Prisma ORM v7 ships as an ES Module which is creating compatibility issues with NestJS

[RareParsec]

I have been trying to use Prisma ORM v7 with NestJS but have encountered some issues:

Prisma ORM now ships as an ES module and requires the following changes:

Addition of "type": "module" in package.json:

{
  "type": "module",
  "scripts": {...},
}

Without this, the following error is observed when attempting to install and use Prisma with Nestjs as per the NestJS docs:
ReferenceError: exports is not defined in ES module scope

However, adding that configuration requires all imports to explicitly end with .js or .ts, which is not the default in Nestjs.

The Upgrade to Prisma ORM 7 also requires these configurations in tsconfig.json:

{
  "compilerOptions": {
    "module": "ESNext",
    "moduleResolution": "node",
    "target": "ES2023",
    "strict": true,
    "esModuleInterop": true
  }
}

However, adding these configurations gives the following error:
Option 'resolvePackageJsonExports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.ts

Disabling resolvePackageJsonExports gives:
Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/path/dist/src/app.module' imported from /path/dist/src/main.js

I am unsure how to proceed, any oversights or identifications of knowledge gaps would be much appreciated, thank you!

[micalevisk]

This is about how to use ESM in a CJS app, right? Not directly related with nestjs

[RareParsec]

This is about how to use ESM in a CJS app, right? Not directly related with nestjs

Yes that's accurate.

The reason I bring this up is because a couple days ago NestJS's guide for Prisma was updated for Prisma v7 #3349. However, the docs make no mention of this ESM and CJS mismatch.

Anyone starting out with Nestjs and following the docs will encounter the same issues I encountered in this Github Issue. Yet, anyone not using Prisma v7 yet may also face issues because they will be following docs specifically for Prisma v7 but using them for a different version.

I think this issue should be acknowledged in the docs.

[micalevisk]

you're correct. Please open a PR to address that, if you're willing for it.

[RareParsec]

Please open a PR to address that

I can give it a try. How should this PR be approached?

I wasn't able to find any solution myself for this ESM+CJS mismatch, but I'm not very well-versed in this so I may have missed something. Do you know of any solution to include in the PR?

If there isn't a solution, I personally think it would be best to revert the Prisma guide to its previous state, and have the current updated v7 guide be put on a separate page. The reverted Prisma guide can then link the updated v7 guide at the top in a notice with a warning about the ESM issue for anyone willing to give it a shot.

Do you think this approach is valid, @micalevisk?

[micalevisk]

yeah, having a dedicated guide for the v7 sounds better to me. Just mention it in the current v6 one (and pin the prisma version in there)

Not sure how would be a better way for the v7 but you can create a PR to fix the current one already

[kamilmysliwiec]

Shouldn't updating the tsconfig file be sufficient in this case?

[RareParsec]

Hi @kamilmysliwiec, you are correct.

I spent some time re-testing just now, and it does now seem to be working with the tsconfig updates

"module": "ESNext",
"moduleResolution": "node",

NestJS by default installs with a resolvePackageJsonExports option enabled which doesn't work when moduleResolution is set to ESNext as shown by this error:

Option 'resolvePackageJsonExports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.ts

Yesterday, when I disabled the resolvePackageJsonExports option during testing, it gave me an error which made me think NestJS needed that resolvePackageJsonExports to work:

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/path/dist/src/app.module' imported from /path/dist/src/main.js

This error doesn't show up today. I'm not sure what caused the error the error yesterday, maybe I didn't re-compile the app properly or something.

Apologies for the confusion.

I will close the PR to revert the Prisma docs.

Since users upgrading to Prisma v7 will likely hit this exact resolvePackageJsonExports error, would you be open to a PR that adds the required tsconfig settings to the Prisma guide?

EDIT:
see below comment

[RareParsec]

The issue is back. I keep getting:
Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/path/dist/src/app.module' imported from /path/dist/src/main.js

I have made a minimal-reproduction repo, I've followed the initialization steps listed in the NestJS Prisma guide and followed the package.json and tsconfig configurations at Prisma's official guide. Attempting to do npm run start:dev produces the error listed at the start of this comment. Please take a look incase I've done something wrong:

https://github.com/RareParsec/Prisma-V7-NestJS-Test.git

[Amitava7]

Dont change your whole project from cjs to ESM just to support prisma. it's easier to just ask prisma to o generate cjs client.

add moduleFormat= "cjs" in the prisma generator instead, that works fine

[RareParsec]

@Amitava7 you're amazing. I thought Prisma v7 completely removed cjs support but moduleFormat= "cjs" does the trick.

generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
  moduleFormat  = "cjs"
}

This needs to be in the documentation, I'll make a pr when I get home for this

[SawkaDev]

@RareParsec can you clarify your settings for the tsconfig + package.json, and if you could provide a sample import of a generated prisma type or the prisma client into one of your application files?

[RareParsec]

@SawkaDev With the moduleFormat= "cjs" approach you don't need to touch or do anything with the tsconfig or package.json files. Simply adding the moduleFormat option in the generator is enough:

generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
  moduleFormat  = "cjs"
}

Prisma v7 now requires you to define a custom output path. You will be importing generated prisma types and the client from the output path that you specify in the generator. In the above example the specified path is ../src/generated/prisma, thus all my imports will be from there.

I've also just updated the repo with the working solution https://github.com/RareParsec/Prisma-V7-NestJS-Test.git. You can take a look there for a working example.

In the repo the app.service.ts has the importing examples