Scenarios with specumber

What a scenario is for

A scenario has two readers. One needs to know what the system does and has not opened the source. The other is the run that proves the system still does it. A scenario that satisfies only the second is half written: it passes, and it says nothing.

So a feature file is read as documentation first. Someone who needs to call the thing should be able to read it and know what to send, what comes back, and what happens when it goes wrong — without the implementation open beside them. What no scenario states is not part of the contract, and nothing else says it is.

This is also the order to work in: write the scenario, watch it fail for the reason you expect, then write the code, then watch it pass. A scenario that has never failed has not been shown to test anything.

Writing the scenario