Refactor have_db_index_matcher#correct_unique?

Currently, there is an assumption that `matched_index.unique` will
be `true` and not truthy. This is not always the case. This can
cause tests to fail, even though they should pass. This allows
`matched_index.unique` to be truthy.

gemfiles/3.0.gemfile.lock

@@ -1,5 +1,5 @@
 PATH
-  remote: /Users/joshuaclayton/dev/gems/shoulda-matchers
+  remote: /home/mike/thoughtbot/shoulda-matchers
   specs:
     shoulda-matchers (1.3.0)
       activesupport (>= 3.0.0)

gemfiles/3.1.gemfile.lock

@@ -1,5 +1,5 @@
 PATH
-  remote: /Users/joshuaclayton/dev/gems/shoulda-matchers
+  remote: /home/mike/thoughtbot/shoulda-matchers
   specs:
     shoulda-matchers (1.3.0)
       activesupport (>= 3.0.0)
@@ -46,7 +46,7 @@ GEM
       rspec (>= 2.7.0)
     bourne (1.1.2)
       mocha (= 0.10.5)
-    builder (3.0.0)
+    builder (3.0.3)
     childprocess (0.3.5)
       ffi (~> 1.0, >= 1.0.6)
     cucumber (1.1.9)
@@ -61,8 +61,8 @@ GEM
     gherkin (2.9.3)
       json (>= 1.4.6)
     hike (1.2.1)
-    i18n (0.6.0)
-    jquery-rails (2.1.1)
+    i18n (0.6.1)
+    jquery-rails (2.1.2)
       railties (>= 3.1.0, < 5.0)
       thor (~> 0.14)
     json (1.7.5)

gemfiles/3.2.gemfile.lock

@@ -1,5 +1,5 @@
 PATH
-  remote: /Users/joshuaclayton/dev/gems/shoulda-matchers
+  remote: /home/mike/thoughtbot/shoulda-matchers
   specs:
     shoulda-matchers (1.3.0)
       activesupport (>= 3.0.0)
@@ -45,7 +45,7 @@ GEM
       rspec (>= 2.7.0)
     bourne (1.1.2)
       mocha (= 0.10.5)
-    builder (3.0.0)
+    builder (3.0.3)
     childprocess (0.3.5)
       ffi (~> 1.0, >= 1.0.6)
     cucumber (1.1.9)
@@ -60,9 +60,9 @@ GEM
     gherkin (2.9.3)
       json (>= 1.4.6)
     hike (1.2.1)
-    i18n (0.6.0)
+    i18n (0.6.1)
     journey (1.0.4)
-    jquery-rails (2.1.1)
+    jquery-rails (2.1.2)
       railties (>= 3.1.0, < 5.0)
       thor (~> 0.14)
     json (1.7.5)

lib/shoulda/matchers/active_record/have_db_index_matcher.rb

@@ -62,13 +62,16 @@ module Shoulda # :nodoc:
         def correct_unique?
           return true unless @options.key?(:unique)
 
-          if matched_index.unique == @options[:unique]
-            true
-          else
+          is_unique = matched_index.unique
+
+          is_unique = !is_unique unless @options[:unique]
+
+          unless is_unique
             @missing = "#{table_name} has an index named #{matched_index.name} " <<
-                       "of unique #{matched_index.unique}, not #{@options[:unique]}."
-            false
+            "of unique #{matched_index.unique}, not #{@options[:unique]}."
           end
+
+          is_unique
         end
 
         def matched_index

spec/shoulda/active_record/have_db_index_matcher_spec.rb

@@ -85,4 +85,21 @@ describe Shoulda::Matchers::ActiveRecord::HaveDbIndexMatcher do
   it "should not context an index's uniqueness when it isn't important" do
     have_db_index(:user_id).description.should_not =~ /unique/
   end
+
+  it "allows an IndexDefinition to have a truthy value for unique" do
+    db_connection = create_table 'superheros' do |table|
+      table.integer :age
+    end
+    db_connection.add_index :superheros, :age
+    define_model_class 'Superhero'
+
+    @matcher = have_db_index(:age).unique(true)
+
+    index_definition = stub("ActiveRecord::ConnectionAdapters::IndexDefinition",
+                            :unique => 7,
+                            :name => :age)
+    @matcher.stubs(:matched_index => index_definition)
+
+    Superhero.new.should @matcher
+  end
 end