@Test
public void testMissingCustomDataType() throws Exception {

    List<ValidationMessage> messages = service.validate(path,
                                                        loadFile("missingCustomDataTypeDefinition.wid"));
    assertEquals(1,
                 messages.size());
    assertTrue("Expected error about missing import",
               messages.get(0).getText().contains("Error: could not resolve class: MyCustomDataType"));
}