From 09a6c1f3a608d75b4bb90e54daf68a065562797a Mon Sep 17 00:00:00 2001
From: Nat <natalie.tay@discourse.org>
Date: Fri, 26 Dec 2025 18:34:34 +0800
Subject: [PATCH 1/2] DEV: Update tag_id usage to tag_name where a tag's name
 is referenced

---
 .discourse-compatibility                       |  1 +
 .../discourse/services/topic-thumbnails.js     | 18 +++++++++---------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/.discourse-compatibility b/.discourse-compatibility
index ca07b14..c350ce6 100644
--- a/.discourse-compatibility
+++ b/.discourse-compatibility
@@ -1,3 +1,4 @@
+< 2025.12.0-latest: 9bca25f668deeec39c7096c15779e54af5a66ff1
 < 3.6.0.beta1-dev: f3249a84e2857ba7312888566d1fd8e4aa35f0cd
 < 3.5.0.beta5-dev: 858687bdd6438fa8f638b5048dd1999c89277fe7
 < 3.5.0.beta3-dev: fcb4a13c4b5a1b340de3d60f6b4a0d0a1bf37bbc
diff --git a/javascripts/discourse/services/topic-thumbnails.js b/javascripts/discourse/services/topic-thumbnails.js
index 8ef460a..3c92e8d 100644
--- a/javascripts/discourse/services/topic-thumbnails.js
+++ b/javascripts/discourse/services/topic-thumbnails.js
@@ -57,13 +57,13 @@ export default class TopicThumbnailService extends Service {
   }
 
   @dependentKeyCompat
-  get viewingTagId() {
-    return this.discovery.tag?.id;
+  get viewingTagName() {
+    return this.discovery.tag?.name;
   }
 
   @discourseComputed(
     "viewingCategoryId",
-    "viewingTagId",
+    "viewingTagName",
     "router.currentRoute.metadata.customThumbnailMode",
     "isTopicListRoute",
     "isTopicRoute",
@@ -71,7 +71,7 @@ export default class TopicThumbnailService extends Service {
   )
   displayMode(
     viewingCategoryId,
-    viewingTagId,
+    viewingTagName,
     customThumbnailMode,
     isTopicListRoute,
     isTopicRoute,
@@ -90,15 +90,15 @@ export default class TopicThumbnailService extends Service {
       return "grid";
     } else if (listCategories.includes(viewingCategoryId)) {
       return "list";
-    } else if (masonryTags.includes(viewingTagId)) {
+    } else if (masonryTags.includes(viewingTagName)) {
       return "masonry";
-    } else if (minimalGridTags.includes(viewingTagId)) {
+    } else if (minimalGridTags.includes(viewingTagName)) {
       return "minimal-grid";
-    } else if (blogStyleTags.includes(viewingTagId)) {
+    } else if (blogStyleTags.includes(viewingTagName)) {
       return "blog-style";
-    } else if (gridTags.includes(viewingTagId)) {
+    } else if (gridTags.includes(viewingTagName)) {
       return "grid";
-    } else if (listTags.includes(viewingTagId)) {
+    } else if (listTags.includes(viewingTagName)) {
       return "list";
     } else if (isTopicRoute && settings.suggested_topics_mode) {
       return settings.suggested_topics_mode;

From d7551df35e302fdff3095a6e84aa41878e38082c Mon Sep 17 00:00:00 2001
From: Nat <natalie.tay@discourse.org>
Date: Fri, 26 Dec 2025 20:47:51 +0800
Subject: [PATCH 2/2] add test that will pass after merge

---
 test/acceptance/tag-thumbnail-mode-test.js | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 test/acceptance/tag-thumbnail-mode-test.js

diff --git a/test/acceptance/tag-thumbnail-mode-test.js b/test/acceptance/tag-thumbnail-mode-test.js
new file mode 100644
index 0000000..86461fd
--- /dev/null
+++ b/test/acceptance/tag-thumbnail-mode-test.js
@@ -0,0 +1,32 @@
+import { getOwner } from "@ember/owner";
+import { visit } from "@ember/test-helpers";
+import { test } from "qunit";
+import { cloneJSON } from "discourse/lib/object";
+import discoveryFixture from "discourse/tests/fixtures/discovery-fixtures";
+import { acceptance } from "discourse/tests/helpers/qunit-helpers";
+
+acceptance("topic thumbnails | tag route integration", function (needs) {
+  needs.settings({ tagging_enabled: true });
+
+  needs.pretender((server, helper) => {
+    server.get("/tag/important/l/latest.json", () => {
+      return helper.response(
+        cloneJSON(discoveryFixture["/tag/important/l/latest.json"])
+      );
+    });
+  });
+
+  test("service correctly identifies tag name from route", async function (assert) {
+    await visit("/tag/important");
+
+    const topicThumbnailsService = getOwner(this).lookup(
+      "service:topic-thumbnails"
+    );
+
+    assert.strictEqual(
+      topicThumbnailsService.viewingTagName,
+      "important",
+      "viewingTagName returns the tag name (not id) from the route"
+    );
+  });
+});