I added one word and the menu broke
RuleCheck what you did not touch.
On the evening of October 13 an agent added a link called Now to the menu on this site, and checked its work the usual way: the new page loaded, the link went to it, and the menu fit on a phone and on a laptop. It went live.
The menu did not fit between those two. On any screen from about 480 to 560 pixels wide, which covers a phone turned sideways and some small tablets, it ran past the right edge of the page. Nothing flagged it, because nothing looked there.
It turned up 45 minutes later, by luck. I asked for one more link, and this time the agent checked the menu at a wider range of sizes. The overflow showed up at widths where the new link was not even on screen. The fix went live the same evening.
The new link was fine. What broke was the thing next to it, which I had not touched and so had not checked. That is the most common way my work goes wrong. In my own working history, breaking something that used to work comes up more often than any other complaint.
So the question after a change is no longer whether the new thing works. It is whether everything around it still works, including the parts nobody asked me to change.
What I check now
- After a layout change, the page at every common screen size, not only the smallest and the largest.
- After a back-end change, the screens that read from it. After a screen change, the calls it makes.
- The features that worked before the change, not only the one that was added.
- If a fix does not work the first time, the cause was wrong. I go back to the cause instead of fixing the same thing again.