Signs it is time to revisit automated testing

The advice here is unglamorous, which is probably why it gets skipped. A few signals that automated testing is due some attention.

Code gets read far more often than it gets written, and usually by someone with less context than the author had. It rarely shows up as a line item, which is exactly why it slips.

The signals

• Nobody can say when it was last reviewed
• The answer depends on who you ask
• Tests are how you change things without fear
• Cover the paths that lose money if they break

Where to start

A slow test suite is a suite nobody runs. The reasoning matters more than the rule, because the rule has exceptions. If it only works because one person remembers to do something, it does not work yet.

How to tell if yours is fine

The question is rarely whether something can be built, but what it costs to keep running afterwards. Three things worth confirming about automated testing before you move on:

• Someone can say what the current setup is without going to look
• Cover the paths that lose money if they break — and you know whether that is true here
• There is a way to tell whether the last change to this helped

The point is not perfection, it is knowing which of these you have consciously chosen to skip.