Avoid mutator-inference for Records (to avoid pulling in Fields as mutators) (#3737)

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -26,6 +26,7 @@ Project: jackson-databind
  (reported by João G)
 #3708: Seems like `java.nio.file.Path` is safe for Android API level 26
  (contributed by @pjfanning)
+#3736: Try to avoid auto-detecting Fields for Record types
 
 2.14.2 (not yet released)
 

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

@@ -61,6 +61,11 @@ public class POJOPropertiesCollector
      */
     protected final boolean _useAnnotations;
 
+    /**
+     * @since 2.15
+     */
+    protected final boolean _isRecordType;
+
     /*
     /**********************************************************
     /* Collected property information
@@ -170,6 +175,7 @@ protected POJOPropertiesCollector(MapperConfig<?> config, boolean forSerializati
         _forSerialization = forSerialization;
         _type = type;
         _classDef = classDef;
+        _isRecordType = _type.isRecordType();
         if (config.isAnnotationProcessingEnabled()) {
             _useAnnotations = true;
             _annotationIntrospector = _config.getAnnotationIntrospector();
@@ -225,7 +231,7 @@ public JavaType getType() {
      * @since 2.15
      */
     public boolean isRecordType() {
-        return _type.isRecordType();
+        return _isRecordType;
     }
 
     public AnnotatedClass getClassDef() {
@@ -431,7 +437,12 @@ protected void collectAll()
         LinkedHashMap<String, POJOPropertyBuilder> props = new LinkedHashMap<String, POJOPropertyBuilder>();
 
         // First: gather basic data
-        _addFields(props); // note: populates _fieldRenameMappings
+
+        // 15-Jan-2023, tatu: [databind#3736] Let's avoid detecting fields of Records
+        //   altogether (unless we find a good reason to detect them)
+        if (!isRecordType()) {
+            _addFields(props); // note: populates _fieldRenameMappings
+        }
         _addMethods(props);
         // 25-Jan-2016, tatu: Avoid introspecting (constructor-)creators for non-static
         //    inner classes, see [databind#1502]
@@ -994,7 +1005,10 @@ protected void _removeUnwantedProperties(Map<String, POJOPropertyBuilder> props)
      */
     protected void _removeUnwantedAccessor(Map<String, POJOPropertyBuilder> props)
     {
-        final boolean inferMutators = _config.isEnabled(MapperFeature.INFER_PROPERTY_MUTATORS);
+        // 15-Jan-2023, tatu: Avoid pulling in mutators for Records; Fields mostly
+        //    since there should not be setters.
+        final boolean inferMutators = !isRecordType()
+                && _config.isEnabled(MapperFeature.INFER_PROPERTY_MUTATORS);
         Iterator<POJOPropertyBuilder> it = props.values().iterator();
 
         while (it.hasNext()) {

src/test-jdk14/java/com/fasterxml/jackson/databind/records/RecordCreatorsTest.java

@@ -5,6 +5,7 @@
 import com.fasterxml.jackson.annotation.JsonValue;
 
 import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException;
 
 public class RecordCreatorsTest extends BaseMapTest
 {
@@ -62,11 +63,11 @@ public void testDeserializeWithAltCtor() throws Exception {
         try {
             MAPPER.readValue("{\"id\":2812,\"name\":\"Bob\"}",
                     RecordWithAltCtor.class);
-
             fail("should not pass");
-        } catch (JsonMappingException e) {
-            verifyException(e, "Can not set final java.lang.String field");
-            verifyException(e, "RecordWithAltCtor.name");
+        } catch (UnrecognizedPropertyException e) {
+            verifyException(e, "Unrecognized");
+            verifyException(e, "\"name\"");
+            verifyException(e, "RecordWithAltCtor");
         }
     }