ComponentMetadataRequirementsChecker::check() should validate no prop is of type object

I’d swear this was already working, but I guess not?! 🤪

Thanks to the solid test infra + @penyaskito’s excellent issue summary, I believe this is doable for a novice contributor 😊

Turns out there are already some SDC components, using "object" already committed to the `xb_test_sdc` testing

Specifically these SDCs:

tests/modules/xb_test_sdc/components/image-optional-with-example
tests/modules/xb_test_sdc/components/image-optional-with-example-and-additional-prop
tests/modules/xb_test_sdc/components/image-optional-without-example/image-optional-without-example.component.yml
tests/modules/xb_test_sdc/components/image-required-with-example
tests/modules/xb_test_sdc/components/image-required-with-invalid-example
tests/modules/xb_test_sdc/components/image-required-without-example

This was uncovered in a slack chat with @penyaskito.. It was also mentioned in the chat that an array of objects is OK.

Looking at config/schema/experience_builder.json_schema we can find that type: object is valid, but only if $ref is defined too:

    '$ref':
      # ⚠️ Note the absence of `requiredKey: false` here: XB does not (yet) support arbitrary `type: object` shapes, so
      # `$ref` is actually REQUIRED for such props!

In /schema.json we can see the accepted values for $ref.

So we should validate in ComponentMetadataRequirementsChecker::check that if type is object, $ref is present.

Later we could actually validate that $ref is one of the valid values (only json-schema-definitions://experience_builder.module/image for now), but we probably want to leave that out for now.

Updated the requirements in the issue summary.

Looking at config/schema/experience_builder.json_schema we can find that type: object is valid, but only if $ref is defined too:

Correct. Because we don't have 📌 [PP-1] Support `{type: object, …}` prop shapes that require *multiple* field types Postponed yet. See \Drupal\experience_builder\JsonSchemaInterpreter\JsonSchemaType::computeStorablePropShape() and \Drupal\experience_builder\Hook\ShapeMatchingHooks::datetimeRangeStoragePropShapeAlter() — those are the two only object shapes currently supported by XB.

Later we could actually validate that $ref is one of the valid values (only json-schema-definitions://experience_builder.module/image for now), but we probably want to leave that out for now.

That is actually already handled in \Drupal\experience_builder\ComponentMetadataRequirementsChecker::check(), thanks to this bit:

      // Every prop must have a StorablePropShape.
      $component_prop_expression = new ComponentPropExpression($component_id, $prop_name);
      $prop_shape = $props_for_metadata[(string) $component_prop_expression];
      $storable_prop_shape = $prop_shape->getStorage();
      if ($storable_prop_shape instanceof StorablePropShape) {
        continue;
      }
      $messages[] = \sprintf('Experience Builder does not know of a field type/widget to allow populating the <code>%s

prop, with the shape %s.', $prop_name, json_encode($prop_shape->schema, JSON_UNESCAPED_SLASHES));

Wow, looks like @partyka pretty much did everything needed here, but just didn't create an MR yet? :D

Awesome, thanks so much! 🤩

Lovely, thanks, @partyka! 😊