FIX: Pass category param on /tags/intersection (#23352)

app/assets/javascripts/discourse/app/controllers/tags-intersection.js

@@ -0,0 +1,13 @@
+import { queryParams } from "discourse/controllers/discovery-sortable";
+import TagShowController from "discourse/controllers/tag-show";
+
+export default class TagsIntersectionController extends TagShowController {
+  constructor() {
+    super(...arguments);
+
+    this.set("queryParams", [
+      ...Object.keys(queryParams),
+      { categoryParam: "category" },
+    ]);
+  }
+}

app/assets/javascripts/discourse/app/routes/tag-show.js

@@ -41,7 +41,7 @@ export default class TagShowRoute extends DiscourseRoute {
   }
 
   beforeModel() {
-    const controller = this.controllerFor("tag.show");
+    const controller = this.controllerFor(this.controllerName);
     controller.setProperties({
       loading: true,
       showInfo: false,
@@ -74,7 +74,7 @@ export default class TagShowRoute extends DiscourseRoute {
       );
     }
 
-    const category = params.category_slug_path_with_id
+    let category = params.category_slug_path_with_id
       ? Category.findBySlugPathWithID(params.category_slug_path_with_id)
       : null;
     const filteredQueryParams = filterQueryParams(
@@ -96,6 +96,13 @@ export default class TagShowRoute extends DiscourseRoute {
       filter += `/${tagId}/l/${topicFilter}`;
     } else if (additionalTags) {
       filter = `tags/intersection/${tagId}/${additionalTags.join("/")}`;
+
+      if (transition.to.queryParams["category"]) {
+        filteredQueryParams["category"] = transition.to.queryParams["category"];
+        category = Category.findBySlugPathWithID(
+          transition.to.queryParams["category"]
+        );
+      }
     } else {
       filter = `tag/${tagId}/l/${topicFilter}`;
     }
@@ -150,7 +157,7 @@ export default class TagShowRoute extends DiscourseRoute {
   setupController(controller, model) {
     const noSubcategories = this.noSubcategories;
 
-    this.controllerFor("tag.show").setProperties({
+    controller.setProperties({
       model: model.tag,
       ...model,
       period: model.list.for_period,
@@ -179,7 +186,7 @@ export default class TagShowRoute extends DiscourseRoute {
     const filterText = I18n.t(
       `filters.${this.navMode.replace("/", ".")}.title`
     );
-    const controller = this.controllerFor("tag.show");
+    const controller = this.controllerFor(this.controllerName);
 
     if (controller.tag?.id) {
       if (controller.category) {
@@ -223,7 +230,7 @@ export default class TagShowRoute extends DiscourseRoute {
     if (this.currentUser?.has_topic_draft) {
       this.openTopicDraft();
     } else {
-      const controller = this.controllerFor("tag.show");
+      const controller = this.controllerFor(this.controllerName);
       this.composer
         .open({
           categoryId: controller.category?.id,
@@ -248,7 +255,7 @@ export default class TagShowRoute extends DiscourseRoute {
 
   @action
   dismissRead(operationType) {
-    const controller = this.controllerFor("tag-show");
+    const controller = this.controllerFor(this.controllerName);
     let options = {
       tagName: controller.tag?.id,
     };

app/assets/javascripts/discourse/app/routes/tags-intersection.js

@@ -1,9 +1,20 @@
+import { queryParams } from "discourse/controllers/discovery-sortable";
 import { buildTagRoute } from "discourse/routes/tag-show";
 
-export default buildTagRoute();
-
 // The tags-intersection route is exactly the same as the tags-show route, but the wildcard at the
 // end of the route (*additional_tags) will cause a match when query parameters are present,
 // breaking all other tags-show routes. Ember thinks the query params are addition tags and should
 // be handled by the intersection logic. Defining tags-intersection as something separate avoids
 // that confusion.
+export default buildTagRoute().extend({
+  controllerName: "tags.intersection",
+
+  init() {
+    this._super(...arguments);
+
+    // The only difference is support for `category` query param.
+    // Other routes include category in the route path.
+    this.set("queryParams", { ...queryParams });
+    this.queryParams["categoryParam"] = { replace: true, refreshModel: true };
+  },
+});

app/assets/javascripts/discourse/tests/acceptance/tags-intersection-test.js

@@ -1,5 +1,6 @@
 import { click, visit } from "@ember/test-helpers";
 import { test } from "qunit";
+import pretender, { response } from "discourse/tests/helpers/create-pretender";
 import {
   acceptance,
   exists,
@@ -11,9 +12,9 @@ acceptance("Tags intersection", function (needs) {
   needs.site({ can_tag_topics: true });
   needs.settings({ tagging_enabled: true });
 
-  needs.pretender((server, helper) => {
-    server.get("/tags/intersection/first/second.json", () => {
-      return helper.response({
+  test("Populate tags when creating new topic", async function (assert) {
+    pretender.get("/tags/intersection/first/second.json", () => {
+      return response({
         users: [],
         primary_groups: [],
         topic_list: {
@@ -27,9 +28,7 @@ acceptance("Tags intersection", function (needs) {
         },
       });
     });
-  });
 
-  test("Populate tags when creating new topic", async function (assert) {
     await visit("/tags/intersection/first/second");
     await click("#create-topic");
 
@@ -40,4 +39,28 @@ acceptance("Tags intersection", function (needs) {
       "populates the tags when clicking 'New topic'"
     );
   });
+
+  test("correctly passes the category filter", async function (assert) {
+    pretender.get("/tags/intersection/sour/tangy.json", (request) => {
+      assert.deepEqual(request.queryParams, { category: "fruits" });
+      assert.step("request");
+
+      return response({
+        users: [],
+        primary_groups: [],
+        topic_list: {
+          can_create_topic: true,
+          draft_key: "new_topic",
+          topics: [{ id: 16, posters: [] }],
+          tags: [
+            { id: 1, name: "second", topic_count: 1 },
+            { id: 2, name: "first", topic_count: 1 },
+          ],
+        },
+      });
+    });
+
+    await visit("/tags/intersection/sour/tangy?category=fruits");
+    assert.verifySteps(["request"]);
+  });
 });