Fixes exception when duplicate parameter names are given in path

lib/http_router.rb

@@ -24,6 +24,8 @@ class HttpRouter
   TooManyParametersException  = Class.new(RuntimeError)
   # Raised when there are left over options
   LeftOverOptions             = Class.new(RuntimeError)
+  # Raised when there are duplicate param names specified in a Path
+  AmbiguousVariableException  = Class.new(RuntimeError)
 
   RecognizeResponse           = Struct.new(:matches, :acceptable_methods)
 

lib/http_router/node/path.rb

@@ -6,7 +6,8 @@ class Path < Node
       def initialize(router, parent, route, path, param_names = [])
         @route, @path, @param_names, @dynamic = route, path, param_names, !param_names.empty?
         @route.add_path(self)
-        raise AmbiguousVariableException, "You have duplicate variable name present: #{param_names.join(', ')}" if param_names.uniq.size != param_names.size
+
+        raise AmbiguousVariableException, "You have duplicate variable names present: #{duplicates.join(', ')}" if param_names.uniq.size != param_names.size
         super router, parent
         router.uncompile
       end
@@ -46,6 +47,10 @@ def usable?(other)
       def inspect_label
         "Path: #{path.inspect} for route #{route.name || 'unnamed route'} to #{route.dest.inspect}"
       end
+
+      def duplicates
+        param_names.group_by { |e| e }.select { |k, v| v.size > 1 }.map(&:first)
+      end
     end
   end
 end

test/test_misc.rb

@@ -87,6 +87,12 @@ def test_too_many_params
     assert_raises(HttpRouter::InvalidRouteException) { r.path(:route) }
   end
 
+  def test_ambigiuous_parameters_in_route
+    r = router
+    r.add("/abc/:id/test/:id", :name => :route).default_destination
+    assert_raises(HttpRouter::AmbiguousVariableException) { r.path(:route, :id => 'fail') }
+  end
+
   def test_public_interface
     methods = HttpRouter.public_instance_methods.map(&:to_sym)
     assert methods.include?(:url_mount)