Fix #2543: Skip delegating creator arguments when collecting properties

release-notes/CREDITS-2.x

@@ -1756,3 +1756,8 @@ Jesper Blomquist (jebl01@github)
 András Péteri (apeteri@github)
  * Suggested #4416: Deprecate `JsonNode.asText(String)`
   (2.17.0)
+
+Kyrylo Merzlikin (kirmerzlikin@github)
+ * Contributed fix for #2543: Introspection includes delegating ctor's
+   only parameter as a property in `BeanDescription`
+  (2.17.0)

release-notes/VERSION-2.x

@@ -12,6 +12,10 @@ Project: jackson-databind
 #736: `MapperFeature.REQUIRE_SETTERS_FOR_GETTERS` has no effect
  (reported by @migel)
  (fix contributed by Joo-Hyuk K)
+#2543: Introspection includes delegating ctor's only parameter as
+  a property in `BeanDescription`
+ (reported by @nikita2206)
+ (fix contributed by Kyrylo M)
 #4160: Deprecate `DefaultTyping.EVERYTHING` in `2.x` and remove in `3.0`
  (contributed by Joo-Hyuk K)
 #4194: Add `JsonNodeFeature.FAIL_ON_NAN_TO_BIG_DECIMAL_COERCION` option to

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

@@ -760,7 +760,11 @@ private void _addCreatorParam(Map<String, POJOPropertyBuilder> props,
             // ...or is a Records canonical constructor
             boolean isCanonicalConstructor = recordComponentName != null;
 
-            if ((creatorMode == null || creatorMode == JsonCreator.Mode.DISABLED) && !isCanonicalConstructor) {
+            if ((creatorMode == null
+                    || creatorMode == JsonCreator.Mode.DISABLED
+                    // 12-Mar-2024: [databind#2543] need to skip delegating as well
+                    || creatorMode == JsonCreator.Mode.DELEGATING)
+                    && !isCanonicalConstructor) {
                 return;
             }
             pn = PropertyName.construct(impl);

src/test/java/com/fasterxml/jackson/databind/deser/creators/DelegatingCreatorImplicitNames2543Test.java

@@ -0,0 +1,83 @@
+package com.fasterxml.jackson.databind.deser.creators;
+
+import java.util.Objects;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.introspect.*;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import static com.fasterxml.jackson.annotation.JsonCreator.Mode.DELEGATING;
+import static com.fasterxml.jackson.annotation.JsonCreator.Mode.PROPERTIES;
+
+public class DelegatingCreatorImplicitNames2543Test
+    extends DatabindTestUtil
+{
+    static class Data {
+
+        final String part1;
+        final String part2;
+
+        // this creator is considered a source of settable bean properties,
+        // used during deserialization
+        @JsonCreator(mode = PROPERTIES)
+        public Data(@JsonProperty("part1") String part1,
+                    @JsonProperty("part2") String part2) {
+            this.part1 = part1;
+            this.part2 = part2;
+        }
+
+        // no properties should be collected from this creator,
+        // even though it has an argument with an implicit name
+        @JsonCreator(mode = DELEGATING)
+        public static Data fromFullData(String fullData) {
+            String[] parts = fullData.split("\\s+", 2);
+            return new Data(parts[0], parts[1]);
+        }
+    }
+
+    static class DelegatingCreatorNamedArgumentIntrospector
+            extends JacksonAnnotationIntrospector {
+        private static final long serialVersionUID = 1L;
+
+        @Override
+        public String findImplicitPropertyName(AnnotatedMember member) {
+            if (member instanceof AnnotatedParameter) {
+                AnnotatedWithParams owner = ((AnnotatedParameter) member).getOwner();
+                if (owner instanceof AnnotatedMethod) {
+                    AnnotatedMethod method = (AnnotatedMethod) owner;
+                    if (Objects.requireNonNull(method.getAnnotation(JsonCreator.class)).mode() == DELEGATING)
+                        return "fullData";
+                }
+            }
+            return super.findImplicitPropertyName(member);
+        }
+    }
+
+    private static final ObjectMapper MAPPER = JsonMapper.builder()
+            .annotationIntrospector(new DelegatingCreatorNamedArgumentIntrospector())
+            .build();
+
+    @Test
+    public void testDeserialization() throws Exception {
+        Data data = MAPPER.readValue(a2q("{'part1':'a','part2':'b'}"), Data.class);
+
+        assertThat(data.part1).isEqualTo("a");
+        assertThat(data.part2).isEqualTo("b");
+    }
+
+    @Test
+    public void testDelegatingDeserialization() throws Exception {
+        Data data = MAPPER.readValue(a2q("'a b'"), Data.class);
+
+        assertThat(data.part1).isEqualTo("a");
+        assertThat(data.part2).isEqualTo("b");
+    }
+}