Fix: declared params bug with nested namespaces (#1564)

Author: bmarini

CHANGELOG.md

@@ -10,6 +10,8 @@
 * [#1559](https://github.com/ruby-grape/grape/pull/1559): You can once again pass `nil` to optional attributes with `values` validation set - [@ghiculescu](https://github.com/ghiculescu).
 * [#1562](https://github.com/ruby-grape/grape/pull/1562): Fix rainbow gem installation failure above ruby 2.3.3 on travis-ci - [@brucehsu](https://github.com/brucehsu).
 * [#1561](https://github.com/ruby-grape/grape/pull/1561): Fix performance issue introduced by duplicated calls in StackableValue#[] - [@brucehsu](https://github.com/brucehsu).
+* [#1564](https://github.com/ruby-grape/grape/pull/1564): Fix declared params bug with nested namespaces - [@bmarini](https://github.com/bmarini).
+* Your contribution here.
 
 ### 0.19.1 (1/9/2017)
 

lib/grape/dsl/inside_route.rb

@@ -29,8 +29,11 @@ module PostBeforeFilter
         def declared(params, options = {}, declared_params = nil)
           options = options.reverse_merge(include_missing: true, include_parent_namespaces: true)
 
-          all_declared_params = route_setting(:declared_params)
-          current_namespace_declared_params = route_setting(:saved_declared_params).last
+          # Declared params including parent namespaces
+          all_declared_params = route_setting(:saved_declared_params).flatten | Array(route_setting(:declared_params))
+
+          # Declared params at current namespace
+          current_namespace_declared_params = route_setting(:saved_declared_params).last & Array(route_setting(:declared_params))
 
           declared_params ||= options[:include_parent_namespaces] ? all_declared_params : current_namespace_declared_params
 

spec/grape/endpoint_spec.rb

@@ -583,6 +583,39 @@ def app
     end
   end
 
+  describe '#declared; mixed nesting' do
+    before do
+      subject.format :json
+      subject.resource :users do
+        route_param :id, type: Integer, desc: 'ID desc' do
+          # Adding this causes route_setting(:declared_params) to be nil for the
+          # get block in namespace 'foo' below
+          get do
+          end
+
+          namespace 'foo' do
+            get do
+              {
+                params: params,
+                declared_params: declared(params),
+                declared_params_no_parent: declared(params, include_parent_namespaces: false)
+              }
+            end
+          end
+        end
+      end
+    end
+
+    it 'can access parent route_param' do
+      get '/users/123/foo', bar: 'bar'
+      expect(last_response.status).to eq 200
+      json = JSON.parse(last_response.body, symbolize_names: true)
+
+      expect(json[:declared_params][:id]).to eq 123
+      expect(json[:declared_params_no_parent][:id]).to eq nil
+    end
+  end
+
   describe '#declared; with multiple route_param' do
     before do
       mounted = Class.new(Grape::API)