rspec users - Nov 2007 - Problem with view spec - works inside the browser but spec fails with nil object

Hi,

I''ve been trying to find an answer for this problem in the last couple
hours, but I think no discussion was about this exact same thing. So here it
goes, hope someone can help.

I''m trying to spec a view which works correctly on the browser, but
that
generates the following error when I run "rake spec:views".

ActionView::TemplateError in ''/survey/show should display the
"question 4"
heading correctly''
You have a nil object when you didn''t expect it!
The error occurred while evaluating nil.position
On line #1 of app/views/survey/_question_for_candidate.rhtml

    1: <div class="question question-<%= question.position
%>">
    2:   <p class="heading">
    3:     <span class="number"><%= question.position
%>.</span>
    4:     <span class="description"><%= question.description
%></span>

RSpec is telling me that the "question" object is nil. I
can''t figure it out
why.

Here''s the spec that generates the error (the "it" block
should test some
tags inside the "response" object):

require File.dirname(__FILE__) + ''/../../spec_helper''

describe ''/survey/show'' do
  fixtures ''questions'', ''alternatives''

  before(:each) do
    assigns[:configurations] = {:survey_name => ''Whatever''}
    assigns[:questions] = Array.new
    assigns[:questions][4] = questions(:faixa_etaria)
    @faixa_etaria = questions(:faixa_etaria)
  end

  it ''should display the "question 4" heading
correctly'' do
    render ''survey/show''
  end
end

Here''s the :faixa_etaria Question fixture I''m using:

faixa_etaria:
  id: 1
  question_type_id: 1
  description: ''Em qual das faixas et?rias abaixo voc? se
inclui?''
  position: 4

(The description value is in Portuguese).

Here''s the "show" method inside the SurveyController:

  def show
    @configurations = {}
    Configuration.find(:all).each { |c| @configurations[c.name.to_sym] c.value }
    @questions = {}
    Question.find(:all).each { |q| @questions[q.position] = q }
  end


Here''s the piece of code inside the "show.rhtml" template
that''s calling the
helper method that will cause that error:

<%= render_question(@questions[4]) %>

Here''s the "render_question" method implementation, inside
the SurveyHelper
class (invoking "render" seems to be the problem, but I don''t
know why):

  def render_question(question)
    render(:partial => ''question_for_candidate'', :locals
=> {:question =>
question})
  end

The :locals Hash has :question as a key, and that is the variable that RSpec
is complaining about inside the partial.

Finally, here''s the "question_for_candidate" partial:

<div class="question question-<%= question.position %>">
  <p class="heading">
    <span class="number"><%= question.position
%>.</span>
    <span class="description"><%= question.description
%></span>
  </p>
  <% for alternative in question.alternatives -%>
    <%= radio_button ''candidate'',
"question_#{question.id}", alternative.id%>
    <label for="candidate_question"><%=
alternative.description %></label>
    <br />
  <% end -%>
</div>

I''m not that experienced with Rails nor RSpec, so I''m totally
lost about
this problem.

-- 
Caio Moritz Ronchi
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You are trying to test a lot of things at the same time, which is one of
the reasons that it is now hard to diagnose a problem.

I would tackle this by 
a) writing a separate spec for the partial _question_for_candidate
b) write a separate spec for the helper that renders the question
b) in the view spec for /survey/show use should_receive to determine
that the helper is actually being called
c) not use any fixtures in the view specs but instead use mocks for
that: it''s faster and you can check exactly what needs to happen
instead
of relying on what happens to be in the fixture.

I''m afraid that I don''t see immediately why your current setup
won''t
work, but untangling things along the lines sketched above should
hopefully get you to a situation where it becomes easier to see what
happens.
>   before(:each) do
>     assigns[:configurations] = {:survey_name =>
''Whatever''}
>     assigns[:questions] = Array.new
>     assigns[:questions][4] = questions(:faixa_etaria)
I am a little bit suspicious about this construction, though. I''m not
sure whether assigns is a normal Array in this case, so I''d create the
Array and populate it before handing it to assigns:

@questions = Array.new
@questions[4] = ...
assigns[:questions] = @questions

Kind regards,

Hans
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Hi Hans,

I rewrote my specs the way you suggested and now everything works!

For those who are interested, here''s how the code looks like now (after
following Hans'' tips).
> a) writing a separate spec for the partial _question_for_candidate
require File.dirname(__FILE__) + ''/../../spec_helper''

module QuestionForCandidatePartialHelper
  def get_question_type_mock(type)
    mock_model(QuestionType, {:name => type})
  end

  def render_question_for_candidate_partial
    render(:partial => ''survey/question_for_candidate'',
:locals =>
{:question => @question})
  end
end

describe ''partial survey/_question_for_candidate.rhtml'' do
  include QuestionForCandidatePartialHelper

  before(:each) do
    @question = mock_model(Question, {
      :id => 1,
      :description => ''The description'',
      :position => 4,
      :alternatives => [mock_model(Alternative, {:id => 1, :description
=>
''Alternative 1 Description''})],
    })
    @question_type_exclusive =
get_question_type_mock(''exclusive'')
    @question_type_multiple =
get_question_type_mock(''multiple'')
  end

  it ''should render the top of the template no matter the question
type'' do
    @question.stub!(:question_type).and_return(@question_type_exclusive)
    render_question_for_candidate_partial
    response.should have_tag(''div.question.question-4'') do
      with_tag(''.heading .number'', ''4.'')
      with_tag(''.heading .description'', @question.description)
    end
  end

  it ''should render an exclusive-answer question'' do
    @question.stub!(:question_type).and_return(@question_type_exclusive)
    render_question_for_candidate_partial
    response.should have_tag(''div.question.question-4'') do
      with_tag(''input[type=?]'', ''radio'')
      without_tag(''input[type=?]'',
''checkbox'')
    end
  end

  it ''should render a multiple-answer question'' do
    @question.stub!(:question_type).and_return(@question_type_multiple)
    render_question_for_candidate_partial
    response.should have_tag(''div.question.question-4'') do
      with_tag(''input[type=?]'', ''checkbox'')
      without_tag(''input[type=?]'', ''radio'')
    end
  end
end
> b) write a separate spec for the helper that renders the question
require File.dirname(__FILE__) + ''/../spec_helper''

describe SurveyHelper do
  before(:each) do
    @question = mock_model(Question)
  end

  it ''should render a question using the question_for_candidate
partial'' do
    self.should_receive(:render).with(:partial =>
''question_for_candidate'',
:locals => {:question => @question})
    render_question(@question)
  end
end
> b) in the view spec for /survey/show use should_receive to determine
that the helper is actually being called

require File.dirname(__FILE__) + ''/../../spec_helper''

describe ''/survey/show'' do
  before(:each) do
    assigns[:configurations] = {:survey_name => ''Whatever''}
    @positions = [4, (9..22).to_a].flatten
    @questions = Array.new
    @positions.each do |position|
      @questions[position] = mock_model(Question, {
        :id => 1,
        :description => ''The description'',
        :position => 4,
        :alternatives => [mock_model(Alternative, {:id => 1, :description
=>
''Description''})],
        :question_type => mock_model(QuestionType, {:name =>
''exclusive''})
      })
    end
    assigns[:questions] = @questions
  end

  it "should render the ''survey/question_for_candidate''
partial" do
    args = {:partial => ''question_for_candidate'', :locals
=> {:question =>
an_instance_of(Question)}}
    template.should_receive(:render).with(args).exactly(@questions.nitems
).times
    render ''survey/show''
  end
end

c) not use any fixtures in the view specs but instead use mocks for
that: it''s faster and you can check exactly what needs to happen
instead
of relying on what happens to be in the fixture.

As you can see mocks are now all over the place. No fixtures were used ;)

Thanks a lot,

Caio

On Nov 11, 2007 6:01 AM, Hans de Graaff <hans at degraaff.org> wrote:
> You are trying to test a lot of things at the same time, which is one of
> the reasons that it is now hard to diagnose a problem.
>
> I would tackle this by
> a) writing a separate spec for the partial _question_for_candidate
> b) write a separate spec for the helper that renders the question
> b) in the view spec for /survey/show use should_receive to determine
> that the helper is actually being called
> c) not use any fixtures in the view specs but instead use mocks for
> that: it''s faster and you can check exactly what needs to happen
instead
> of relying on what happens to be in the fixture.
>
> I''m afraid that I don''t see immediately why your current
setup won''t
> work, but untangling things along the lines sketched above should
> hopefully get you to a situation where it becomes easier to see what
> happens.
>
> >   before(:each) do
> >     assigns[:configurations] = {:survey_name =>
''Whatever''}
> >     assigns[:questions] = Array.new
> >     assigns[:questions][4] = questions(:faixa_etaria)
>
> I am a little bit suspicious about this construction, though. I''m
not
> sure whether assigns is a normal Array in this case, so I''d create
the
> Array and populate it before handing it to assigns:
>
> @questions = Array.new
> @questions[4] = ...
> assigns[:questions] = @questions
>
> Kind regards,
>
> Hans
>
> _______________________________________________
> rspec-users mailing list
> rspec-users at rubyforge.org
> http://rubyforge.org/mailman/listinfo/rspec-users
>


-- 
Caio Moritz Ronchi
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