FEATURE: Include advanced search option to include unlisted topics in the results (#27958)

---------

Co-authored-by: Régis Hanol <regis@hanol.fr>

lib/search.rb

@@ -935,6 +935,9 @@ class Search
             @search_context = user
           end
 
+          nil
+        elsif word =~ /\Ainclude:(invisible|unlisted)\z/i
+          @include_invisible = true
           nil
         else
           found ? nil : word
@@ -1113,7 +1116,7 @@ class Search
     end
 
     is_topic_search = @search_context.present? && @search_context.is_a?(Topic)
-    posts = posts.where("topics.visible") unless is_topic_search
+    posts = posts.where("topics.visible") unless is_topic_search || @include_invisible
 
     if type_filter == "private_messages" || (is_topic_search && @search_context.private_message?)
       posts =

spec/lib/search_spec.rb

@@ -2541,6 +2541,23 @@ RSpec.describe Search do
     end
   end
 
+  describe "include:invisible / include:unlisted" do
+    it "allows including invisible topics in the results" do
+      topic = Fabricate(:topic, title: "I am testing a search", visible: false)
+      post = Fabricate(:post, topic: topic, raw: "this is the first post", post_number: 1)
+      _post2 = Fabricate(:post, topic: topic, raw: "this is the second post", post_number: 2)
+
+      results = Search.execute("testing include:invisible")
+      expect(results.posts.map(&:id)).to eq([post.id])
+
+      results = Search.execute("testing include:unlisted")
+      expect(results.posts.map(&:id)).to eq([post.id])
+
+      results = Search.execute("testing")
+      expect(results.posts).to eq([])
+    end
+  end
+
   describe "ignore_diacritics" do
     before { SiteSetting.search_ignore_accents = true }
     let!(:post1) { Fabricate(:post, raw: "สวัสดี Rágis hello") }