Fix Enum JSON/XML Serialization for Round-Trip Compatibility

Author: codeconsole

grails-converters/src/main/groovy/grails/converters/JSON.java

@@ -185,6 +185,9 @@ else if (o instanceof CharSequence) {
             else if (o instanceof Class<?>) {
                 writer.value(((Class<?>) o).getName());
             }
+            else if (o instanceof Enum) {
+                writer.value(((Enum<?>) o).name());
+            }
             else if (o instanceof Number) {
                 writer.value((Number) o);
             } else if (o instanceof Boolean) {

grails-converters/src/main/groovy/grails/converters/XML.java

@@ -171,6 +171,9 @@ public void convertAnother(Object o) throws ConverterException {
             else if (o instanceof Class<?>) {
                 writer.characters(((Class<?>) o).getName());
             }
+            else if (o instanceof Enum) {
+                writer.characters(((Enum<?>) o).name());
+            }
             else if ((o.getClass().isPrimitive() && !o.getClass().equals(byte[].class)) ||
                     o instanceof Number || o instanceof Boolean) {
                 writer.characters(String.valueOf(o));

grails-converters/src/main/groovy/org/grails/web/converters/configuration/ConvertersConfigurationInitializer.java

@@ -95,7 +95,6 @@ private void initJSONConfiguration() {
         marshallers.add(new org.grails.web.converters.marshaller.json.ByteArrayMarshaller());
         marshallers.add(new org.grails.web.converters.marshaller.json.CollectionMarshaller());
         marshallers.add(new org.grails.web.converters.marshaller.json.MapMarshaller());
-        marshallers.add(new org.grails.web.converters.marshaller.json.EnumMarshaller());
         marshallers.add(new org.grails.web.converters.marshaller.ProxyUnwrappingMarshaller<>());
 
         Config grailsConfig = getGrailsConfig();
@@ -177,7 +176,6 @@ private void initXMLConfiguration() {
         marshallers.add(new org.grails.web.converters.marshaller.xml.ArrayMarshaller());
         marshallers.add(new org.grails.web.converters.marshaller.xml.CollectionMarshaller());
         marshallers.add(new org.grails.web.converters.marshaller.xml.MapMarshaller());
-        marshallers.add(new org.grails.web.converters.marshaller.xml.EnumMarshaller());
         marshallers.add(new org.grails.web.converters.marshaller.xml.DateMarshaller());
         marshallers.add(new ProxyUnwrappingMarshaller<>());
         marshallers.add(new org.grails.web.converters.marshaller.xml.ToStringBeanMarshaller());

grails-converters/src/main/groovy/org/grails/web/converters/marshaller/json/EnumMarshaller.java

@@ -94,13 +94,14 @@ class JSONConverterTests extends Specification implements ControllerUnitTest<JSO
         when:
         def enumInstance = Role.HEAD
         params.e = enumInstance
-        controller.testEnum()
+        controller.testEnumInMap()
+        def jsonString = response.contentAsString
         def json = response.json
 
         then:
-        json.enumType == "org.grails.web.converters.Role"
-        json.name == "HEAD"
-        json.size() == 2
+        json.size() == 1
+        jsonString == '{"value":"HEAD"}'
+        json.value == "HEAD"
     }
 
     // GRAILS-11513
@@ -196,6 +197,10 @@ class JSONConverterController {
        render params.e as JSON
    }
 
+   def testEnumInMap = {
+       render([value: params.e] as JSON)
+   }
+
     def testNullValues = {
         def descriptors = [:]
         descriptors.put(null,null)