DATACMNS-1171 - Do not create PersistentEntity for unsupported Kotlin classes.

We now reject unsupported Kotlin classes from the MappingContext by default by not creating persistent entities.

Original pull request: #245.

src/test/java/org/springframework/data/mapping/context/AbstractMappingContextUnitTests.java

@@ -45,6 +45,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Oliver Gierke
  * @author Thomas Darimont
+ * @author Mark Paluch
  */
 public class AbstractMappingContextUnitTests {
 
@@ -210,6 +211,16 @@ public class AbstractMappingContextUnitTests {
 		assertHasEntityFor(TreeMap.class, context, false);
 	}
 
+	@Test // DATACMNS-1171
+	public void shouldCreateEntityForKotlinDataClass() {
+		assertThat(context.getPersistentEntity(SimpleDataClass.class)).isNotNull();
+	}
+
+	@Test // DATACMNS-1171
+	public void shouldNotCreateEntityForSyntheticKotlinClass() {
+		assertThat(context.getPersistentEntity(TypeCreatingSyntheticClass.class)).isNotNull();
+	}
+
 	@Test // DATACMNS-695
 	public void persistentPropertyPathTraversesGenericTypesCorrectly() {
 		assertThat(context.getPersistentPropertyPath("field.wrapped.field", Outer.class)).hasSize(3);