Enable DeserializationFeature.READ_ENUMS_USING_TO_STRING by default (3.0) (#4566)

Author: JooHyukKim

release-notes/VERSION

@@ -58,6 +58,8 @@ Versions: 3.x (for earlier see VERSION-2.x)
 #4160: Deprecate `DefaultTyping.EVERYTHING` in `2.x` and remove in `3.0`
 #4381: Prevent construction of `null`-valued `JsonNode`s (like `TextNode`)
 #4552: Change `MapperFeature.ALLOW_FINAL_FIELDS_AS_MUTATORS` default to `false` for 3.0
+#4566: Enable `DeserializationFeature.READ_ENUMS_USING_TO_STRING` by default (3.0)
+ (contributed by Joo-Hyuk K)
 - Remove `MappingJsonFactory`
 - Add context parameter for `TypeSerializer` contextualization (`forProperty()`)
 - Default for `JsonNodeFeature.STRIP_TRAILING_BIGDECIMAL_ZEROES` changed to `false` for 3.0

src/main/java/tools/jackson/databind/DeserializationFeature.java

@@ -388,17 +388,17 @@ public enum DeserializationFeature implements ConfigFeature
     ACCEPT_FLOAT_AS_INT(true),
 
     /**
-     * Feature that determines standard deserialization mechanism used for
-     * Enum values: if enabled, Enums are assumed to have been serialized  using
-     * return value of <code>Enum.toString()</code>;
-     * if disabled, return value of <code>Enum.name()</code> is assumed to have been used.
+     * Feature that determines the deserialization mechanism used for
+     * Enum values: if enabled, Enums are assumed to have been serialized using
+     * return value of {@code Enum.toString()};
+     * if disabled, return value of {@code Enum.name()} is assumed to have been used.
      *<p>
      * Note: this feature should usually have same value
      * as {@link SerializationFeature#WRITE_ENUMS_USING_TO_STRING}.
      *<p>
-     * Feature is disabled by default.
+     * Feature is enabled by default as of Jackson 3.0 (in 2.x it was disabled).
      */
-    READ_ENUMS_USING_TO_STRING(false),
+    READ_ENUMS_USING_TO_STRING(true),
 
     /**
      * Feature that allows unknown Enum values to be parsed as {@code null} values.

src/test/java/tools/jackson/databind/deser/creators/EnumCreatorTest.java

@@ -343,7 +343,7 @@ public void testNoArgEnumCreator() throws Exception
     @Test
     public void testEnumCreators1291() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
+        ObjectMapper mapper = jsonMapperBuilder().disable(DeserializationFeature.READ_ENUMS_USING_TO_STRING).build();
         String json = mapper.writeValueAsString(Enum1291.V2);
         Enum1291 result = mapper.readValue(json, Enum1291.class);
         assertSame(Enum1291.V2, result);

src/test/java/tools/jackson/databind/deser/enums/EnumDefaultReadTest.java

@@ -91,7 +91,9 @@ enum MixinOverloadedDefault {
     /**********************************************************
      */
 
-    private final ObjectMapper MAPPER = newJsonMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .disable(DeserializationFeature.READ_ENUMS_USING_TO_STRING)
+            .build();
 
     @Test
     public void testWithoutCustomFeatures() throws Exception

src/test/java/tools/jackson/databind/deser/enums/EnumDeserFromIntJsonValueTest.java

@@ -8,7 +8,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import static tools.jackson.databind.testutil.DatabindTestUtil.newJsonMapper;
+import static tools.jackson.databind.testutil.DatabindTestUtil.jsonMapperBuilder;
 
 public class EnumDeserFromIntJsonValueTest
 {
@@ -44,7 +44,8 @@ enum Bean1850LongField {
         Bean1850LongField(long x) { this.x = x; }
     }
 
-    private final ObjectMapper MAPPER = newJsonMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .disable(DeserializationFeature.READ_ENUMS_USING_TO_STRING).build();
 
     // [databind#1850] pass tests
 
@@ -60,6 +61,7 @@ public void testEnumFromInt1850Method() throws Exception
     public void testEnumFromInt1850Field() throws Exception
     {
         String json = MAPPER.writeValueAsString(Bean1850IntField.A);
+
         Bean1850IntField e2 = MAPPER.readValue(json, Bean1850IntField.class);
         assertEquals(Bean1850IntField.A, e2);
     }

src/test/java/tools/jackson/databind/deser/enums/EnumDeserMixin2787Test.java

@@ -5,6 +5,7 @@
 import com.fasterxml.jackson.annotation.JsonAlias;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.MapperFeature;
 import tools.jackson.databind.ObjectMapper;
 import tools.jackson.databind.exc.InvalidFormatException;
@@ -197,6 +198,7 @@ private ObjectMapper mapperWithMixIn(Class<?> target, Class<?> mixin) {
     }
 
     private JsonMapper.Builder builderWithMixIn(Class<?> target, Class<?> mixin) {
-        return JsonMapper.builder().addMixIn(target, mixin);
+        return JsonMapper.builder().disable(DeserializationFeature.READ_ENUMS_USING_TO_STRING)
+                .addMixIn(target, mixin);
     }
 }

src/test/java/tools/jackson/databind/deser/enums/EnumDeserializationTest.java

@@ -615,6 +615,7 @@ public void testEnumWithJsonPropertyRenameMixin() throws Exception
     public void testDeserWithToString1161() throws Exception
     {
         Enum1161 result = MAPPER.readerFor(Enum1161.class)
+                .without(DeserializationFeature.READ_ENUMS_USING_TO_STRING)
                 .readValue(q("A"));
         assertSame(Enum1161.A, result);
 

src/test/java/tools/jackson/databind/jsontype/deftyping/TestDefaultForObject.java

@@ -106,7 +106,8 @@ public Validity validateBaseType(DatabindContext ctxt, JavaType baseType) {
     /**********************************************************
      */
 
-    private final ObjectMapper MAPPER = newJsonMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .disable(DeserializationFeature.READ_ENUMS_USING_TO_STRING).build();
 
     /**
      * Unit test that verifies that a bean is stored with type information,
@@ -248,6 +249,7 @@ public void testEnumAsObject() throws Exception
 
         // and then with it
         ObjectMapper m = jsonMapperBuilder()
+                .disable(DeserializationFeature.READ_ENUMS_USING_TO_STRING)
                 .activateDefaultTyping(NoCheckSubTypeValidator.instance)
                 .build();
         String json = m.writeValueAsString(input);