Add system specs for mentions in comments

decidim-core/lib/decidim/core/test/shared_examples/comments_examples.rb

@@ -174,5 +174,45 @@
         end
       end
     end
+
+    describe "mentions" do
+      before do
+        visit resource_path
+
+        within ".add-comment form" do
+          fill_in "add-comment-#{commentable.commentable_type}-#{commentable.id}", with: content
+          click_button "Send"
+        end
+      end
+
+      context "when mentioning a valid user" do
+        let!(:mentioned_user) { create(:user, :confirmed, organization: organization) }
+        let(:content) { "A valid user mention: @#{mentioned_user.nickname}" }
+
+        it "replaces the mention with a link to the user's profile" do
+          expect(page).to have_comment_from(user, "A valid user mention: @#{mentioned_user.nickname}")
+          expect(page).to have_link "@#{mentioned_user.nickname}", href: "/profiles/#{mentioned_user.nickname}"
+        end
+      end
+
+      context "when mentioning an existing user outside current organization" do
+        let!(:mentioned_user) { create(:user, :confirmed, organization: create(:organization)) }
+        let(:content) { "This text mentions a user outside current organization: @#{mentioned_user.nickname}" }
+
+        it "ignores the mention" do
+          expect(page).to have_comment_from(user, "This text mentions a user outside current organization: @#{mentioned_user.nickname}")
+          expect(page).not_to have_link "@#{mentioned_user.nickname}"
+        end
+      end
+
+      context "when mentioning a non valid user" do
+        let(:content) { "This text mentions a @nonexistent user" }
+
+        it "ignores the mention" do
+          expect(page).to have_comment_from(user, "This text mentions a @nonexistent user")
+          expect(page).not_to have_link "@nonexistent"
+        end
+      end
+    end
   end
 end