I'm wondering how to start, I'm having trouble getting the dependency injection working.

I followed the example of on prisma, but I don't know how to proceed further. NestJS gives me the error 'Nest can't resolve dependencies of the CustomService. Please make sure that the argument PrismaService at index [0] is available in the RootTestModule context'. But trying to provide the Mock PrismaClient there does not work.

Aah found an example here: https://github.com/jmcdo29/testing-nestjs/blob/master/apps/prisma-sample/src/cat/cat.service.spec.ts