Last week I changed one line in a module that decides which rows make it into a dataset. A threshold, 10 to 5.
Nothing broke. The tests passed — they test the function, and the function was correct. The CSV in _output/ from the previous run kept sitting there. Three analysis scripts kept reading it. And a write-up I had already finished quoted a number computed from it.
That number was now wrong. Nothing in my project could have told me.
Why nothing catches this
Run through the tools you'd expect to help:
