Make builder work with frozen strings

lib/hair_trigger/builder.rb

@@ -335,10 +335,11 @@ def maybe_execute(&block)
         block.call(self)
         raise DeclarationError, "trigger group did not define any triggers" if @triggers.empty?
       else
-        @actions = block.call
-        (@actions.is_a?(Hash) ? @actions.values : [@actions]).each do |actions|
-          actions.sub!(/(\s*)\z/, ';\1') if actions && actions !~ /;\s*\z/
-        end
+        @actions =
+          case (actions = block.call)
+          when Hash then actions.map { |key, action| [key, ensure_semicolon(action)] }.to_h
+          else ensure_semicolon(actions)
+          end
       end
       # only the top-most block actually executes
       if !@trigger_group
@@ -350,6 +351,10 @@ def maybe_execute(&block)
       self
     end
 
+    def ensure_semicolon(action)
+      action && action !~ /;\s*\z/ ? action.sub(/(\s*)\z/, ';\1') : action
+    end
+
     def validate_names!
       subtriggers = all_triggers(false)
       named_subtriggers = subtriggers.select{ |t| t.options[:name] }

spec/builder_spec.rb

@@ -34,6 +34,13 @@ def builder(name = nil)
       builder.on(:foos).after(:update){ "FOO " }.generate.
         grep(/FOO;/).size.should eql(1)
     end
+
+    it "should work with frozen strings" do
+      @adapter = MockAdapter.new("mysql")
+      lambda {
+        builder.on(:foos).after(:update){ "FOO".freeze }.generate
+      }.should_not raise_error
+    end
   end
 
   context "comparison" do