Fix documentation of false/nil default parameter values (#839)

* Fix documentation of false/nil default values

* Update CHANGELOG

Author: magni-

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 #### Fixes
 
+* #[#839](https://github.com/ruby-grape/grape-swagger/pull/839): Fixes documentation of `false` or `nil` default parameter values - [@magni-](https://github.com/magni-)
 * Your contribution here.
 
 

lib/grape-swagger/doc_methods/parse_params.rb

@@ -51,7 +51,7 @@ def document_range_values(settings)
         end
 
         def document_default_value(settings)
-          @parsed_param[:default] = settings[:default] if settings[:default].present?
+          @parsed_param[:default] = settings[:default] if settings.key?(:default)
         end
 
         def document_type_and_format(settings, data_type)

spec/swagger_v2/boolean_params_spec.rb

@@ -9,6 +9,7 @@ def app
 
       params do
         requires :a_boolean, type: Grape::API::Boolean
+        optional :another_boolean, type: Grape::API::Boolean, default: false
       end
       post :splines do
         { message: 'hi' }
@@ -27,7 +28,8 @@ def app
 
   it 'converts boolean types' do
     expect(subject).to eq [
-      { 'in' => 'formData', 'name' => 'a_boolean', 'type' => 'boolean', 'required' => true }
+      { 'in' => 'formData', 'name' => 'a_boolean', 'type' => 'boolean', 'required' => true },
+      { 'in' => 'formData', 'name' => 'another_boolean', 'type' => 'boolean', 'required' => false, 'default' => false }
     ]
   end
 end