Added DateTime/Date/Numeric/Boolean type support allow_blank

Author: u2

CHANGELOG.md

@@ -1,6 +1,7 @@
 Next Release
 ============
 
+* [#916](https://github.com/intridea/grape/pull/916): Added `DateTime/Date/Numeric/Boolean` type support `allow_blank` - [@u2](https://github.com/u2).
 * [#871](https://github.com/intridea/grape/pull/871): Fixed `Grape::Middleware::Base#response` - [@galathius](https://github.com/galathius).
 * [#559](https://github.com/intridea/grape/issues/559): Added support for Rack 1.6.0, which parses requests larger than 128KB - [@myitcv](https://github.com/myitcv).
 * [#876](https://github.com/intridea/grape/pull/876): Call to `declared(params)` now returns a `Hashie::Mash` - [@rodzyn](https://github.com/rodzyn).

lib/grape/validations/validators/coerce.rb

@@ -29,9 +29,12 @@ def _valid_single_type?(klass, val)
         # allow nil, to ignore when a parameter is absent
         return true if val.nil?
         if klass == Virtus::Attribute::Boolean
-          val.is_a?(TrueClass) || val.is_a?(FalseClass)
+          val.is_a?(TrueClass) || val.is_a?(FalseClass) || (val.is_a?(String) && val.empty?)
         elsif klass == Rack::Multipart::UploadedFile
           val.is_a?(Hashie::Mash) && val.key?(:tempfile)
+        elsif [Virtus::Attribute::DateTime, Virtus::Attribute::Date, Virtus::Attribute::Numeric].any?{ |vclass| vclass >= klass }
+          return true if val.is_a?(String) && val.empty?
+          val.is_a?(klass)
         else
           val.is_a?(klass)
         end

spec/grape/validations/validators/allow_blank_spec.rb

@@ -21,13 +21,65 @@ class API < Grape::API
         end
         get '/allow_blank'
 
+        params do
+          requires :val, type: DateTime, allow_blank: true
+        end
+        get '/allow_datetime_blank'
+
+        params do
+          requires :val, type: DateTime, allow_blank: false
+        end
+        get '/disallow_datetime_blank'
+
+        params do
+          requires :val, type: DateTime
+        end
+        get '/default_allow_datetime_blank'
+
+        params do
+          requires :val, type: Date, allow_blank: true
+        end
+        get '/allow_date_blank'
+
+        params do
+          requires :val, type: Integer, allow_blank: true
+        end
+        get '/allow_integer_blank'
+
+        params do
+          requires :val, type: Float, allow_blank: true
+        end
+        get '/allow_float_blank'
+
+        params do
+          requires :val, type: Fixnum, allow_blank: true
+        end
+        get '/allow_fixnum_blank'
+
+        params do
+          requires :val, type: Symbol, allow_blank: true
+        end
+        get '/allow_symbol_blank'
+
+        params do
+          requires :val, type: Boolean, allow_blank: true
+        end
+        get '/allow_boolean_blank'
+
         params do
           optional :user, type: Hash do
             requires :name, allow_blank: false
           end
         end
         get '/disallow_blank_required_param_in_an_optional_group'
 
+        params do
+          optional :user, type: Hash do
+            requires :name, type: Date, allow_blank: true
+          end
+        end
+        get '/allow_blank_date_param_in_an_optional_group'
+
         params do
           optional :user, type: Hash do
             optional :name, allow_blank: false
@@ -75,6 +127,9 @@ def app
     it 'refuses empty string' do
       get '/', name: ''
       expect(last_response.status).to eq(400)
+
+      get '/disallow_datetime_blank', val: ''
+      expect(last_response.status).to eq(400)
     end
 
     it 'refuses only whitespaces' do
@@ -104,6 +159,48 @@ def app
       get '/allow_blank', name: ''
       expect(last_response.status).to eq(200)
     end
+
+    it 'accepts empty input' do
+      get '/default_allow_datetime_blank', val: ''
+      expect(last_response.status).to eq(200)
+    end
+
+    it 'accepts empty when datetime allow_blank' do
+      get '/allow_datetime_blank', val: ''
+      expect(last_response.status).to eq(200)
+    end
+
+    it 'accepts empty when date allow_blank' do
+      get '/allow_date_blank', val: ''
+      expect(last_response.status).to eq(200)
+    end
+
+    context 'allow_blank when Numeric' do
+      it 'accepts empty when integer allow_blank' do
+        get '/allow_integer_blank', val: ''
+        expect(last_response.status).to eq(200)
+      end
+
+      it 'accepts empty when float allow_blank' do
+        get '/allow_float_blank', val: ''
+        expect(last_response.status).to eq(200)
+      end
+
+      it 'accepts empty when fixnum allow_blank' do
+        get '/allow_fixnum_blank', val: ''
+        expect(last_response.status).to eq(200)
+      end
+    end
+
+    it 'accepts empty when symbol allow_blank' do
+      get '/allow_symbol_blank', val: ''
+      expect(last_response.status).to eq(200)
+    end
+
+    it 'accepts empty when boolean allow_blank' do
+      get '/allow_boolean_blank', val: ''
+      expect(last_response.status).to eq(200)
+    end
   end
 
   context 'in an optional group' do
@@ -113,6 +210,11 @@ def app
         expect(last_response.status).to eq(200)
       end
 
+      it 'accepts a nested missing date value' do
+        get '/allow_blank_date_param_in_an_optional_group', user: { name: '' }
+        expect(last_response.status).to eq(200)
+      end
+
       it 'refuses a blank value in an existing group' do
         get '/disallow_blank_required_param_in_an_optional_group', user: { name: '' }
         expect(last_response.status).to eq(400)