Fix: deeply nested parameters within #declared(params) not included (#1512)

Author: krbs

CHANGELOG.md

@@ -3,6 +3,7 @@ Next Release
 
 * [#1503](https://github.com/ruby-grape/grape/pull/1503): Allow to use regexp validator with arrays - [@akoltun](https://github.com/akoltun).
 * [#1507](https://github.com/ruby-grape/grape/pull/1507): Add group attributes for parameter definitions - [@304](https://github.com/304).
+* [#1512](https://github.com/ruby-grape/grape/pull/1512): Fix for deeply nested params TypeError situation - [@krbs](https://github.com/krbs).
 * Your contribution here.
 
 0.18.0 (10/7/2016)

lib/grape/dsl/parameters.rb

@@ -193,21 +193,24 @@ def declared_param?(param)
 
       alias group requires
 
+      def map_params(params, element)
+        if params.is_a?(Array)
+          params.map do |el|
+            map_params(el, element)
+          end
+        elsif params.is_a?(Hash)
+          params[element] || {}
+        else
+          {}
+        end
+      end
+
       # @param params [Hash] initial hash of parameters
       # @return hash of parameters relevant for the current scope
       # @api private
       def params(params)
         params = @parent.params(params) if @parent
-        if @element
-          params = if params.is_a?(Array)
-                     # used for calculating parent array indices for error messages
-                     params.map { |el| el[@element] || {} }
-                   elsif params.is_a?(Hash)
-                     params[@element] || {}
-                   else
-                     {}
-                   end
-        end
+        params = map_params(params, @element) if @element
         params
       end
     end

spec/grape/validations/params_scope_spec.rb

@@ -585,6 +585,25 @@ def initialize(value)
     expect(JSON.parse(last_response.body)).to eq('bar' => { 'a' => 'x', 'c' => { 'b' => 'yes' } })
   end
 
+  it 'includes deeply nested parameters within #declared(params)' do
+    subject.params do
+      requires :arr1, type: Array do
+        requires :hash1, type: Hash do
+          requires :arr2, type: Array do
+            requires :hash2, type: Hash do
+              requires :something, type: String
+            end
+          end
+        end
+      end
+    end
+    subject.get('/nested_deep') { declared(params).to_json }
+
+    get '/nested_deep', arr1: [{ hash1: { arr2: [{ hash2: { something: 'value' } }] } }]
+    expect(last_response.status).to eq(200)
+    expect(JSON.parse(last_response.body)).to eq('arr1' => [{ 'hash1' => { 'arr2' => [{ 'hash2' => { 'something' => 'value' } }] } }])
+  end
+
   context 'failing fast' do
     context 'when fail_fast is not defined' do
       it 'does not stop validation' do