Add SetTheFlashMatcher#[] to specify flash type

lib/shoulda/matchers/action_controller/set_the_flash_matcher.rb

@@ -10,6 +10,7 @@ module ActionController # :nodoc:
       #   it { should set_the_flash }
       #   it { should set_the_flash.to("Thank you for placing this order.") }
       #   it { should set_the_flash.to(/created/i) }
+      #   it { should set_the_flash[:alert].to("Password doesn't match") }
       #   it { should set_the_flash.to(/logged in/i).now }
       #   it { should_not set_the_flash }
       def set_the_flash
@@ -28,6 +29,11 @@ def now
           self
         end
 
+        def [](key)
+          @key = key
+          self
+        end
+
         def matches?(controller)
           @controller = controller
           sets_the_flash? && string_value_matches? && regexp_value_matches?
@@ -52,17 +58,25 @@ def negative_failure_message
         private
 
         def sets_the_flash?
-          !flash.blank?
+          flash_values.any?
         end
 
         def string_value_matches?
           return true unless String === @value
-          flash.to_hash.values.any? {|value| value == @value }
+          flash_values.any? {|value| value == @value }
         end
 
         def regexp_value_matches?
           return true unless Regexp === @value
-          flash.to_hash.values.any? {|value| value =~ @value }
+          flash_values.any? {|value| value =~ @value }
+        end
+
+        def flash_values
+          if @key
+            [flash.to_hash[@key]]
+          else
+            flash.to_hash.values
+          end
         end
 
         def flash
@@ -74,7 +88,7 @@ def flash
         end
 
         def expectation
-          expectation = "the flash#{".now" if @now} to be set"
+          expectation = "the flash#{".now" if @now}#{":[%s]" % @key if @key} to be set"
           expectation << " to #{@value.inspect}" unless @value.nil?
           expectation << ", but #{flash_description}"
           expectation

spec/shoulda/action_controller/set_the_flash_matcher_spec.rb

@@ -58,6 +58,44 @@
     end
   end
 
+  context "a controller that sets a flash message of notice and alert" do
+    before do
+      @controller = build_response do
+        flash[:notice] = 'value'
+        flash[:alert]  = 'other'
+      end
+    end
+
+    it "should accept flash message of notice" do
+      @controller.should set_the_flash[:notice]
+    end
+
+    it "should accept flash message of alert" do
+      @controller.should set_the_flash[:notice]
+    end
+
+    it "should reject flash message of warning" do
+      @controller.should_not set_the_flash[:warning]
+    end
+
+    it "should accept exact flash message of notice" do
+      @controller.should set_the_flash[:notice].to('value')
+    end
+
+    it "should accept setting a matched flash message of notice" do
+      @controller.should set_the_flash[:notice].to(/value/)
+    end
+
+    it "should reject setting a different flash message of notice" do
+      @controller.should_not set_the_flash[:notice].to('other')
+    end
+
+    it "should reject setting a different pattern" do
+      @controller.should_not set_the_flash[:notice].to(/other/)
+    end
+
+  end
+
   context "a controller that sets multiple flash messages" do
     before do
       @controller = build_response {