DATAJPA-1535 - Polishing.

Use isNew(…) check in delete(T) instead of just relying on Id nullability. Formatting.

Original pull request: #378.

src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -169,13 +169,11 @@ public class SimpleJpaRepository<T, ID> implements JpaRepositoryImplementation<T
 
 		Assert.notNull(entity, "The entity must not be null!");
 
-		Object id = entityInformation.getId(entity);
-		if (id == null) {
+		if (entityInformation.isNew(entity)) {
 			return;
 		}
 
-		T existing = em.find(entityInformation.getJavaType(), id);
-
+		T existing = em.find(entityInformation.getJavaType(), entityInformation.getId(entity));
 		// if the entity to be deleted doesn't exist, delete is a NOOP
 		if (existing == null) {
 			return;

src/test/java/org/springframework/data/jpa/repository/EclipseLinkNamespaceUserRepositoryTests.java

@@ -174,12 +174,13 @@ public class EclipseLinkNamespaceUserRepositoryTests extends NamespaceUserReposi
 		super.findByEmptyCollectionOfStrings();
 	}
 
+	/**
+	 * Ignores the test for EclipseLink.
+	 */
 	@Override
 	@Test
 	@Ignore
-	public void savingUserThrowsAnException() {
-		super.savingUserThrowsAnException();
-	}
+	public void savingUserThrowsAnException() {}
 
 	private void assumeNotEclipseLink2_7_2plus() {
 

src/test/java/org/springframework/data/jpa/repository/UserRepositoryTests.java

@@ -2211,9 +2211,10 @@ public class UserRepositoryTests {
 		assertThat(repository.findByEmailNativeAddressJdbcStyleParameter("gierke@synyx.de")).isEqualTo(firstUser);
 	}
 
-	@Test() // DATAJPA-1535
+	@Test // DATAJPA-1535
 	public void savingUserThrowsAnException() {
-		// if this test fails this means deleteNewInstanceSucceedsByDoingNothing() might actually save the user without the test failing, which would be a bad thing.
+		// if this test fails this means deleteNewInstanceSucceedsByDoingNothing() might actually save the user without the
+		// test failing, which would be a bad thing.
 		assertThatThrownBy(() -> repository.save(new User())).isInstanceOf(DataIntegrityViolationException.class);
 	}
 

src/test/java/org/springframework/data/jpa/repository/support/SimpleJpaRepositoryUnitTests.java

@@ -171,7 +171,7 @@ public class SimpleJpaRepositoryUnitTests {
 	}
 
 	@Test // DATAJPA-1535
-	public void doNothingWhenNonExistantInstanceGetsDeleted() {
+	public void doNothingWhenNonExistentInstanceGetsDeleted() {
 
 		User newUser = new User();
 		newUser.setId(23);