[DependencyInjection] [DX] Unhelpful error message when being stupid while declaring a service as a factory #18598
Description
Wrong:
<factory id="foo.factory" class="FooFactory"/>
Correct:
<factory service="foo.factory" class="FooFactory"/>
When doing it incorrectly, the error message says this:
RuntimeException in PhpDumper.php line 1437: Cannot dump definition because of invalid class name ('')
Maybe instead we can complain that the configuration is broken with a more meaningful error message.