BDD for financial calculations: Excel vs. Given-When-Then, or both?
This session describes how to use Excel combined with SpecFlow to fulfill the requirements for calculations based on project experience.
For calculations the key examples are usually given as input-output tables that describe what expected calculation result the system should provide for the different input figures. As for these applications even small mistakes can quickly cause big losses, you better describe them in a way that both the business and the development team can understand them.
In Given-When-Then based BDD frameworks, like Cucumber or SpecFlow, you normally use Scenario Outlines for describing these. But are we sure that this is the best? Is this really the best way? Have you ever struggled with formatting big gherkin tables, hunting number precision issues or spending hours of recalculating the input-output tables?
In our projects most of the stakeholders use and like Excel for describing these and they are masters in doing this. Excel seems to be their DSL, so let's try to use it for generating automated tests!
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