WIP: Fix positve error description spec issues and add method for mat…

…ched_error.

lib/shoulda/matchers/active_model/positive_error_description.rb

@@ -17,6 +17,14 @@ def matches?
           end
         end
 
+        def matched_error
+          if @expected_message
+            error_matching_expected || ""
+          else
+            first_error_message
+          end
+        end
+
         private
 
         def error_message_matches_string?
@@ -33,6 +41,16 @@ def error_message_matches_regexp?
           end
         end
 
+        def error_matching_expected
+          errors_for_attribute.select do |error|
+            @expected_message.match(error)
+          end.first
+        end
+
+        def first_error_message
+          errors_for_attribute.first.to_s
+        end
+
         def errors_for_attribute
           valid?
           Array.wrap(@instance.errors[@attribute])

spec/shoulda/active_model/positive_error_description_spec.rb

@@ -20,7 +20,6 @@
 
   context 'with an error that matches the expected message regexp' do
     it 'returns the matched error' do
-      define_model(:Example, :attr => :string) do
       define_model(:Example, :attr => :string) do
         validates :attr, :presence => true
       end
@@ -31,6 +30,7 @@
 
   context 'with an error that matches the expected message regexp' do
     it 'returns the matched error' do
+      define_model(:Example, :attr => :string) do
         validates :attr, :presence => true
       end
       positive_error_description = described_class.new(Example.new, :attr, '', /blank/)
@@ -52,7 +52,7 @@
     it 'returns the first matching error when there are errors' do
       define_model(:Example, :attr => :string) do
         validates :attr, :presence => true,
-          :format => { :with => 'abc' }
+          :format => { :with => /abc/ }
       end
       positive_error_description = described_class.new(Example.new, :attr, '', nil)
       positive_error_description.matched_error.should == "can't be blank"
@@ -74,7 +74,7 @@
       validates :attr, :presence => true
     end
     positive_error_description = described_class.new(Example.new, :attr, '', nil)
-    positive_error_description.matches?.should be_false
+    positive_error_description.matches?.should be_true
   end
 
   it 'returns false when there is no matched error' do