Negative Testing: Broad Properties
Learn about the concept of negative testing and how broad properties can help find bugs in the code that regular properties would not.
We'll cover the following...
Negative tests
An interesting aspect of the code and tests we have written so far is that the list of items being bought is generated through the list of supported items. Designing the test case from the price list shows a lack of tests looking for unexpected use cases. Our tests are positive, happy-path tests, validating that everything is operating as it should. Negative tests, by comparison, try to specifically exercise underspecified scenarios to find what happens in less happy paths.
Our current properties are good. We don’t want to modify them or make them more complex. Instead, we’ll write a few broad properties that test more general properties of the code and see if the requirements we had in place are actually consistent. On their own, ...