Add support for Rack::Multipart::UploadedFile and don't care about parameter presence in the validation.

Author: tim-vandecasteele

lib/grape/validations/coerce.rb

@@ -16,6 +16,7 @@ def validate_param!(attr_name, params)
         end
       end
 
+      class InvalidValue; end
     private
 
       def _valid_array_type?(type, values)
@@ -27,8 +28,11 @@ def _valid_array_type?(type, values)
       def _valid_single_type?(klass, val)
         if klass == Virtus::Attribute::Boolean
           val.is_a?(TrueClass) || val.is_a?(FalseClass)
+        elsif klass == Rack::Multipart::UploadedFile
+          val.is_a?(Hashie::Mash) && val.key?(:tempfile)
         else
-          val.is_a?(klass)
+          # allow nil, to ignore when a parameter is absent
+          val.nil? || val.is_a?(klass)
         end
       end
 
@@ -47,7 +51,7 @@ def coerce_value(type, val)
       # not the prettiest but some invalid coercion can currently trigger
       # errors in Virtus (see coerce_spec.rb)
       rescue
-        nil
+        InvalidValue.new
       end
 
     end

spec/grape/validations/coerce_spec.rb

@@ -32,6 +32,7 @@ class API < Grape::API
 
         params do
           requires :int, :coerce => Integer
+          optional :int2, :coerce => Integer
           optional :arr, :coerce => Array[Integer]
           optional :bool, :coerce => Array[Boolean]
         end
@@ -76,12 +77,12 @@ def app
   end
 
   it 'should coerce inputs' do
-    get('/coerce', :int => "43")
+    get('/coerce', :int => "43", :int2 => "42")
     last_response.status.should == 200
     ret = MultiJson.load(last_response.body)
     ret["int"].should == "Fixnum"
-    
-    get('/coerce', :int => "40", :arr => ["1","20","3"], :bool => [1, 0])
+
+    get('/coerce', :int => "40", :int2 => "42", :arr => ["1","20","3"], :bool => [1, 0])
     # last_response.body.should == ""
     last_response.status.should == 200
     ret = MultiJson.load(last_response.body)
@@ -90,4 +91,8 @@ def app
     ret["bool"].should == true
   end
 
+  it 'should not return an error when an optional parameter is nil' do
+    get('/coerce', :int => "40")
+    last_response.status.should == 200
+  end
 end