rb looks like this: require File.dirname( **FILE** ) + ‘/…/test\_helper’ class CustomerTest \< Test::Unit::TestCase fixtures :customers # Replace this with your real tests. def test\_create test\_creation\_of :model =\> Customer, :record =\> @customer, :fixture =\> @first, :attributes =\> [:id, :name, :contact\_firstname, :contact\_lastname, :contact\_address, :contact\_country, :contact\_state, :contact\_email, :contact\_phone, :activationcode] end end ## and when trying to run it I get: Loaded suite customer\_test Started F Finished in 0.731 seconds. 1. Failure: test\_create(CustomerTest) [./…/test\_helper.rb:31:in `test_creation_of' customer_test.rb:13:in `test\_create’]: expected to be kind\_of? but was . ## 1 tests, 1 assertions, 1 failures, 0 errors" Any idea what might be wrong here? Thanks, John ---
**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\ **Post date:** [August 11, 2006, 10:56am UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133/2 "2006-08-11T10:56:20Z")
Reading through the article, but not actually testing the code, I think the problem is with @customer. You should have a value for @customer. Maybe you can add @customer = Customer.find(1) Topher John M. wrote: > Hi! > > Yesterday I started to write my unit tests for the fist time using > rails. I’m using this method: > [http://blog.codahale.com/2005/12/23/a-rails-howto-simplify-your-unit-tests/](http://blog.codahale.com/2005/12/23/a-rails-howto-simplify-your-unit-tests/) > > My customer\_test.rb looks like this: > require File.dirname( **FILE** ) + ‘/…/test\_helper’ > > class CustomerTest \< Test::Unit::TestCase > fixtures :customers > > # Replace this with your real tests. > > def test\_create > test\_creation\_of :model =\> Customer, > :record =\> @customer, > :fixture =\> @first, > :attributes =\> [:id, :name, :contact\_firstname, > :contact\_lastname, :contact\_address, :contact\_country, :contact\_state, > :contact\_email, :contact\_phone, :activationcode] > end > end > > ## and when trying to run it I get: > > Loaded suite customer\_test > Started > F > Finished in 0.731 seconds. > > 1. Failure: > test\_create(CustomerTest) > [./…/test\_helper.rb:31:in `test_creation_of' customer_test.rb:13:in `test\_create’]: > > expected to be kind\_of? > but was > . > > 1 tests, 1 assertions, 1 failures, 0 errors" ---
**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\ **Post date:** [August 11, 2006, 1:44pm UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133/3 "2006-08-11T13:44:14Z")
topher wrote: > Reading through the article, but not actually testing the code, I think > the problem is with @customer. You should have a value for @customer. > Maybe you can add @customer = Customer.find(1) ## Yeah, I bet I need that one. I think we’re progressing here, but now I’m getting this: 1. Error: test\_create(CustomerTest): RuntimeError: Called id for nil, which would mistakenly be 4 – if you really wa nted the id of nil, use object\_id ./test/unit/…/test\_helper.rb:33:in `send' ./test/unit/../test_helper.rb:33:in`test\_creation\_of’ ./test/unit/…/test\_helper.rb:32:in `each' ./test/unit/../test_helper.rb:32:in`test\_creation\_of’ test/unit/testcase\_test.rb:13:in `test\_create’ ## 1 tests, 1 assertions, 0 failures, 1 errors Thanks already for your help Topher! If you have any more ideas please keep’em coming 🙂 I’ll try to play with this now and see if I can solve it. ---
**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\ **Post date:** [August 15, 2006, 12:50am UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133/4 "2006-08-15T00:50:56Z")
John M. wrote: > topher wrote: > > > Reading through the article, but not actually testing the code, I think > > the problem is with @customer. You should have a value for @customer. > > Maybe you can add @customer = Customer.find(1) > > ## Yeah, I bet I need that one. I think we’re progressing here, but now I’m getting this: > > 1. Error: > test\_create(CustomerTest): > RuntimeError: Called id for nil, which would mistakenly be 4 – if you > really wa > nted the id of nil, use object\_id > ./test/unit/…/test\_helper.rb:33:in `send' ./test/unit/../test_helper.rb:33:in`test\_creation\_of’ > ./test/unit/…/test\_helper.rb:32:in `each' ./test/unit/../test_helper.rb:32:in`test\_creation\_of’ > test/unit/testcase\_test.rb:13:in `test\_create’ > > ## 1 tests, 1 assertions, 0 failures, 1 errors > > Thanks already for your help Topher! If you have any more ideas please > keep’em coming 🙂 I’ll try to play with this now and see if I can solve > it. Personally I wouldn’t bother trying to follow the article suggested by that article - all you are doing in testing ActiveRecord provided CRUD functionality is duplicate tests already present in ActiveRecord’s own test suite. Focus on testing your model’s behaviour, constraints and validations, not on stuff tested elsewhere. (unit tests shouldn’t even talk to the database, strictly speaking, but thats an article for another time). ---
**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\ **Post date:** [August 15, 2006, 2:18pm UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133/5 "2006-08-15T14:18:31Z")
It looks like the article may have been written assuming the use of instantiated\_fixtures. Maybe you could replace @customer with customers(:customer). Note, I haven’t read the article so could be well off the mark with this. Chris ---
**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\ **Post date:** [August 15, 2006, 2:16pm UTC](https://www.ruby-forum.com/t/unit-tests-nilclass-problem/102133/6 "2006-08-15T14:16:51Z")
Not having used Coda’s technique, my guess is you haven’t enhanced your fixtures to have all the necessary attributes. Assuming you created your Customer model with a generator, you should look in test/fixtures/customers.yml. The first record has the name “first” and an id attribute. You’ll need to manually add the remaining attributes (along with values for each): :name, :contact\_firstname, :contact\_lastname, :contact\_address, :contact\_country, :contact\_state, :contact\_email, :contact\_phone, :activationcode HTH, Colin On 8/11/06, John M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > RuntimeError: Called id for nil, which would mistakenly be 4 – if you > > Thanks already for your help Topher! If you have any more ideas please > keep’em coming 🙂 I’ll try to play with this now and see if I can solve > it. – Colin Strasser Union Square Internet Development 917.723.6930 (m) 646.219.0332 (f)