allowed user pings to be made to users with negative ids

Author: Oaphi

app/models/comment.rb

@@ -4,7 +4,7 @@ class Comment < ApplicationRecord
   include SoftDeletable
   include Timestamped
 
-  USER_PING_REG_EXP = /@#(\d+)/
+  USER_PING_REG_EXP = /@#(-?\d+)/
 
   scope :by, ->(user) { where(user: user) }
 

test/models/comment_test.rb

@@ -19,4 +19,18 @@ class CommentTest < ActiveSupport::TestCase
     assert_equal posts(:question_one).id, comments(:one).root.id
     assert_equal posts(:question_one).id, comments(:on_answer).root.id
   end
+
+  test 'USER_PING_REG_EXP should correctly match user mentions' do
+    valid_mentions = ["@##{User.system.id}", "@##{users(:standard_user).id}"]
+
+    valid_mentions.each do |mention|
+      assert Comment::USER_PING_REG_EXP.match?(mention)
+    end
+
+    invalid_mentions = ['', '@', '@#', '@#system', "@##{users(:standard_user).name}"]
+
+    invalid_mentions.each do |mention|
+      assert_not Comment::USER_PING_REG_EXP.match?(mention)
+    end
+  end
 end