Disable additionalProperties in slots, props in SDC json schema

Great find! 🤩

The best part: this should not require any update path, nor is it a BC break; this is just tightening SDC's existing JSON Schema! 👏

So we can do this for slots, because we have our own slotDefinition, but not for props, that are using http://json-schema.org/draft-04/schema#: see https://github.com/orgs/json-schema-org/discussions/502#discussioncommen....

Maybe we can use allOf instead of $ref here.

Added 📌 Twig disallows dashes in variable names, so SDC should disallow it in prop names Active as related.

allOf didn't work, as this is an object not an array, so reverted that.

Added a test with invalid slot name, and apparently additionalProperties is ignored, becase this test fails to trigger the expected exception.

Type was never defined in schema for slots, but some components were using it.

I opted for removing it, as slots should be any html fragment, and we aren't validating them anyway.

Even if this is not a BC break technically, it would be in practice, as the components I had to change in core show.

So probably a change record won't hurt, and we might not want to cherry-pick to 11.1.

Hi Penyakisto,

Thanks you for this quick proposal.

You added additionalProperties twice, at the upper slot names level, and at the lower slot definition level:

    "slotDefinition": {
      "type": "object",
+      "additionalProperties": false,
      "patternProperties": {
        "^[a-zA-Z0-9_-]+$": {
          "type": "object",
+          "additionalProperties": false,

The higher level constraint is the main task of this ticket.

Adding the lower level constraint was useful:

• to detect some errors in Core components, where you removed the unexpected type property
• to add the forgotten required property to the schema

But I am still not sure it is a constraint we need to add in this MR (while keeping the other changes anyway). I will need to think a bit about that ;)