RSpec and HAML Helpers

Today I faced a problem with specing a helper where I use the haml_tag/puts methods (haml_tag was previously open).

Here’s a solution working with Rails 2.0.2, RSpec 1.0.3 and HAML 1.8.2 :

in spec_helper.rb add :

Spec::Runner.configure do |config|
  ...
  
  # Activate haml to spec helpers
  config.with_options(:behaviour_type => :helpers) do |config|  
    config.include Haml::Helpers  
    config.include ActionView::Helpers  
    config.prepend_before :all do  
       # Update from Evgeny comment, with HAML >= 1.8.2, you can call
       init_haml_helpers

       # Old way for HAML <= 1.8.2
       # @haml_is_haml = true  
       # @haml_stack = [Haml::Buffer.new]  
    end  
  end

  ...
end

then you can write your helper spec like this :

describe ApplicationHelper do
  describe "#top_navigation_menu when logged in" do
    it "returns the menu" do
      @user = mock_model(User)
      capture_haml {
        top_navigation_menu(@user)
      }.should_not be_empty
    end
end

The interesting method is capture_haml, which does the same as Rails builtin capture but for HAML.
haml_tag/puts methods write output directly to the buffer and does not return the generated content as a String, thus we cannot just test on the method output.

2 comments »

1. 

   By Evgeny 23/05/2008 at 13h39

   
   

   Instead of @haml_is_haml, in the new version (Haml > 1.8.2) the syntax will be just – #init_haml_helpers

   So when using edge haml, there is a shortcut.

   Strange how I wrote the same piece of code … a long time ago …
   http://blog.kesor.net/2007/07/22/writing-helpers-with-haml-and-rspec/ and it didn’t really work.

2. 

   By Jonathan Tron 23/05/2008 at 14h15

   
   

   Thanks Evgeny, I tried using #init_haml_helpers before but it never worked.
   I tried one more time after your comment and it looks like I didn’t call it in the right place as it works now.
   Great.