Back when we were using Jasmine, testing functions (such as expect, describe, it, etc.) were global and "magically injected" by the test runner. Jest did the same thing, which made it easier to switch.
I discovered that Jest 26 introduced @jest/globals, which makes it possible to explicitly import testing functions. Since vitest requires such imports, opting-in gradually to @jest/globals will make our work easier when switching to vitest.