Pull in Viget posts

content/elsewhere/shoulda-macros-with-blocks/index.md

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+---
+title: "Shoulda Macros with Blocks"
+date: 2009-04-29T00:00:00+00:00
+draft: false
+needs_review: true
+canonical_url: https://www.viget.com/articles/shoulda-macros-with-blocks/
+---
+
+When I'm not working on client projects, I keep myself busy
+with [SpeakerRate](http://speakerrate.com), a site that lets conference
+goers rate the talks they've attended. After a number of similar
+suggestions from users, we decided to display the total number of
+ratings alongside the averages. Although only talks can be rated,
+speakers, events and series also have ratings through their associated
+talks. As you can imagine, calculating the total ratings for each of
+these required a lot of somewhat repetitive code in the models, and
+*very* repetitive code in the associated tests.
+
+Fortunately, since we're using
+[Shoulda](http://thoughtbot.com/projects/shoulda/), we were able to DRY
+things up considerably with a macro:
+
+``` {#code .ruby}
+class Test::Unit::TestCase def self.should_sum_total_ratings klass = model_class context "finding total ratings" do setup do @ratable = Factory(klass.to_s.downcase) end should "have zero total ratings if no rated talks" do assert_equal 0, @ratable.total_ratings end should "have one total rating if one delivery & content rating" do talk = block_given? ? yield(@ratable) : @ratable Factory(:content_rating, :talk => talk) Factory(:delivery_rating, :talk => talk) assert_equal 1, @ratable.reload.total_ratings end end end end 
+```
+
+This way, if we're testing a talk, we can just say:
+
+``` {#code .ruby}
+class TalkTest < Test::Unit::TestCase context "A Talk" do should_sum_total_ratings end end 
+```
+
+But if we're testing something that has a relationship with multiple
+talks, our macro accepts a block that serves as a factory to create a
+talk with the appropriate relationship. For events, we can do something
+like:
+
+``` {#code .ruby}
+class EventTest < Test::Unit::TestCase context "An Event" do should_sum_total_ratings do |event| Factory(:talk, :event => event) end end end 
+```
+
+I\'m pretty happy with this solution, but having to type "event" three
+times still seems a little verbose. If you\'ve got any suggestions for
+refactoring, let us know in the comments.
+
+