FIX: Use serialized subcategories in subcategory-with-featured-topics (#26718)

app/assets/javascripts/discourse/app/components/subcategories-with-featured-topics.hbs

@@ -13,7 +13,7 @@
       </tr>
     </thead>
     <tbody aria-labelledby="categories-only-category">
-      {{#each category.subcategories as |subCategory|}}
+      {{#each category.serializedSubcategories as |subCategory|}}
         <ParentCategoryRow @category={{subCategory}} @showTopics={{true}} />
       {{else}}
         {{! No subcategories... so just show the parent to avoid confusion }}

app/assets/javascripts/discourse/app/models/category.js

@@ -6,6 +6,7 @@ import { NotificationLevels } from "discourse/lib/notification-levels";
 import PermissionType from "discourse/models/permission-type";
 import RestModel from "discourse/models/rest";
 import Site from "discourse/models/site";
+import Topic from "discourse/models/topic";
 import User from "discourse/models/user";
 import { getOwnerWithFallback } from "discourse-common/lib/get-owner";
 import getURL from "discourse-common/lib/get-url";
@@ -459,6 +460,11 @@ export default class Category extends RestModel {
     return this.site.categories.filterBy("parent_category_id", this.id);
   }
 
+  @computed("subcategory_list")
+  get serializedSubcategories() {
+    return this.subcategory_list?.map((c) => Category.create(c));
+  }
+
   @discourseComputed("required_tag_groups", "minimum_required_tags")
   minimumRequiredTags() {
     if (this.required_tag_groups?.length > 0) {
@@ -759,7 +765,9 @@ export default class Category extends RestModel {
   @discourseComputed("topics")
   featuredTopics(topics) {
     if (topics && topics.length) {
-      return topics.slice(0, this.num_featured_topics || 2);
+      return topics
+        .slice(0, this.num_featured_topics || 2)
+        .map((t) => Topic.create(t));
     }
   }
 

app/assets/javascripts/discourse/tests/fixtures/discovery-fixtures.js

@@ -1554,6 +1554,27 @@ export default {
           description_excerpt:
             "Discussion about features or potential features of Discourse: how they work, why they work, etc.",
           featured_user_ids: [1917, 4385, 2072, 32, 4263],
+          subcategory_list: [
+            {
+              id: 26,
+              name: "spec",
+              color: "33B0B0",
+              text_color: "FFFFFF",
+              slug: "spec",
+              topic_count: 20,
+              post_count: 278,
+              description:
+                "My idea here is to have mini specs for features we would like built but have no bandwidth to build",
+              description_text:
+                "My idea here is to have mini specs for features we would like built but have no bandwidth to build",
+              topic_url: "/t/about-the-spec-category/13965",
+              read_restricted: false,
+              permission: 1,
+              parent_category_id: 2,
+              notification_level: null,
+              background_url: null,
+            },
+          ],
           topics: [
             {
               id: 11997,