Issue #3517317 by penyaskito, larowlan: SDC slots not being validated against json config schema

(cherry picked from commit 96c70753fe)

core/assets/schemas/v1/metadata-full.schema.json

@@ -5,7 +5,7 @@
     "slotDefinition": {
       "type": "object",
       "patternProperties": {
-        "^[a-zA-Z0-9_-]$": {
+        "^[a-zA-Z0-9_-]+$": {
           "type": "object",
           "properties": {
             "title": {

core/assets/schemas/v1/metadata.schema.json

@@ -5,7 +5,7 @@
     "slotDefinition": {
       "type": "object",
       "patternProperties": {
-        "^[a-zA-Z0-9_-]$": {
+        "^[a-zA-Z0-9_-]+$": {
           "type": "object",
           "properties": {
             "title": {

core/tests/Drupal/Tests/Core/Theme/Component/ComponentValidatorTest.php

@@ -102,6 +102,22 @@ class ComponentValidatorTest extends TestCase {
     // allowed as the allowed type.
     $cta_with_non_string_prop_type['props']['properties']['text']['type'] = ['string', []];
     yield 'non string type (Array)' => [$cta_with_non_string_prop_type];
+
+    $cta_with_invalid_slot_type = $valid_cta;
+    $cta_with_invalid_slot_type['slots'] = [
+      'valid_slot' => [
+        'title' => 'Valid slot',
+        'description' => 'Valid slot description',
+      ],
+      'invalid_slot' => [
+        'title' => [
+          'hello' => 'Invalid slot',
+          'world' => 'Invalid slot',
+        ],
+        'description' => 'Title must be string',
+      ],
+    ];
+    yield 'invalid slot (type)' => [$cta_with_invalid_slot_type];
   }
 
   /**