Support resource groupings for prefixed APIs

The fact that an API has a prefix (e.g., /api) should not affect the
way resources are grouped for documentation purposes.  This patch
updates the hardcoded single level of resource grouping to ignore the
prefix (which available as part of the route object).

Author: aew

lib/grape-swagger.rb

@@ -13,7 +13,7 @@ def add_swagger_documentation(options={})
 
         @combined_routes = {}
         routes.each do |route|
-          resource = route.route_path.match('\/([\w|-]*?)[\.\/\(]').captures.first
+          resource = route.route_path.split(route.route_prefix).last.match('\/([\w|-]*?)[\.\/\(]').captures.first
           next if resource.empty?
           resource.downcase!
           @combined_routes[resource] ||= []

spec/non_default_api_spec.rb

@@ -257,7 +257,7 @@ def app; SimpleApiWithMarkdown end
     end
   end
 
-  context "versioned API" do
+  context "prefixed and versioned API" do
     before :all do
       class VersionedMountedApi < Grape::API
         prefix 'api'
@@ -278,7 +278,8 @@ class SimpleApiWithVersion < Grape::API
     def app; SimpleApiWithVersion end
 
     it "parses version and places it in the path" do
-      get '/swagger_doc/api.json'
+      get '/swagger_doc/something.json'
+
       JSON.parse(last_response.body)["apis"].each do |api|
         api["path"].should start_with "/api/v1/"
       end