FIX: Welcome topic should be hidden on the /categories page as well (#18869)

* FIX: Welcome topic should be hidden on the /categories page as well

* add tests

app/controllers/categories_controller.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 class CategoriesController < ApplicationController
+  include TopicQueryParams
 
   requires_login except: [:index, :categories_and_latest, :categories_and_top, :show, :redirect, :find_by_slug, :visible_groups]
 
@@ -291,6 +292,8 @@ class CategoriesController < ApplicationController
       per_page: CategoriesController.topics_per_page,
       no_definitions: true,
     }
+
+    topic_options.merge!(build_topic_list_options)
     style = SiteSetting.desktop_category_page_style
     topic_options[:order] = 'created' if style == "categories_and_latest_topics_created_date"
 

spec/requests/categories_controller_spec.rb

@@ -235,6 +235,54 @@ RSpec.describe CategoriesController do
       end
     end
 
+    describe "welcome topic" do
+      fab!(:category) { Fabricate(:category) }
+      fab!(:topic1) { Fabricate(:topic, category: category, created_at: 5.days.ago, updated_at: Time.now, bumped_at: Time.now) }
+      fab!(:topic2) { Fabricate(:topic, category: category, created_at: 2.days.ago, bumped_at: 2.days.ago) }
+      fab!(:topic3) { Fabricate(:topic, category: category, created_at: 1.day.ago, bumped_at: 1.day.ago) }
+      fab!(:welcome_topic) { Fabricate(:topic) }
+      fab!(:post) { Fabricate(:post, topic: welcome_topic) }
+
+      before do
+        SiteSetting.desktop_category_page_style = "categories_and_latest_topics"
+        SiteSetting.welcome_topic_id = welcome_topic.id
+        SiteSetting.editing_grace_period = 1.minute.to_i
+        SiteSetting.bootstrap_mode_enabled = true
+      end
+
+      it "is hidden for non-admins" do
+        get "/categories_and_latest.json"
+        expect(response.status).to eq(200)
+        expect(response.parsed_body['topic_list']['topics'].map { |t| t["id"] }).not_to include(welcome_topic.id)
+      end
+
+      it "is shown to non-admins when there is an edit" do
+        post.revise(post.user, { raw: "#{post.raw}2" }, revised_at: post.updated_at + 2.minutes)
+        post.reload
+        expect(post.version).to eq(2)
+
+        get "/categories_and_latest.json"
+        expect(response.status).to eq(200)
+        expect(response.parsed_body['topic_list']['topics'].map { |t| t["id"] }).to include(welcome_topic.id)
+      end
+
+      it "is hidden to admins" do
+        sign_in(admin)
+
+        get "/categories_and_latest.json"
+        expect(response.status).to eq(200)
+        expect(response.parsed_body['topic_list']['topics'].map { |t| t["id"] }).not_to include(welcome_topic.id)
+      end
+
+      it "is shown to users when bootstrap mode is disabled" do
+        SiteSetting.bootstrap_mode_enabled = false
+
+        get "/categories_and_latest.json"
+        expect(response.status).to eq(200)
+        expect(response.parsed_body['topic_list']['topics'].map { |t| t["id"] }).to include(welcome_topic.id)
+      end
+    end
+
     it 'includes subcategories and topics by default when view is subcategories_with_featured_topics' do
       SiteSetting.max_category_nesting = 3
       subcategory = Fabricate(:category, user: admin, parent_category: category)