Improvements to handling/validation of JsonCreator with Enum types

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java

@@ -1482,10 +1482,13 @@ public JsonDeserializer<?> createEnumDeserializer(DeserializationContext ctxt,
                     }
                     Class<?> returnType = factory.getRawReturnType();
                     // usually should be class, but may be just plain Enum<?> (for Enum.valueOf()?)
-                    if (returnType.isAssignableFrom(enumClass)) {
-                        deser = EnumDeserializer.deserializerForCreator(config, enumClass, factory, valueInstantiator, creatorProps);
-                        break;
+                    if (!returnType.isAssignableFrom(enumClass)) {
+                        ctxt.reportBadDefinition(type, String.format(
+"Invalid `@JsonCreator` annotated Enum factory method [%s]: needs to return compatible type",
+factory.toString()));
                     }
+                    deser = EnumDeserializer.deserializerForCreator(config, enumClass, factory, valueInstantiator, creatorProps);
+                    break;
                 }
             }
 
@@ -2219,7 +2222,7 @@ protected boolean _hasCreatorAnnotation(DeserializationContext ctxt,
         }
         return false;
     }
-    
+
     /*
     /**********************************************************
     /* Deprecated helper methods

src/main/java/com/fasterxml/jackson/databind/deser/std/EnumDeserializer.java

@@ -168,7 +168,7 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
     public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
     {
         JsonToken curr = p.currentToken();
-        
+
         // Usually should just get string value:
         if (curr == JsonToken.VALUE_STRING || curr == JsonToken.FIELD_NAME) {
             CompactStringObjectMap lookup = ctxt.isEnabled(DeserializationFeature.READ_ENUMS_USING_TO_STRING)

src/main/java/com/fasterxml/jackson/databind/deser/std/FactoryBasedEnumDeserializer.java

@@ -106,22 +106,37 @@ public Boolean supportsUpdate(DeserializationConfig config) {
     @Override
     public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
     {
-        Object value = null;
+System.err.println("FactoryBasedEnumDeserializer.deserialize... deser == "+_deser);
+
+        Object value;
         if (_deser != null) {
             value = _deser.deserialize(p, ctxt);
         } else if (_hasArgs) {
             JsonToken curr = p.currentToken();
-            //There can be a JSON object passed for deserializing an Enum,
-            //the below case handles it.
-            if (curr == JsonToken.VALUE_STRING || curr == JsonToken.FIELD_NAME) {
-                value = p.getText();
-            } else if ((_creatorProps != null) && p.isExpectedStartObjectToken()) {
+
+            // 30-Mar-2020, tatu: For properties-based one, MUST get JSON Object (before
+            //   2.11, was just assuming match)
+            if (_creatorProps != null) {
+                if (!p.isExpectedStartObjectToken()) {
+                    final JavaType targetType = getValueType(ctxt);
+                    ctxt.reportInputMismatch(targetType,
+"Input mismatch reading Enum %s: properties-based `@JsonCreator` (%s) expects JSON Object (JsonToken.START_OBJECT), got JsonToken.%s",
+ClassUtil.getTypeDescription(targetType), _factory, p.currentToken());
+                }
                 if (_propCreator == null) {
                     _propCreator = PropertyBasedCreator.construct(ctxt, _valueInstantiator, _creatorProps,
                             ctxt.isEnabled(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES));
                 }
                 p.nextToken();
                 return deserializeEnumUsingPropertyBased(p, ctxt, _propCreator);
+            }
+
+            //There can be a JSON object passed for deserializing an Enum,
+            //the below case handles it.
+            if (curr == JsonToken.VALUE_STRING || curr == JsonToken.FIELD_NAME) {
+                value = p.getText();
+            } else if (curr == JsonToken.VALUE_NUMBER_INT) {
+                value = p.getNumberValue();
             } else {
                 value = p.getValueAsString();
             }