Bug reproduction for #3220

src/test/java/com/fasterxml/jackson/databind/deser/MixingFactoryMethodTest.java

@@ -0,0 +1,151 @@
+package com.fasterxml.jackson.databind.deser;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonGetter;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.util.Objects;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class MixingFactoryMethodTest {
+    public static class Timestamped<T> {
+        private final T value;
+        private final int timestamp;
+
+        private Timestamped(T value, int timestamp) {
+            this.value = value;
+            this.timestamp = timestamp;
+        }
+
+        public static <T> Timestamped<T> stamp(T value, int timestamp) {
+            return new Timestamped<>(value, timestamp);
+        }
+
+        public T getValue() {
+            return value;
+        }
+
+        public int getTimestamp() {
+            return timestamp;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            Timestamped<?> that = (Timestamped<?>) o;
+            return timestamp == that.timestamp && Objects.equals(value, that.value);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(value, timestamp);
+        }
+    }
+
+    public abstract static class TimestampedMixin<T> {
+        @JsonCreator
+        public static <T> void stamp(
+            @JsonProperty("value") T value,
+            @JsonProperty("timestamp") int timestamp
+        ) {
+        }
+
+        @JsonGetter("value")
+        abstract T getValue();
+
+        @JsonGetter("timestamp")
+        abstract int getTimestamp();
+    }
+
+    public static class Profile {
+        private final String firstName;
+        private final String lastName;
+
+        @JsonCreator
+        public Profile(
+            @JsonProperty("firstName")
+                String firstName,
+            @JsonProperty("lastName")
+                String lastName
+        ) {
+            this.firstName = firstName;
+            this.lastName = lastName;
+        }
+
+        @JsonGetter("firstName")
+        public String getFirstName() {
+            return firstName;
+        }
+
+        @JsonGetter("lastName")
+        public String getLastName() {
+            return lastName;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            Profile profile = (Profile) o;
+            return Objects.equals(firstName, profile.firstName) && Objects.equals(lastName, profile.lastName);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(firstName, lastName);
+        }
+    }
+
+    public static class User {
+        private final Timestamped<Profile> profile;
+
+        @JsonCreator
+        private User(
+            @JsonProperty("profile")
+                Timestamped<Profile> profile
+        ) {
+            this.profile = profile;
+        }
+
+        @JsonGetter("profile")
+        public Timestamped<Profile> getProfile() {
+            return profile;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            User user = (User) o;
+            return Objects.equals(profile, user.profile);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(profile);
+        }
+    }
+
+    @Test
+    public void testMixin() throws JsonProcessingException {
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.addMixIn(Timestamped.class, TimestampedMixin.class);
+
+        Profile profile = new Profile("Jackson", "Databind");
+        User user = new User(new Timestamped<>(profile, 1));
+
+        User deserializedUser = mapper.readValue(
+            mapper.writerFor(User.class).writeValueAsString(user),
+            User.class
+        );
+
+        Profile deserializedProfile = deserializedUser.getProfile().getValue();
+
+        assertEquals(profile, deserializedProfile);
+        assertEquals(user, deserializedUser);
+    }
+}