Use primary copy method for Kotlin data classes.

We now resolve the copy method for Kotlin data classes that match the primary constructor. Previously, copy method resolution could find a secondary copy method as we didn't check for the primary constructor structure (parameter names and types).

Closes #2324.

src/test/java/org/springframework/data/mapping/model/ClassGeneratingPropertyAccessorFactoryEntityTypeTests.java

@@ -18,10 +18,12 @@ package org.springframework.data.mapping.model;
 import static org.assertj.core.api.Assertions.*;
 
 import java.io.Serializable;
+import java.time.LocalDateTime;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mapping.PersistentEntity;
+import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.context.SampleMappingContext;
 import org.springframework.data.mapping.context.SamplePersistentProperty;
 import org.springframework.data.repository.core.EntityInformation;
@@ -32,6 +34,7 @@ import org.springframework.data.repository.core.support.PersistentEntityInformat
  *
  * @author John Blum
  * @author Oliver Gierke
+ * @author Mark Paluch
  */
 public class ClassGeneratingPropertyAccessorFactoryEntityTypeTests {
 
@@ -53,6 +56,17 @@ public class ClassGeneratingPropertyAccessorFactoryEntityTypeTests {
 		assertThat(getEntityInformation(Person.class).getId(jonDoe)).isEqualTo(jonDoe.name);
 	}
 
+	@Test // #2324
+	public void shouldGeneratePropertyAccessorForKotlinClassWithMultipleCopyMethods() {
+
+		ClassGeneratingPropertyAccessorFactory factory = new ClassGeneratingPropertyAccessorFactory();
+		PersistentPropertyAccessor<WithCustomCopyMethod> propertyAccessor = factory.getPropertyAccessor(
+				mappingContext.getRequiredPersistentEntity(WithCustomCopyMethod.class),
+				new WithCustomCopyMethod("", "", "", 1, LocalDateTime.MAX, LocalDateTime.MAX, ""));
+
+		assertThat(propertyAccessor).isNotNull();
+	}
+
 	private EntityInformation<Object, Serializable> getEntityInformation(Class<?> type) {
 
 		PersistentEntity<Object, SamplePersistentProperty> entity = mappingContext.getRequiredPersistentEntity(type);

src/test/java/org/springframework/data/mapping/model/KotlinCopyMethodUnitTests.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mapping.model;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.Optional;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.data.mapping.context.SampleMappingContext;
+
+/**
+ * Unit tests for {@link KotlinCopyMethod}.
+ *
+ * @author Mark Paluch
+ */
+class KotlinCopyMethodUnitTests {
+
+	SampleMappingContext mappingContext = new SampleMappingContext();
+
+	@Test // #2324
+	void shouldLookupPrimaryConstructor() {
+
+		Optional<KotlinCopyMethod> optional = KotlinCopyMethod.findCopyMethod(DataClassKt.class);
+
+		assertThat(optional).hasValueSatisfying(actual -> {
+			// $this, 1 component, 1 defaulting mask, 1 Object marker
+			assertThat(actual.getSyntheticCopyMethod().getParameterCount()).isEqualTo(4);
+
+			// $this, 1 component
+			assertThat(actual.getCopyFunction().getParameters()).hasSize(2);
+		});
+	}
+
+	@Test // #2324
+	void shouldLookupPrimaryConstructorWhenTwoCopyMethodsArePresent() {
+
+		Optional<KotlinCopyMethod> optional = KotlinCopyMethod.findCopyMethod(WithCustomCopyMethod.class);
+
+		assertThat(optional).hasValueSatisfying(actual -> {
+			// $this, 7 components, 1 defaulting mask, 1 Object marker
+			assertThat(actual.getSyntheticCopyMethod().getParameterCount()).isEqualTo(10);
+
+			// $this, 7 components
+			assertThat(actual.getCopyFunction().getParameters()).hasSize(8);
+
+			assertThat(
+					actual.shouldUsePublicCopyMethod(mappingContext.getRequiredPersistentEntity(WithCustomCopyMethod.class)))
+							.isFalse();
+		});
+	}
+
+	@Test // #2324
+	void shouldUsePublicKotlinMethodForSinglePropertyEntities() {
+
+		KotlinCopyMethod copyMethod = KotlinCopyMethod.findCopyMethod(DataClassKt.class).get();
+
+		assertThat(copyMethod.shouldUsePublicCopyMethod(mappingContext.getRequiredPersistentEntity(DataClassKt.class)))
+				.isTrue();
+	}
+}