FIX: Ensure allowed_tags and allowed_tag_groups can be removed (#16454)

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

@@ -218,14 +218,8 @@ const Category = RestModel.extend({
         all_topics_wiki: this.all_topics_wiki,
         allow_unlimited_owner_edits_on_first_post: this
           .allow_unlimited_owner_edits_on_first_post,
-        allowed_tags:
+        allowed_tags: this.allowed_tags,
-          this.allowed_tags && this.allowed_tags.length > 0
+        allowed_tag_groups: this.allowed_tag_groups,
-            ? this.allowed_tags
-            : null,
-        allowed_tag_groups:
-          this.allowed_tag_groups && this.allowed_tag_groups.length > 0
-            ? this.allowed_tag_groups
-            : null,
         allow_global_tags: this.allow_global_tags,
         required_tag_groups: this.required_tag_groups,
         sort_order: this.sort_order,

app/assets/javascripts/discourse/tests/acceptance/category-edit-test.js

@@ -10,6 +10,7 @@ import DiscourseURL from "discourse/lib/url";
 import selectKit from "discourse/tests/helpers/select-kit-helper";
 import sinon from "sinon";
 import { test } from "qunit";
+import pretender from "discourse/tests/helpers/create-pretender";
 
 acceptance("Category Edit", function (needs) {
   needs.user();
@@ -95,6 +96,48 @@ acceptance("Category Edit", function (needs) {
 
     await click("#save-category");
     assert.strictEqual(count(".required-tag-group-row"), 1);
+
+    await click(".delete-required-tag-group");
+    assert.strictEqual(count(".required-tag-group-row"), 0);
+
+    await click("#save-category");
+    assert.strictEqual(count(".required-tag-group-row"), 0);
+  });
+
+  test("Editing allowed tags and tag groups", async function (assert) {
+    await visit("/c/bug/edit/tags");
+
+    const allowedTagChooser = selectKit("#category-allowed-tags");
+    await allowedTagChooser.expand();
+    await allowedTagChooser.selectRowByValue("monkey");
+
+    const allowedTagGroupChooser = selectKit("#category-allowed-tag-groups");
+    await allowedTagGroupChooser.expand();
+    await allowedTagGroupChooser.selectRowByValue("TagGroup1");
+
+    await click("#save-category");
+
+    const payload = JSON.parse(
+      pretender.handledRequests[pretender.handledRequests.length - 1]
+        .requestBody
+    );
+    assert.deepEqual(payload.allowed_tags, ["monkey"]);
+    assert.deepEqual(payload.allowed_tag_groups, ["TagGroup1"]);
+
+    await allowedTagChooser.expand();
+    await allowedTagChooser.deselectItemByValue("monkey");
+
+    await allowedTagGroupChooser.expand();
+    await allowedTagGroupChooser.deselectItemByValue("TagGroup1");
+
+    await click("#save-category");
+
+    const removePayload = JSON.parse(
+      pretender.handledRequests[pretender.handledRequests.length - 1]
+        .requestBody
+    );
+    assert.deepEqual(removePayload.allowed_tags, []);
+    assert.deepEqual(removePayload.allowed_tag_groups, []);
   });
 
   test("Index Route", async function (assert) {