[2.0.0-beta1] Validation error with empty attribute object in link

I will have a look

@grimreaper, OK with that? If yes, let's ask Steven to review and to confirm the usefulness of such a change.

Sorry for this stupid mistake. I have amended the commit.

The work may not be not over anyway:

Steven - Today at 1:48 AM
unfortunately still seems broken without ui devel
May be related but is the LinksPropType normalize suppose to turn the attributes into an array vs a Drupal Attribute object?
Pierre - Today at 7:49 AM
indeed. It was necessary a few month ago because we were running normalize before SDC validator, but it seems we are now running it after SDC validator, so we may be able to remove this part.

So, I will test that

2 big changes:

1

I have added Steven's example to the test cases and I understood the normalization of link_attributes was not happenig at the right place.

Preventing the possibility of defining link_attributes manually in presenter templates:

      [
        "title" => 0,
        "url" => "?page=0",
        "attributes" => new Attribute(),
        "link_attributes" => new Attribute([
          'class' => [
            'display-flex',
            'flex-align-center',
            'flex-no-wrap',
          ],
        ]),
      ]

https://git.drupalcode.org/project/ui_patterns/-/merge_requests/166/diff...

2

I have improved the management of link_attributes by merging existing values with the ones extracted from the Url objects.

And I removed the transformation of Attribute objects to arrays, because SDC is not complaining anymore about that. Maybe because PropTypeInterface::normalize() now happens after the SDC validator is run.

https://git.drupalcode.org/project/ui_patterns/-/merge_requests/166/diff...