Fix Hash params renaming

CHANGELOG.md

@@ -10,6 +10,7 @@
 * [#1893](https://github.com/ruby-grape/grape/pull/1893): Allows `Grape::API` to behave like a Rack::app in some instances where it was misbehaving - [@myxoh](https://github.com/myxoh).
 * [#1898](https://github.com/ruby-grape/grape/pull/1898): Refactor `ValidatorFactory` to improve memory allocation - [@Bhacaz](https://github.com/Bhacaz).
 * [#1900](https://github.com/ruby-grape/grape/pull/1900): Define boolean for `Grape::Api::Instance` - [@Bhacaz](https://github.com/Bhacaz).
+* [#1903](https://github.com/ruby-grape/grape/pull/1903): Allow nested params renaming (Hash/Array) - [@bikolya](https://github.com/bikolya).
 
 ### 1.2.4 (2019/06/13)
 

lib/grape/validations/params_scope.rb

@@ -186,7 +186,7 @@ def new_scope(attrs, optional = false, &block)
 
  self.class.new(
  api: @api,
- element: attrs.first,
+ element: attrs[1][:as] || attrs.first,
  parent: self,
  optional: optional,
  type: type || Array,

spec/grape/validations/params_scope_spec.rb

@@ -165,6 +165,19 @@ def initialize(value)
 
  expect(last_response.status).to eq(200)
  end
+
+ it do
+ subject.params do
+ requires :foo, as: :baz, type: Hash do
+ requires :bar, as: :qux
+ end
+ end
+ subject.get('/nested-renaming') { declared(params).to_json }
+ get '/nested-renaming', foo: { bar: 'any' }
+
+ expect(last_response.status).to eq(200)
+ expect(last_response.body).to eq('{"baz":{"qux":"any"}}')
+ end
  end
 
  context 'array without coerce type explicitly given' do