fix bug for default value as proc when there is given options values

lib/grape/validations/params_scope.rb

@@ -104,10 +104,12 @@ def validates(attrs, validations)
         default = validations[:default]
         doc_attrs[:default] = default if default
 
+        default = default.call if default.is_a?(Proc)
+
         values = validations[:values]
         doc_attrs[:values] = values if values
 
-        values = (values.is_a?(Proc) ? values.call : values)
+        values = values.call if values.is_a?(Proc)
 
         # default value should be present in values array, if both exist
         if default && values && !values.include?(default)

spec/grape/validations/validators/values_spec.rb

@@ -43,6 +43,20 @@ class API < Grape::API
           { type: params[:type] }
         end
 
+        params do
+          optional :type, values: ValuesModel.values, default: -> { ValuesModel.values.sample }
+        end
+        get '/default_lambda' do
+          { type: params[:type] }
+        end
+
+        params do
+          optional :type, values: -> { ValuesModel.values }, default: -> { ValuesModel.values.sample }
+        end
+        get '/default_and_values_lambda' do
+          { type: params[:type] }
+        end
+
         params do
           requires :type, type: Integer, desc: "An integer", values: [10, 11], default: 10
         end
@@ -123,6 +137,30 @@ def app
     expect(last_response.body).to eq({ error: "type does not have a valid value" }.to_json)
   end
 
+  it 'validates default value from proc' do
+    get("/default_lambda")
+    expect(last_response.status).to eq 200
+  end
+
+  it 'validates default value from proc against values in a proc' do
+    get("/default_and_values_lambda")
+    expect(last_response.status).to eq 200
+  end
+
+  it 'raises IncompatibleOptionValues on an invalid default value from proc' do
+    subject = Class.new(Grape::API)
+    expect {
+      subject.params { optional :type, values: ['valid-type1', 'valid-type2', 'valid-type3'], default: -> { ValuesModel.values.sample + "_invalid" } }
+    }.to raise_error Grape::Exceptions::IncompatibleOptionValues
+  end
+
+  it 'raises IncompatibleOptionValues on an invalid default value from proc validating against values in a proc' do
+    subject = Class.new(Grape::API)
+    expect {
+      subject.params { optional :type, values: -> { ValuesModel.values }, default: -> { ValuesModel.values.sample + "_invalid" } }
+    }.to raise_error Grape::Exceptions::IncompatibleOptionValues
+  end
+
   it 'raises IncompatibleOptionValues on an invalid default value' do
     subject = Class.new(Grape::API)
     expect {