Default content exports are invalid and hence are not correct after importing

wim leers → credited justafish → .

OMG, AFAICT \Drupal\Core\DefaultContent\Importer exists but not \Drupal\Core\DefaultContent\Exporter?! CR: https://www.drupal.org/node/3445169 → .

I'm hoping that @phenaproxima can push this forward 😇

Ironically I surfaced something closely related in reviewing that Recipes MR a ~year ago: #3439923-31: Add recipes api as experimental API to core → + @phenaproxima's response at -32, where he says:

it's exported by the default_content module, which is what generates these YAML files. IMHO they should not be changed at this time, but if (which, once this is committed, is really when) core adds the ability to export content entities as YAML […]

😭😬 — no related issues linked from #3439923 that are doing that, and search engines aren't finding such an issue either…

@phenaproxima: I suspect that the NULL values stored in the DB for parent_uuid and slot are actually cast to string at some point (either the DB layer, or SQL content entity storage, or Entity Field API, or …), and that's how they end up being exported wrong?

Note that I actually can get validation errors to occur, for example doing

diff --git a/tests/fixtures/xb-page-with-data.yml b/tests/fixtures/xb-page-with-data.yml
index 97b35785c..216b7041e 100644
--- a/tests/fixtures/xb-page-with-data.yml
+++ b/tests/fixtures/xb-page-with-data.yml
@@ -19,7 +19,7 @@ default:
       inputs:
         width:
           sourceType: 'static:field_item:list_integer'
-          value: 50
+          value: 40
           expression: ℹ︎list_integer␟value
           sourceTypeSettings:
             storage:

results in:

1) Drupal\Tests\experience_builder\Functional\DefaultContentImportTest::testImportDefaultContentWithXbData
Drupal\Core\DefaultContent\InvalidEntityException: /Users/wim.leers/core/modules/contrib/experience_builder/tests/src/Functional/../../fixtures/xb-page-with-data.yml: components.0.inputs.16176e0b-8197-40e3-ad49-48f1b6e9a7f9.width=Does not have a value in the enumeration [25,33,50,66,75]. The provided value is: "40".

So that means

Worse: the Recipes default content import functionality apparently did not report a validation error?! 😱

is a different problem, and it's a beta-blocking one.

Extracted that to 📌 Tighten validation of `parent_uuid` and `slot` on XB fields to match the strictness of config Active .

Per #3526818-5: Tighten validation of `parent_uuid` and `slot` on XB fields to match the strictness of config → .

✨ Content templates, part 3b: store exposed slot subtrees on individual entities Active adds an array_filter to ComponentTreeItem::getValue that would also have resolved this

Cool, then maybe this issue will be just about test coverage :)