CheckUser code currently doesn't support unit testing. This feature should be added, and alongside it a test data set should also be generated.

The test data set can be extended and repurposed, such that it can be used for creating any additional extensions (e.g. a JS code that uses CU tool via API). Having a relatively extensive set of test data can be extremely beneficial.

The task is created in reaction to notable support for this idea on the cu-l listserv. One of the users on the listserv also made suggestions about what the test data should contain, which is pasted below:

• Users
• Sample users and anons whose edits are to be checked
• Sample CU users whose names appear in log and who can run tests
  • with admin rights
  • without admin rights (different interface)
  • special: oversight, steward -- is it neccessary?
• Sample non-CU users who fail to use the tool
• Users with constant or almost constant IP and UA for a simple case
• Useres who often change their data (both users with dynamic IP from an ISO with multiple domains and sofisticated vandals)
• Multiple users from same IP

• IPs
  • IPv4
  • IPv6
  • Some similar from a same domain
  • Some different
  • Blocked, previously blocked and not blocked

• User agents
  • Common from a few operating systems and browsers (useful to keep up-to-date)
  • A few complicated ones
  • Some known bots (AWB or Pywikibot)
  • Fake

• Edits
  • Logged-in
  • IP
  • From behind proxy / open proxy
  • Newr than 3 months
  • Older than 3 months

• Edit summaries and check reasons -- I am not sure if they are impoertant for testing and experimenting
• Pages of course that were edited -- I don't hink this needs extra considerations