> Now... would a unit test have found that? You have to know exactly what you'd be looking for first. The test would have to be smarter than the person writing the code.
This is a textbook example of something that property based testing can catch. Yes, the tests are smarter than the person that wrote the code. At least, smarter in a different way or maybe it’s that the people who wrote the property based testing framework are super smart.
Look up QuickCheck for the OG or property based testing + your language.
I don’t exactly understand your bug, but the way it would work is something like you’d make some generators that create night stays and rates and put those together into a bill. Then you test the property that the number of line items on the bill is the number of nights + number of discounts (or whatever is right). It will search to break this property and if it breaks it, find a minimal case. Seriously check it out, it’s perfect for this sort of thing.
This is a textbook example of something that property based testing can catch. Yes, the tests are smarter than the person that wrote the code. At least, smarter in a different way or maybe it’s that the people who wrote the property based testing framework are super smart.
Look up QuickCheck for the OG or property based testing + your language.
I don’t exactly understand your bug, but the way it would work is something like you’d make some generators that create night stays and rates and put those together into a bill. Then you test the property that the number of line items on the bill is the number of nights + number of discounts (or whatever is right). It will search to break this property and if it breaks it, find a minimal case. Seriously check it out, it’s perfect for this sort of thing.