Changed the description for have_db_index to correctly describe multi…

…ple columns and index where uniqueness is not specified [#159 state:resolved]

lib/shoulda/active_record/matchers/have_db_index_matcher.rb

@@ -47,7 +47,7 @@ def negative_failure_message
         end
 
         def description
-          "have a #{index_type} index on columns #{@columns}"
+          "have a #{index_type} index on columns #{@columns.join(' and ')}"
         end
 
         protected
@@ -88,7 +88,14 @@ def expectation
         end
 
         def index_type
-          @unique ? "unique" : "non-unique"
+          case @unique
+          when nil
+            ''
+          when false
+            'non-unique'
+          else
+            'unique'
+          end
         end
 
         def normalize_columns_to_array(columns)

test/matchers/active_record/have_db_index_matcher_test.rb

@@ -70,5 +70,22 @@ class HaveDbIndexMatcherTest < ActiveSupport::TestCase # :nodoc:
       assert_rejects @matcher, Geocoding.new
     end
   end
+
+  should "join columns with and describing multiple columns" do
+    assert_match /on columns user_id and post_id/,
+      have_db_index([:user_id, :post_id]).description
+  end
+
+  should "describe a unique index as unique" do
+    assert_match /a unique index/, have_db_index(:user_id).unique(true).description
+  end
+
+  should "describe a non-unique index as non-unique" do
+    assert_match /a non-unique index/, have_db_index(:user_id).unique(false).description
+  end
+
+  should "not describe an index's uniqueness when it isn't important" do
+    assert_no_match /unique/, have_db_index(:user_id).description
+  end
 
 end