FIX: Site's top tags not shown for anonymous user (#22219)

When a site does not have `default_navigation_menu_tags`
site setting set, anonymous users should be shown the site's top tags as
a default in the tags section. However, this regressed in 9fad71809c254752479b0faf4f23ba197e742e60
and we ended up showing anonymous users a tags section with only the
`All Tags` section link.

As part of this commit, I have also refactored the QUnit acceptance
tests to system tests which are much easier to work with.

app/assets/javascripts/discourse/tests/acceptance/sidebar-anonymous-tags-section-test.js

@@ -1,84 +0,0 @@
-import { test } from "qunit";
-import { visit } from "@ember/test-helpers";
-import {
-  acceptance,
-  exists,
-  queryAll,
-} from "discourse/tests/helpers/qunit-helpers";
-import Site from "discourse/models/site";
-
-acceptance("Sidebar - Anonymous Tags Section", function (needs) {
-  needs.settings({
-    navigation_menu: "sidebar",
-    suppress_uncategorized_badge: false,
-    tagging_enabled: true,
-  });
-
-  needs.site({
-    top_tags: ["design", "development", "fun"],
-  });
-
-  test("tag section links when site has top tags", async function (assert) {
-    await visit("/");
-
-    const categories = queryAll(
-      ".sidebar-section[data-section-name='tags'] .sidebar-section-link-wrapper[data-tag-name]"
-    );
-
-    assert.strictEqual(categories.length, 3);
-    assert.strictEqual(categories[0].textContent.trim(), "design");
-    assert.strictEqual(categories[1].textContent.trim(), "development");
-    assert.strictEqual(categories[2].textContent.trim(), "fun");
-
-    assert.ok(
-      exists("a.sidebar-section-link[data-link-name='all-tags']"),
-      "all tags link is visible"
-    );
-  });
-
-  test("tag section links when site has default sidebar tags configured", async function (assert) {
-    const site = Site.current();
-    site.set("anonymous_default_navigation_menu_tags", ["random", "meta"]);
-
-    await visit("/");
-
-    const categories = queryAll(
-      ".sidebar-section[data-section-name='tags'] .sidebar-section-link-wrapper"
-    );
-    assert.strictEqual(categories.length, 3);
-    assert.strictEqual(categories[0].textContent.trim(), "random");
-    assert.strictEqual(categories[1].textContent.trim(), "meta");
-
-    assert.ok(
-      exists("a.sidebar-section-link[data-link-name='all-tags']"),
-      "all tags link is visible"
-    );
-  });
-
-  test("tag section is hidden when tagging is disabled", async function (assert) {
-    this.siteSettings.tagging_enabled = false;
-
-    await visit("/");
-
-    assert.ok(
-      !exists(".sidebar-section[data-section-name='tags']"),
-      "section is not visible"
-    );
-  });
-
-  test("tag section is hidden when anonymous has no visible top tags and site has not default sidebar tags configured", async function (assert) {
-    const site = Site.current();
-
-    site.setProperties({
-      top_tags: [],
-      anonymous_default_navigation_menu_tags: [],
-    });
-
-    await visit("/");
-
-    assert.ok(
-      !exists(".sidebar-section[data-section-name='tags']"),
-      "section is not visible"
-    );
-  });
-});

app/serializers/site_serializer.rb

@@ -251,12 +251,14 @@ class SiteSerializer < ApplicationSerializer
   end
 
   def anonymous_default_navigation_menu_tags
+    @anonymous_default_navigation_menu_tags ||=
       SiteSetting.default_navigation_menu_tags.split("|") - DiscourseTagging.hidden_tag_names(scope)
   end
 
   def include_anonymous_default_navigation_menu_tags?
     scope.anonymous? && !SiteSetting.legacy_navigation_menu? && SiteSetting.tagging_enabled &&
-      SiteSetting.default_navigation_menu_tags.present?
+      SiteSetting.default_navigation_menu_tags.present? &&
+      anonymous_default_navigation_menu_tags.present?
   end
 
   def anonymous_sidebar_sections

spec/system/page_objects/components/sidebar.rb

@@ -83,6 +83,27 @@ module PageObjects
         has_section?("Tags")
       end
 
+      def has_no_tags_section?
+        has_no_section?("Tags")
+      end
+
+      def has_all_tags_section_link?
+        has_section_link?(I18n.t("js.sidebar.all_tags"))
+      end
+
+      def has_tags_section_links?(tags)
+        section_selector = ".sidebar-section[data-section-name='tags']"
+        tag_names = tags.map(&:name)
+
+        has_css?(
+          "#{section_selector} .sidebar-section-link-wrapper[data-tag-name]",
+          count: tag_names.length,
+        ) &&
+          all("#{section_selector} .sidebar-section-link-wrapper[data-tag-name]").all? do |row|
+            tag_names.include?(row["data-tag-name"].to_s)
+          end
+      end
+
       def has_no_section?(name)
         find(SIDEBAR_WRAPPER_SELECTOR).has_no_button?(name)
       end

spec/system/viewing_sidebar_as_anonymous_user_spec.rb

@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+describe "Viewing sidebar as anonymous user", type: :system do
+  fab!(:tag1) { Fabricate(:tag).tap { |tag| Fabricate.times(1, :topic, tags: [tag]) } }
+  fab!(:tag2) { Fabricate(:tag).tap { |tag| Fabricate.times(2, :topic, tags: [tag]) } }
+  fab!(:tag3) { Fabricate(:tag).tap { |tag| Fabricate.times(3, :topic, tags: [tag]) } }
+  fab!(:tag4) { Fabricate(:tag).tap { |tag| Fabricate.times(2, :topic, tags: [tag]) } }
+  fab!(:tag5) { Fabricate(:tag).tap { |tag| Fabricate.times(2, :topic, tags: [tag]) } }
+  fab!(:tag6) { Fabricate(:tag).tap { |tag| Fabricate.times(1, :topic, tags: [tag]) } }
+
+  let(:sidebar) { PageObjects::Components::Sidebar.new }
+
+  describe "when viewing the tags section" do
+    it "should not display the tags section when tagging has been disabled" do
+      SiteSetting.tagging_enabled = false
+
+      visit("/latest")
+
+      expect(sidebar).to have_no_tags_section
+    end
+
+    it "should not display the tags section when site has no top tags and `default_navigation_menu_tags` site setting has not been set" do
+      Tag.delete_all
+
+      visit("/latest")
+
+      expect(sidebar).to have_no_tags_section
+    end
+
+    it "should display the site's top tags when `default_navigation_menu_tags` site setting has not been set" do
+      visit("/latest")
+
+      expect(sidebar).to have_tags_section
+      expect(sidebar).to have_all_tags_section_link
+      expect(sidebar).to have_tags_section_links([tag1, tag2, tag3, tag4, tag5])
+    end
+
+    it "should display the site's top tags when `default_navigation_menu_tags` site setting has been set but the tags configured are hidden to the user" do
+      SiteSetting.default_navigation_menu_tags = "#{tag5.name}"
+      Fabricate(:tag_group, permissions: { "staff" => 1 }, tag_names: [tag5.name])
+
+      visit("/latest")
+
+      expect(sidebar).to have_tags_section
+      expect(sidebar).to have_all_tags_section_link
+      expect(sidebar).to have_tags_section_links([tag1, tag2, tag3, tag4, tag6])
+    end
+
+    it "should display the tags configured in `default_navigation_menu_tags` site setting when it has been set" do
+      SiteSetting.default_navigation_menu_tags = "#{tag3.name}|#{tag4.name}"
+
+      visit("/latest")
+
+      expect(sidebar).to have_tags_section
+      expect(sidebar).to have_all_tags_section_link
+      expect(sidebar).to have_tags_section_links([tag3, tag4])
+    end
+  end
+end