This is a fake API for retrieving a "report". It consists of:
- A main getReport unit - our test subject
- Two dependencies the subject delegates to:
- loadReportData to get report data from some data store
- generateReport to create a report from the source data
Using vitest along with testdouble and testdouble-vitest to inject fake versions of our dependencies, we wrote a test suite to design how our subject delegates its work to its dependencies.