Support constructor based so we can map Records as destinations

Author: Chun-Han Hsiao

pom.xml

@@ -16,7 +16,7 @@
   <properties>
     <maven.compiler.source>17</maven.compiler.source>
     <maven.compiler.target>17</maven.compiler.target>
-    <modelmapper.version>3.1.1</modelmapper.version>
+    <modelmapper.version>3.2.6</modelmapper.version>
     <testng.version>7.7.0</testng.version>
   </properties>
   <licenses>

src/main/java/org/modelmapper/record/RecordConstructorInjector.java

@@ -0,0 +1,31 @@
+package org.modelmapper.record;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.RecordComponent;
+import java.util.stream.IntStream;
+import org.modelmapper.ConstructorParam;
+import org.modelmapper.spi.ConstructorInjector;
+
+import java.util.List;
+
+public class RecordConstructorInjector implements ConstructorInjector {
+
+  @Override
+  public List<ConstructorParam> getParameters(Class<?> type) {
+    if (!isApplicable(type)) {
+      throw new IllegalArgumentException(
+          String.format("Type %s is not a Record type.", type.getName()));
+    }
+    Constructor<?> constructor = type.getDeclaredConstructors()[0];
+    RecordComponent[] components = type.getRecordComponents();
+    return IntStream.range(0, components.length)
+        .mapToObj(index -> new ConstructorParam(constructor, index, components[index].getName(),
+            components[index].getType()))
+        .toList();
+  }
+
+  @Override
+  public boolean isApplicable(Class<?> type) {
+    return Record.class.isAssignableFrom(type);
+  }
+}

src/main/java/org/modelmapper/record/RecordModule.java

@@ -7,5 +7,7 @@ public class RecordModule implements Module {
   @Override
   public void setupModule(ModelMapper modelMapper) {
     modelMapper.getConfiguration().addValueReader(new RecordValueReader());
+    modelMapper.getConfiguration().addConstructorInjector(
+        new RecordConstructorInjector());
   }
 }

src/test/java/org/modelmapper/record/RecordConstructorInjectorTest.java

@@ -0,0 +1,45 @@
+package org.modelmapper.record;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNull;
+
+import org.modelmapper.ModelMapper;
+import org.modelmapper.config.Configuration.AccessLevel;
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+
+/**
+ * Tests the mapping of a POJO to a Record.
+ */
+@Test
+public class RecordConstructorInjectorTest {
+  private ModelMapper modelMapper;
+
+  record UserRecord(String userId, String userName) {
+  }
+
+  static class User {
+    String userId;
+    String userName;
+  }
+
+  @BeforeMethod
+  public void setup() {
+    modelMapper = new ModelMapper()
+        .registerModule(new RecordModule());
+    modelMapper.getConfiguration()
+        .setFieldMatchingEnabled(true)
+        .setFieldAccessLevel(AccessLevel.PACKAGE_PRIVATE)
+        .setMethodAccessLevel(AccessLevel.PACKAGE_PRIVATE);
+  }
+
+  public void shouldMapToRecord() {
+    User user = new User();
+    user.userId = "id";
+    user.userName = "name";
+
+    UserRecord record = modelMapper.map(user, UserRecord.class);
+    assertEquals(record.userId, "id");
+    assertEquals(record.userName, "name");
+  }
+}