[Jackson-3] Address #493, disable DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES by default.

release-notes/VERSION

@@ -7,6 +7,8 @@ Versions: 3.x (for earlier see VERSION-2.x)
 
 3.0.0 (not yet released)
 
+#493: Change `DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES` default to `false`
+ (contributed by Joo-Hyuk K)
 #1058: Add a way to pass std and format-specific parser/generator flags during
   parser/generation construction
 #1600: Serializing locale with underscore, not standard hyphen

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

@@ -110,12 +110,12 @@ public enum DeserializationFeature implements ConfigFeature
      * This setting only takes effect after all other handling
      * methods for unknown properties have been tried, and
      * property remains unhandled.
+     * Enabling this feature means that a {@link DatabindException}
+     * will be thrown if an unknown property is encountered.
      *<p>
-     * Feature is enabled by default (meaning that a
-     * {@link DatabindException} will be thrown if an unknown property
-     * is encountered).
+     * Feature is disabled by default as of Jackson 3.0 (in 2.x it was enabled).
      */
-    FAIL_ON_UNKNOWN_PROPERTIES(true),
+    FAIL_ON_UNKNOWN_PROPERTIES(false),
 
     /**
      * Feature that determines whether encountering of JSON null

src/test-jdk17/java/tools/jackson/databind/records/RecordCreatorsTest.java

@@ -43,7 +43,7 @@ public String getValue() {
         public String accessValueForTest() { return value; }
     }
 
-    private final ObjectMapper MAPPER = newJsonMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder().enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
 
     /*
     /**********************************************************************

src/test-jdk17/java/tools/jackson/databind/records/RecordExplicitCreatorsTest.java

@@ -8,6 +8,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import tools.jackson.databind.DatabindException;
+import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.MapperFeature;
 import tools.jackson.databind.ObjectMapper;
 import tools.jackson.databind.exc.InvalidDefinitionException;
@@ -106,6 +107,7 @@ public static RecordWithExplicitFactoryMethod valueOf(String value) {
 
     private final ObjectMapper MAPPER = jsonMapperBuilder()
             .disable(MapperFeature.ALLOW_FINAL_FIELDS_AS_MUTATORS) // So that test cases don't have to assert weird error messages
+            .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
             .build();
 
     /*

src/test/java/tools/jackson/databind/deser/AnySetterTest.java

@@ -301,8 +301,9 @@ public void testSimpleMapImitation() throws Exception
     public void testAnySetterDisable() throws Exception
     {
         try {
-            MAPPER.readValue(a2q("{'value':3}"),
-                    MapImitatorDisabled.class);
+            MAPPER.readerFor(MapImitatorDisabled.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(a2q("{'value':3}"));
             fail("Should not pass");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "Unrecognized property \"value\"");

src/test/java/tools/jackson/databind/deser/IncludeWithDeserTest.java

@@ -125,7 +125,7 @@ public void testSimpleInclude() throws Exception
     @Test
     public void testIncludeIgnoredAndUnrecognizedField() throws Exception
     {
-        ObjectReader r = MAPPER.readerFor(OnlyY.class);
+        ObjectReader r = MAPPER.readerFor(OnlyY.class).with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
 
         // First, fine to get "y" only:
         OnlyY result = r.readValue(a2q("{'x':3, 'y': 4}"));

src/test/java/tools/jackson/databind/deser/SetterlessPropertiesDeserTest.java

@@ -74,7 +74,7 @@ public void testSimpleSetterlessCollectionOk() throws Exception
     @Test
     public void testSimpleSetterlessCollectionFailure() throws Exception
     {
-        ObjectMapper m = new ObjectMapper();
+        ObjectMapper m = jsonMapperBuilder().enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
         assertFalse(m.isEnabled(MapperFeature.USE_GETTERS_AS_SETTERS));
 
         // and now this should fail
@@ -108,6 +108,7 @@ public void testSimpleSetterlessMapFailure() throws Exception
     {
         ObjectMapper m = jsonMapperBuilder()
                 .disable(MapperFeature.USE_GETTERS_AS_SETTERS)
+                .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
                 .build();
         // so this should fail now without a setter
         try {

src/test/java/tools/jackson/databind/deser/builder/BuilderFailTest.java

@@ -8,9 +8,7 @@
 import tools.jackson.databind.exc.UnrecognizedPropertyException;
 
 import static org.junit.jupiter.api.Assertions.fail;
-
-import static tools.jackson.databind.testutil.DatabindTestUtil.a2q;
-import static tools.jackson.databind.testutil.DatabindTestUtil.verifyException;
+import static tools.jackson.databind.testutil.DatabindTestUtil.*;
 
 public class BuilderFailTest
 {
@@ -68,7 +66,8 @@ public ValueClassXY build() {
     /**********************************************************
      */
 
-    private final ObjectMapper MAPPER = new ObjectMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
 
     @Test
     public void testBuilderMethodReturnInvalidType() throws Exception

src/test/java/tools/jackson/databind/deser/builder/BuilderSimpleTest.java

@@ -306,7 +306,8 @@ private Value2354 build() {
     /**********************************************************
      */
 
-    private final ObjectMapper MAPPER = newJsonMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
 
     @Test
     public void testSimple() throws Exception

src/test/java/tools/jackson/databind/deser/creators/AnySetterForCreator562Test.java

@@ -217,8 +217,9 @@ public void testAnySetterViaCreator562Disabled() throws Exception
     {
         // With 3.0 different fail type, message since we do we get parameter name info
         try {
-            MAPPER.readValue(a2q("{'a':'value', 'b':42, 'c': 111}"),
-                PojoWithDisabled.class);
+            MAPPER.readerFor(PojoWithDisabled.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(a2q("{'a':'value', 'b':42, 'c': 111}"));
             fail("Should not pass");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "Unrecognized property \"b\"");

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

@@ -145,8 +145,9 @@ public void test1ArgDefaultsToPropsMultipleCtors() throws Exception
         // 23-May-2024, tatu: Will fail differently with [databind#4515]; default
         //   constructor available, implicit ones ignored
         try {
-            MAPPER_PROPS.readValue(a2q("{'value' : 137 }"),
-                SingleArg2CtorsNotAnnotated.class);
+            MAPPER_PROPS.readerFor(SingleArg2CtorsNotAnnotated.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(a2q("{'value' : 137 }"));
             fail("Should not pass");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "\"value\"");

src/test/java/tools/jackson/databind/deser/creators/CreatorWithRenamedParam4545Test.java

@@ -53,7 +53,9 @@ public void testCreatorWithRename4545() throws Exception
         String jsonPayload = a2q("{ 'key1': 'val1', 'key2': 'val2'}");
 
         try {
-            MAPPER.readValue(jsonPayload, Payload4545.class);
+            MAPPER.readerFor(Payload4545.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(jsonPayload);
             fail("Should not pass");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "Unrecognized");

src/test/java/tools/jackson/databind/deser/filter/IgnorePropertyOnDeserTest.java

@@ -7,6 +7,7 @@
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
+import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.ObjectMapper;
 import tools.jackson.databind.exc.UnrecognizedPropertyException;
 
@@ -151,7 +152,9 @@ public void testIgnoreUnknownViaConfigOverride() throws Exception
 
         // First, fail without overrides
         try {
-            MAPPER.readValue(DOC, Point.class);
+            MAPPER.readerFor(Point.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(DOC);
             fail("Should not pass");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "foobar"); // message varies between 2.x and 3.x

src/test/java/tools/jackson/databind/deser/filter/UnknownPropertyDeserTest.java

@@ -162,7 +162,9 @@ static class Bean987 {
     public void testUnknownHandlingDefault() throws Exception
     {
         try {
-            MAPPER.readValue(JSON_UNKNOWN_FIELD, TestBean.class);
+            MAPPER.readerFor(TestBean.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(JSON_UNKNOWN_FIELD);
             fail("Should not pass");
         } catch (UnrecognizedPropertyException jex) {
             verifyException(jex, "Unrecognized property \"foo\"");

src/test/java/tools/jackson/databind/deser/jdk/VoidProperties2675Test.java

@@ -27,10 +27,13 @@ static class VoidBean {
     /**********************************************************************
      */
 
-    private final ObjectMapper VOID_MAPPER = sharedMapper();
+    private final ObjectMapper VOID_MAPPER = jsonMapperBuilder()
+            .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+            .build();
 
     private final ObjectMapper NO_VOID_MAPPER = jsonMapperBuilder()
             .disable(MapperFeature.ALLOW_VOID_VALUED_PROPERTIES)
+            .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
             .build();
 
     @Test

src/test/java/tools/jackson/databind/deser/merge/PropertyMergeTest.java

@@ -226,7 +226,8 @@ public void testBeanAsArrayMerging() throws Exception
         // and finally with extra, failing
         try {
             MAPPER.readerForUpdating(input)
-                .readValue("[9, 8, 14]");
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue("[9, 8, 14]");
             fail("Should not pass");
         } catch (MismatchedInputException e) {
             verifyException(e, "expected at most 2 properties");

src/test/java/tools/jackson/databind/exc/DeserExceptionTypeTest.java

@@ -48,7 +48,9 @@ public void testHandlingOfUnrecognized() throws Exception
     {
         UnrecognizedPropertyException exc = null;
         try {
-            MAPPER.readValue("{\"bar\":3}", Bean.class);
+            MAPPER.readerFor(Bean.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue("{\"bar\":3}");
         } catch (UnrecognizedPropertyException e) {
             exc = e;
         }

src/test/java/tools/jackson/databind/introspect/AccessorNamingForBuilderTest.java

@@ -49,7 +49,8 @@ public ValueClassXY build() {
     public void testAccessorCustomWithMethod() throws Exception
     {
         final String json = a2q("{'x':28,'y':72}");
-        final ObjectMapper vanillaMapper = newJsonMapper();
+        final ObjectMapper vanillaMapper = jsonMapperBuilder()
+                .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
 
         // First: without custom strategy, will fail:
         try {

src/test/java/tools/jackson/databind/introspect/TestInferredMutators.java

@@ -2,6 +2,7 @@
 
 import org.junit.jupiter.api.Test;
 
+import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.MapperFeature;
 import tools.jackson.databind.ObjectMapper;
 import tools.jackson.databind.exc.UnrecognizedPropertyException;
@@ -35,6 +36,7 @@ public static class FixedPoint {
     public void testFinalFieldIgnoral() throws Exception
     {
         ObjectMapper mapper = jsonMapperBuilder()
+                .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
                 .disable(MapperFeature.ALLOW_FINAL_FIELDS_AS_MUTATORS)
                 .build();
         try {
@@ -49,14 +51,15 @@ public void testFinalFieldIgnoral() throws Exception
     public void testDeserializationInference() throws Exception
     {
         final String JSON = "{\"x\":2}";
-        ObjectMapper mapper = new ObjectMapper();
+        ObjectMapper mapper = jsonMapperBuilder().enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
         // First: default case, inference enabled:
         assertTrue(mapper.isEnabled(MapperFeature.INFER_PROPERTY_MUTATORS));
         Point p = mapper.readValue(JSON,  Point.class);
         assertEquals(2, p.x);
 
         // but without it, should fail:
         mapper = jsonMapperBuilder()
+                .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
                 .disable(MapperFeature.INFER_PROPERTY_MUTATORS)
                 .build();
         try {

src/test/java/tools/jackson/databind/introspect/TransientTest.java

@@ -142,8 +142,9 @@ public void testOverridingTransient() throws Exception
     public void testTransientToPrune() throws Exception
     {
         try {
-            TransientToPrune result = MAPPER.readValue("{\"a\":3}",
-                    TransientToPrune.class);
+            TransientToPrune result = MAPPER.readerFor(TransientToPrune.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue("{\"a\":3}");
             fail("Should not pass, got: "+result);
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "Unrecognized", "\"a\"");

src/test/java/tools/jackson/databind/jsontype/TestMultipleTypeNames.java

@@ -7,6 +7,7 @@
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 
+import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.ObjectMapper;
 import tools.jackson.databind.exc.InvalidDefinitionException;
 import tools.jackson.databind.exc.UnrecognizedPropertyException;
@@ -17,7 +18,8 @@
 // Tests for [databind#2761] (and [annotations#171]
 public class TestMultipleTypeNames extends DatabindTestUtil
 {
-    private final ObjectMapper MAPPER = newJsonMapper();
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
 
     // common classes
     static class MultiTypeName { }
@@ -156,7 +158,9 @@ public void testNameAndNames() throws Exception
         // TC 2 : incorrect serialisation
         json = "{\"data\": [{\"type\":\"a\", \"data\": {\"x\": 2.2}}, {\"type\":\"b\", \"data\": {\"y\": 5.3}}, {\"type\":\"c\", \"data\": {\"y\": 9.8}}]}";
         try  {
-            MAPPER.readValue(json, WrapperForNameAndNamesTest.class);
+            MAPPER.readerFor(WrapperForNameAndNamesTest.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(json);
             fail("This serialisation should fail 'coz of x being float");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "Unrecognized property \"data\"");

src/test/java/tools/jackson/databind/misc/CaseInsensitiveDeserTest.java

@@ -133,7 +133,8 @@ public void testCaseInsensitiveDeserialization() throws Exception
         final String JSON = "{\"Value1\" : {\"nAme\" : \"fruit\", \"vALUe\" : \"apple\"}, \"valUE2\" : {\"NAME\" : \"color\", \"value\" : \"red\"}}";
 
         // first, verify default settings which do not accept improper case
-        ObjectMapper mapper = new ObjectMapper();
+        ObjectMapper mapper = jsonMapperBuilder()
+                .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
         assertFalse(mapper.isEnabled(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES));
         try {
             mapper.readValue(JSON, Issue476Bean.class);
@@ -233,8 +234,9 @@ public void testCaseInsensitiveViaClassAnnotation() throws Exception
 
         // and finally, more complicated; should be possible to force sensitivity:
         try {
-            /*CaseSensitiveRoleContainer r =*/ MAPPER.readValue(CONTAINED,
-                    CaseSensitiveRoleContainer.class);
+            /*CaseSensitiveRoleContainer r =*/ jsonMapperBuilder()
+                    .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build()
+                    .readValue(CONTAINED, CaseSensitiveRoleContainer.class);
             fail("Should not pass");
         } catch (UnrecognizedPropertyException e) {
             verifyException(e, "Unrecognized ");

src/test/java/tools/jackson/databind/module/SimpleModuleTest.java

@@ -211,7 +211,7 @@ public void serialize(Test3787Bean value, JsonGenerator gen, SerializerProvider
     @Test
     public void testWithoutModule()
     {
-        ObjectMapper mapper = new ObjectMapper();
+        ObjectMapper mapper = jsonMapperBuilder().enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
         // first: serialization failure:
         try {
             mapper.writeValueAsString(new CustomBean("foo", 3));

src/test/java/tools/jackson/databind/seq/ReadRecoveryTest.java

@@ -32,7 +32,9 @@ static class Bean {
     public void testRootBeans() throws Exception
     {
         final String JSON = a2q("{'a':3} {'x':5}");
-        MappingIterator<Bean> it = MAPPER.readerFor(Bean.class).readValues(JSON);
+        MappingIterator<Bean> it = MAPPER.readerFor(Bean.class)
+                .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                .readValues(JSON);
         // First one should be fine
         assertTrue(it.hasNextValue());
         Bean bean = it.nextValue();
@@ -58,7 +60,9 @@ public void testSimpleRootRecovery() throws Exception
     {
         final String JSON = a2q("{'a':3}{'a':27,'foo':[1,2],'b':{'x':3}}  {'a':1,'b':2} ");
 
-        MappingIterator<Bean> it = MAPPER.readerFor(Bean.class).readValues(JSON);
+        MappingIterator<Bean> it = MAPPER.readerFor(Bean.class)
+                .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                .readValues(JSON);
         Bean bean = it.nextValue();
 
         assertNotNull(bean);
@@ -88,7 +92,9 @@ public void testSimpleArrayRecovery() throws Exception
     {
         final String JSON = a2q("[{'a':3},{'a':27,'foo':[1,2],'b':{'x':3}}  ,{'a':1,'b':2}  ]");
 
-        MappingIterator<Bean> it = MAPPER.readerFor(Bean.class).readValues(JSON);
+        MappingIterator<Bean> it = MAPPER.readerFor(Bean.class)
+                .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                .readValues(JSON);
         Bean bean = it.nextValue();
 
         assertNotNull(bean);

src/test/java/tools/jackson/databind/struct/TestPOJOAsArray.java

@@ -295,7 +295,9 @@ public void testUnknownExtraProp() throws Exception
     {
         String json = "{\"value\":[true,\"Foobar\",42,13, false]}";
         try {
-            MAPPER.readValue(json, PojoAsArrayWrapper.class);
+            MAPPER.readerFor(PojoAsArrayWrapper.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(json);
             fail("should not pass with extra element");
         } catch (MismatchedInputException e) {
             verifyException(e, "Unexpected JSON values");

src/test/java/tools/jackson/databind/struct/TestPOJOAsArrayWithBuilder.java

@@ -195,7 +195,9 @@ public void testUnknownExtraProp() throws Exception
     {
         String json = "[1, 2, 3, 4]";
         try {
-            MAPPER.readValue(json, ValueClassXY.class);
+            MAPPER.readerFor(ValueClassXY.class)
+                    .with(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                    .readValue(json);
             fail("should not pass with extra element");
         } catch (MismatchedInputException e) {
             verifyException(e, "Unexpected JSON values");