Correctly validate 204 responses (#133)

* Do not raise error when body is empty and nil content type

Empty response bodies (204 responses for instance) should not have a
content type and therefore an error should not be raised in strict mode
when the response body is empty and the content type is nil as this
behavior is expected.

* Return true instead of nil when validation passes

As mentioned in #101 it makes more sense to return true from this method
when validation passes instead of nil.

---------

Co-authored-by: Tristan O'Neil <tristan.oneil@calendly.com>

Author: tristanoneil

lib/openapi_parser/schemas/response.rb

@@ -21,9 +21,11 @@ def validate(response_body, response_validate_options)
 
       media_type = select_media_type(response_body.content_type)
       unless media_type
-        raise ::OpenAPIParser::NotExistContentTypeDefinition, object_reference if response_validate_options.strict
+        if response_validate_options.strict && response_body_not_blank(response_body)
+          raise ::OpenAPIParser::NotExistContentTypeDefinition, object_reference
+        end
 
-        return nil
+        return true
       end
 
       options = ::OpenAPIParser::SchemaValidator::Options.new # response validator not support any options
@@ -39,6 +41,11 @@ def select_media_type(content_type)
 
     private
 
+      # @param [OpenAPIParser::RequestOperation::ValidatableResponseBody]
+      def response_body_not_blank(response_body)
+        !(response_body.response_data.nil? || response_body.response_data.empty?)
+      end
+
       # @param [Hash] response_headers
       def validate_header(response_headers)
         return unless headers

spec/openapi_parser/request_operation_spec.rb

@@ -67,7 +67,7 @@
       let(:content_type) { nil }
       let(:data) { { 'string' => 1 } }
 
-      it { expect(subject).to eq nil }
+      it { expect(subject).to eq true }
     end
 
     context 'with header' do
@@ -155,6 +155,7 @@
 
           context 'not exist content type' do
             let(:content_type) { 'application/xml' }
+            let(:data) { '<something></something>' }
 
             it do
               expect { subject }.to raise_error do |e|
@@ -163,6 +164,18 @@
               end
             end
           end
+
+          context 'with nil content type when the response body is blank' do
+            let(:status_code) { 204 }
+            let(:content_type) { nil }
+            let(:data) { '' }
+            let(:http_method) { :get }
+
+            it do
+              expect { subject }.to_not raise_error
+              expect(subject).to eq true
+            end
+          end
         end
 
         context 'default parameter' do
@@ -189,6 +202,7 @@
 
           context 'not exist content type' do
             let(:content_type) { 'application/xml' }
+            let(:data) { '<something></something>' }
 
             it do
               expect { subject }.to raise_error do |e|