Disable Jackson's FAIL_ON_UNKNOWN_PROPERTIES by default

Also provide a way to go back to the previous behavior.

docs/src/main/asciidoc/rest-json.adoc

@@ -186,7 +186,14 @@ It will allow to narrow down the number of JAX-RS providers (which can be seen a
 
 ==== Jackson
 
-Quarkus makes it very easy to configure various Jackson settings via CDI beans. The simplest (and suggested) approach is to define a CDI bean of type `io.quarkus.jackson.ObjectMapperCustomizer`
+In Quarkus, the default Jackson `ObjectMapper` obtained via CDI (and consumed by the Quarkus extensions) is configured to ignore unknown properties
+(by disabling the `DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES` feature).
+
+You can restore the default behavior of Jackson by setting `quarkus.jackson.fail-on-unknown-properties=true` in your `application.properties`
+or on a per class basis via `@JsonIgnoreProperties(ignoreUnknown = false)`.
+
+Also, Quarkus makes it very easy to configure various Jackson settings via CDI beans.
+The simplest (and suggested) approach is to define a CDI bean of type `io.quarkus.jackson.ObjectMapperCustomizer`
 inside of which any Jackson configuration can be applied.
 
 An example where a custom module needs to be registered would look like so:

extensions/jackson/deployment/pom.xml

@@ -30,6 +30,11 @@
             <groupId>io.quarkus</groupId>
             <artifactId>quarkus-jackson</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5-internal</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

extensions/jackson/deployment/src/main/java/io/quarkus/jackson/deployment/JacksonProcessor.java

@@ -29,9 +29,12 @@
 import io.quarkus.arc.deployment.AdditionalBeanBuildItem;
 import io.quarkus.arc.deployment.GeneratedBeanBuildItem;
 import io.quarkus.arc.deployment.GeneratedBeanGizmoAdaptor;
+import io.quarkus.arc.deployment.SyntheticBeanBuildItem;
 import io.quarkus.deployment.Capability;
 import io.quarkus.deployment.annotations.BuildProducer;
 import io.quarkus.deployment.annotations.BuildStep;
+import io.quarkus.deployment.annotations.ExecutionTime;
+import io.quarkus.deployment.annotations.Record;
 import io.quarkus.deployment.builditem.CapabilityBuildItem;
 import io.quarkus.deployment.builditem.CombinedIndexBuildItem;
 import io.quarkus.deployment.builditem.nativeimage.ReflectiveClassBuildItem;
@@ -43,6 +46,9 @@
 import io.quarkus.gizmo.MethodDescriptor;
 import io.quarkus.gizmo.ResultHandle;
 import io.quarkus.jackson.ObjectMapperCustomizer;
+import io.quarkus.jackson.runtime.JacksonBuildTimeConfig;
+import io.quarkus.jackson.runtime.JacksonConfigSupport;
+import io.quarkus.jackson.runtime.JacksonRecorder;
 import io.quarkus.jackson.runtime.ObjectMapperProducer;
 import io.quarkus.jackson.spi.ClassPathJacksonModuleBuildItem;
 import io.quarkus.jackson.spi.JacksonModuleBuildItem;
@@ -168,6 +174,16 @@ private void registerModuleIfOnClassPath(String moduleClassName,
         }
     }
 
+    @BuildStep
+    @Record(ExecutionTime.STATIC_INIT)
+    SyntheticBeanBuildItem pushConfigurationBean(JacksonRecorder jacksonRecorder,
+            JacksonBuildTimeConfig jacksonBuildTimeConfig) {
+        return SyntheticBeanBuildItem.configure(JacksonConfigSupport.class)
+                .scope(Singleton.class)
+                .supplier(jacksonRecorder.jacksonConfigSupport(jacksonBuildTimeConfig))
+                .done();
+    }
+
     // Generate a ObjectMapperCustomizer bean that registers each serializer / deserializer as well as detected modules with the ObjectMapper
     @BuildStep
     void generateCustomizer(BuildProducer<GeneratedBeanBuildItem> generatedBeans,

extensions/jackson/deployment/src/test/java/io/quarkus/jackson/deployment/JacksonFailOnUnknownPropertiesTest.java

@@ -0,0 +1,35 @@
+package io.quarkus.jackson.deployment;
+
+import javax.inject.Inject;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException;
+
+import io.quarkus.test.QuarkusUnitTest;
+
+public class JacksonFailOnUnknownPropertiesTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withConfigurationResource("application-fail-on-unknown-properties.properties");
+
+    @Inject
+    ObjectMapper objectMapper;
+
+    @Test
+    public void testFailOnUnknownProperties() throws JsonMappingException, JsonProcessingException {
+        Assertions.assertThrows(UnrecognizedPropertyException.class,
+                () -> objectMapper.readValue("{\"property\": \"name\", \"unknownProperty\": \"unknown\"}", Pojo.class));
+    }
+
+    public static class Pojo {
+
+        public String property;
+    }
+}

extensions/jackson/deployment/src/test/java/io/quarkus/jackson/deployment/JacksonIgnoreUnknownPropertiesTest.java

@@ -0,0 +1,34 @@
+package io.quarkus.jackson.deployment;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import javax.inject.Inject;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import io.quarkus.test.QuarkusUnitTest;
+
+public class JacksonIgnoreUnknownPropertiesTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest();
+
+    @Inject
+    ObjectMapper objectMapper;
+
+    @Test
+    public void testIgnoreUnknownProperties() throws JsonMappingException, JsonProcessingException {
+        Pojo pojo = objectMapper.readValue("{\"property\": \"name\", \"unknownProperty\": \"unknown\"}", Pojo.class);
+        assertEquals("name", pojo.property);
+    }
+
+    public static class Pojo {
+
+        public String property;
+    }
+}

extensions/jackson/deployment/src/test/resources/application-fail-on-unknown-properties.properties

@@ -0,0 +1 @@
+quarkus.jackson.fail-on-unknown-properties=true

extensions/jackson/runtime/src/main/java/io/quarkus/jackson/runtime/JacksonBuildTimeConfig.java

@@ -0,0 +1,16 @@
+package io.quarkus.jackson.runtime;
+
+import io.quarkus.runtime.annotations.ConfigItem;
+import io.quarkus.runtime.annotations.ConfigRoot;
+
+@ConfigRoot
+public class JacksonBuildTimeConfig {
+
+    /**
+     * If enabled, Jackson will fail when encountering unknown properties.
+     * <p>
+     * You can still override it locally with {@code @JsonIgnoreProperties(ignoreUnknown = false)}.
+     */
+    @ConfigItem(defaultValue = "false")
+    public boolean failOnUnknownProperties;
+}

extensions/jackson/runtime/src/main/java/io/quarkus/jackson/runtime/JacksonConfigSupport.java

@@ -0,0 +1,14 @@
+package io.quarkus.jackson.runtime;
+
+public class JacksonConfigSupport {
+
+    private boolean failOnUnknownProperties;
+
+    public JacksonConfigSupport(boolean failOnUnknownProperties) {
+        this.failOnUnknownProperties = failOnUnknownProperties;
+    }
+
+    public boolean isFailOnUnknownProperties() {
+        return failOnUnknownProperties;
+    }
+}

extensions/jackson/runtime/src/main/java/io/quarkus/jackson/runtime/JacksonRecorder.java

@@ -0,0 +1,19 @@
+package io.quarkus.jackson.runtime;
+
+import java.util.function.Supplier;
+
+import io.quarkus.runtime.annotations.Recorder;
+
+@Recorder
+public class JacksonRecorder {
+
+    public Supplier<JacksonConfigSupport> jacksonConfigSupport(JacksonBuildTimeConfig jacksonBuildTimeConfig) {
+        return new Supplier<JacksonConfigSupport>() {
+
+            @Override
+            public JacksonConfigSupport get() {
+                return new JacksonConfigSupport(jacksonBuildTimeConfig.failOnUnknownProperties);
+            }
+        };
+    }
+}

extensions/jackson/runtime/src/main/java/io/quarkus/jackson/runtime/ObjectMapperProducer.java

@@ -9,6 +9,7 @@
 import javax.enterprise.inject.Produces;
 import javax.inject.Singleton;
 
+import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 import io.quarkus.arc.DefaultBean;
@@ -20,8 +21,13 @@ public class ObjectMapperProducer {
     @DefaultBean
     @Singleton
     @Produces
-    public ObjectMapper objectMapper(Instance<ObjectMapperCustomizer> customizers) {
+    public ObjectMapper objectMapper(Instance<ObjectMapperCustomizer> customizers,
+            JacksonConfigSupport jacksonConfigSupport) {
         ObjectMapper objectMapper = new ObjectMapper();
+        if (!jacksonConfigSupport.isFailOnUnknownProperties()) {
+            // this feature is enabled by default, so we disable it
+            objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
+        }
         List<ObjectMapperCustomizer> sortedCustomizers = sortCustomizersInDescendingPriorityOrder(customizers);
         for (ObjectMapperCustomizer customizer : sortedCustomizers) {
             customizer.customize(objectMapper);