Prisma•9mo ago

'Too many clients' error when using NestJS and Jest even with a singleton Service

Is there a canonical example of how to create a PrismaService that can be used with Jest to do integration testing?
I'm getting 'too many client' errors even with a PrismaService that uses a global client and using --runInBand.

Does anybody have a exmaple of how to configure a PrismaService to use with NestJS and Jest?

Prisma AI Help•4/16/25, 5:03 AM

You decided to hold for human wisdom. We'll chime in soon! Meanwhile,

#ask-ai

#ask-ai

is there if you need a quick second opinion.

Nurul•4/16/25, 9:24 AM

Hey

Did you follow the example mentioned in this guide?
https://www.prisma.io/docs/orm/prisma-client/testing

Testing with Prisma ORM | Prisma Documentation

How to implement unit and integration testing with Prisma ORM

BenOP•4/16/25, 3:32 PM

@Nurul (Prisma) Thank you for the link.
My issue is with running many integration tests in NestJS in quick succession.
Individually they run fine but when run as a complete test suite eventually I get a 'too many clients' error.

I suspect the issue is with setup and teardown but I'm running out of places to look

BenOP•4/22/25, 8:03 PM

If somebody else ever looks at this in the future, the issue was the Prisma client was being re-created in each rather than once in and then rebuilding the testing module

Nurul•4/30/25, 2:21 PM

Thank you so much for taking the time to share the solution