Question

I’d like to be able to write a spec such as

describe Foo do
    before :each do
        @hash = some_very_expensive_setup_op
    end
    describe "hash" do
        subject{@hash}
        its([:a]){should == 10}
        its([:b]){should == 20}
        its([:c]){should == 30}
    end
end

And the way RSpec works, quite reasonably, is to execute the before block before each its block. In many cases this is what you want but in the above case and in many of my tests the final leaf its blocks are making assertions that have no side effects.

I could rewrite the spec as

describe Foo do
    before :each do
        @hash = some_very_expensive_setup_op
    end
    describe "hash" do
        it "should have some attributes" do
            @hash[:a].should == 10
            @hash[:b].should == 20
            @hash[:c].should == 30
        end
    end
end

Now all the assertions are made within a single block. The spec is functionally identical but I don’t get the juicy reporting of the first version listing each assertion in the documentation formatter.

The output is important to me because I try to use the output as documentation for consumers of the web api. For example for one of my specs I have an output like

GET /status.json?ago=:ago
  it should behave like authenticated
    GET /status.json
      accepts a valid user
      rejects an invalid user
  request
    request attributes
      :ago - number of seconds of history to calculate statistics
      :current_user ( implicit )
    response attributes
      scale
      downtime
      points
      nextlevel

But as the number of attributes rises it slows down the specs.

Are there any solutions to this tension between fine grained reporting
output and test performance?

Answer 1

The solution is to use packages like https://github.com/LRDesign/rspec-steps

steps "Login and change password" do
   it "should show the login form" do
     visit root
     page.should have_text "Login"
   end

   it "should successfully log in" do
     fill_in :name, "Johnny User"
     click "Login"
     page.should have_text "Welcome, Johnny!"
   end

   it "should load the password change form" do 
     click "My Settings"
     click "Update Password"
     page.should have_selector("form#update_password")
   end     

   it "should change the user's password successfully" do
     fill_in :password, "foobar"
     fill_in :password_confirmation, "foobar"
     click "Change Password"
     page.should have_text "Password changed successfully!"
     User.find_by_name("Johnny User").valid_password?("foobar").should be_true 
   end

 end

State is maintained between it calls you can test a sequence of steps if you like.