Fix rendering of responses with empty bodies (#3674)

layouts/partials/openapi/render-responses.html

@@ -36,15 +36,13 @@
 </table>
 
 {{ range $code, $response := $responses }}
-
     {{ if $response.schema }}
 
+<h3>{{$code}} response</h3>
+
         {{ $schema := partial "json-schema/resolve-refs" (dict "schema" $response.schema "path" $path) }}
         {{ $schema := partial "json-schema/resolve-allof" $schema }}
 
-        {{ if or $schema.properties (eq $schema.type "array") }}
-<h3>{{ $code}} response</h3>
-
         {{/*
           All this is to work out how to express the content of the response
           in the case where it is an array.
@@ -67,12 +65,22 @@
 <p>Array of <code>{{ $type_of }}</code>.</p>
         {{ end }}
 
+
+        {{/*
+          render object tables for any objects referenced in the
+          response. (This will be a no-op for response types which aren't
+          objects or arrays.)
+        */}}
         {{ $additional_types := partial "json-schema/resolve-additional-types" $schema }}
         {{ $additional_types = uniq $additional_types }}
         {{ range $additional_types }}
             {{ partial "openapi/render-object-table" (dict "caption" .title "properties" .properties "required" .required) }}
         {{ end }}
 
+        {{/*
+           render an example. currently this is only supported for arrays and objects.
+        */}}
+        {{ if or (eq $schema.type "object") (eq $schema.type "array") }}
             {{ $example := partial "json-schema/resolve-example" $schema }}
             {{ if $response.examples }}
                 {{ $example = partial "json-schema/resolve-refs" (dict "schema" $response.examples "path" $path) }}