A Green API Is Not a Working Page

This story was originally published on HackerNoon at: https://hackernoon.com/a-green-api-is-not-a-working-page. Five production bugs that passed every API check while the page was broken — including an HTML escape that killed the click handler on a third of the cards. Check more stories related to programming at: https://hackernoon.com/c/programming. You can also check exclusive content about #javascript, #webdev, #debugging, #frontend, #web-analytics, #production-bugs, #ecommerce, #observability, and more. This story was written by: @ohadfarkash. Learn more about this writer by checking @ohadfarkash's about page, and for more stories, please visit hackernoon.com. Every endpoint returned 200. Every latency measurement was green. Meanwhile a third of the product cards had a dead click handler, a call-to-action had been inert long enough for a shopper to click it five times in 26 seconds on a session recording, and product images sat fully loaded inside cards that were one pixel tall. None of it was visible from the server, because a handler that never compiles leaves no trace there. Here is each bug, the measurement that actually found it, and the assertion I now write instead.