Make PropertyNamingStrategy not affect Enums (#4414)

Author: JooHyukKim

release-notes/CREDITS-2.x

@@ -1730,6 +1730,11 @@ Jan Pachol (janpacho@github)
   (2.16.0)
 
 Pieter Dirk Soels (Badbond@github)
- * Reprted #4302: Problem deserializing some type of Enums when using
+ * Reported #4302: Problem deserializing some type of Enums when using
   `PropertyNamingStrategy`
   (2.16.2)
+
+Stephane Bailliez (sbailliez@github)
+ * Reported #4409: Deserialization of enums with name defined with different cases
+   leads to `InvalidDefinitionException`: Multiple fields representing property
+  (2.16.2)

release-notes/VERSION-2.x

@@ -22,6 +22,10 @@ Project: jackson-databind
 #4355: Jackson 2.16 fails attempting to obtain `ObjectWriter` for an `Enum` of which
   some value returns null from `toString()`
  (reported by @YutaHiguchi-bsn)
+#4409: Deserialization of enums with name defined with different cases leads to
+  `InvalidDefinitionException`: Multiple fields representing property
+ (reported by Stephane B)
+ (fix contributed by Joo-Hyuk K)
 
 2.16.1 (24-Dec-2023)
 

src/main/java/com/fasterxml/jackson/databind/introspect/POJOPropertiesCollector.java

@@ -6,6 +6,7 @@
 import com.fasterxml.jackson.annotation.JacksonInject;
 import com.fasterxml.jackson.annotation.JsonCreator;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.cfg.HandlerInstantiator;
 import com.fasterxml.jackson.databind.cfg.MapperConfig;
@@ -1123,6 +1124,10 @@ protected void _renameProperties(Map<String, POJOPropertyBuilder> props)
     protected void _renameUsing(Map<String, POJOPropertyBuilder> propMap,
             PropertyNamingStrategy naming)
     {
+        // [databind#4409]: Need to skip renaming for Enums, unless Enums are handled as OBJECT format
+        if (_type.isEnumType() && (_findFormatShape() != JsonFormat.Shape.OBJECT)) {
+            return;
+        }
         POJOPropertyBuilder[] props = propMap.values().toArray(new POJOPropertyBuilder[propMap.size()]);
         propMap.clear();
         for (POJOPropertyBuilder prop : props) {
@@ -1171,6 +1176,29 @@ protected void _renameUsing(Map<String, POJOPropertyBuilder> propMap,
         }
     }
 
+    /**
+     * Helper method called to check if given property should be renamed using {@link PropertyNamingStrategies}.
+     *<p>
+     * NOTE: copied+simplified version of {@code BasicBeanDescription.findExpectedFormat()}.
+     *
+     * @since 2.16.2
+     */
+    private JsonFormat.Shape _findFormatShape()
+    {
+        JsonFormat.Shape shape = null;
+        JsonFormat.Value format = _annotationIntrospector.findFormat(_classDef);
+        if (format != null) {
+            shape = format.getShape();
+        }
+        JsonFormat.Value defFormat = _config.getDefaultPropertyFormat(_classDef.getRawType());
+        if (defFormat != null) {
+            if (shape == null) {
+                shape = defFormat.getShape();
+            }
+        }
+        return shape;
+    }
+
     protected void _renameWithWrappers(Map<String, POJOPropertyBuilder> props)
     {
         // 11-Sep-2012, tatu: To support 'MapperFeature.USE_WRAPPER_NAME_AS_PROPERTY_NAME',

src/main/java/com/fasterxml/jackson/databind/introspect/POJOPropertyBuilder.java

@@ -3,10 +3,7 @@
 import java.util.*;
 import java.util.stream.Collectors;
 
-import com.fasterxml.jackson.annotation.JsonInclude;
-import com.fasterxml.jackson.annotation.JsonProperty;
-import com.fasterxml.jackson.annotation.JsonSetter;
-import com.fasterxml.jackson.annotation.Nulls;
+import com.fasterxml.jackson.annotation.*;
 
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.cfg.ConfigOverride;

src/test/java/com/fasterxml/jackson/databind/deser/enums/EnumWithNamingStrategy4409Test.java

@@ -0,0 +1,38 @@
+package com.fasterxml.jackson.databind.deser.enums;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import static com.fasterxml.jackson.databind.BaseMapTest.jsonMapperBuilder;
+
+// [databind#4409]: PropertyNamingStrategy should not affect to Enums
+class EnumWithNamingStrategy4409Test {
+
+    enum ColorMode {
+        RGB,
+        RGBa,
+        RGBA
+    }
+
+    static class Bug {
+        public ColorMode colorMode;
+    }
+
+    @Test
+    public void testEnumAndPropertyNamingStrategy() throws Exception {
+        ObjectMapper mapper = jsonMapperBuilder()
+            .propertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE)
+            .disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+            .build();
+
+        Bug bug = mapper.readValue("{ \"color_mode\": \"RGBa\"}", Bug.class);
+
+        // fails
+        assertEquals(ColorMode.RGBa, bug.colorMode);
+    }
+}