@Test
public void propertyAlreadyPresentErrorTest() throws IOException {

    PomAddProperty pomAddProperty = new PomAddProperty("encoding", "bar").relative("pom.xml").failIfPresent();
    TOExecutionResult executionResult = pomAddProperty.execution(transformedAppFolder, transformationContext);
    assertEquals(executionResult.getType(), TOExecutionResult.Type.ERROR);
    assertEquals(executionResult.getException().getClass(), TransformationOperationException.class);
    assertEquals(executionResult.getException().getMessage(), "Property encoding was not added to POM file pom.xml because it is already present");
    assertNull(executionResult.getException().getCause());
    assertNull(executionResult.getDetails());
    assertNotChangedFile("pom.xml");
    // Asserting that the default result type is ERROR, in case a property is not present
    assertEquals(new PomAddProperty("encoding", "bar").relative("pom.xml").execution(transformedAppFolder, transformationContext).getType(), TOExecutionResult.Type.ERROR);
}