PNPM install not running prisma generate

Bug description

When installing within a PNPM monorepo the generator isn’t being run. I suspect it might have something to do with PNPM symlinking dependencies and therefore messing with the client postinstall script. Just a guess though.

How to reproduce

Reproduction: https://github.com/scriptcoded/prisma-issue-6603

1. Make sure PNPM is installed. (https://pnpm.io/installation)
2. Clone the reproduction repo: git clone [e-mail]:scriptcoded/prisma-issue-6603.git
3. Enter the app directory: cd prisma-issue-6603/app
4. Install dependencies using PNPM: pnpm i
5. Run the application: pnpx ts-node index.ts
6. Observe that the Prisma client has not been generated

Expected behavior

The Prisma client should be generated and the application should run without issues.

Prisma information

Project set up accoring to the Start from scratch guide.

Environment & setup

• OS: Manjaro Linux x86_64
• Database: PostgreSQL 12
• Node.js version: v14.15.2
• Prisma version:

prisma               : 2.21.2
@prisma/client       : 2.21.2
Current platform     : debian-openssl-1.1.x
Query Engine         : query-engine e421996c87d5f3c8f7eeadd502d4ad402c89464d (at ../node_modules/.pnpm/@prisma+engines@2.21.0-36.e421996c87d5f3c8f7eeadd502d4ad402c89464d/node_modules/@prisma/engines/query-engine-debian-openssl-1.1.x)
Migration Engine     : migration-engine-cli e421996c87d5f3c8f7eeadd502d4ad402c89464d (at ../node_modules/.pnpm/@prisma+engines@2.21.0-36.e421996c87d5f3c8f7eeadd502d4ad402c89464d/node_modules/@prisma/engines/migration-engine-debian-openssl-1.1.x)
Introspection Engine : introspection-core e421996c87d5f3c8f7eeadd502d4ad402c89464d (at ../node_modules/.pnpm/@prisma+engines@2.21.0-36.e421996c87d5f3c8f7eeadd502d4ad402c89464d/node_modules/@prisma/engines/introspection-engine-debian-openssl-1.1.x)
Format Binary        : prisma-fmt e421996c87d5f3c8f7eeadd502d4ad402c89464d (at ../node_modules/.pnpm/@prisma+engines@2.21.0-36.e421996c87d5f3c8f7eeadd502d4ad402c89464d/node_modules/@prisma/engines/prisma-fmt-debian-openssl-1.1.x)
Default Engines Hash : e421996c87d5f3c8f7eeadd502d4ad402c89464d
Studio               : 0.371.0

[millsp]

Hey @jlarmstrongiv this has not been released as it would cause many side-effects and breaking changes. Issues with automatic pnpm generation have not been fixed. However, if you just want to have multiple generated clients in your monorepo, you can have per-package generation folders (in their node_modules folder) instead of the root one. You can simply add this to your schema:

generator client {
  provider = "prisma-client-js"
  output = "../node_modules/.prisma/client" // <-- generate in your package node_modules, not the root
}

import { PrismaClient } from '.prisma/client' // <-- import the dot generated folder, not @prisma/client

[millsp]

@scriptcoded thanks for your bug report!

At the moment, it gets generated in your workspace’s node_modules and not in the package’s node_modules (if you run pnpx prisma generate). This would be fine for only one package but not many.

Now, there’s another problem, you want to import @prisma/client. That’s not possible because of pnpm and the way we resolve the generated .prisma/client. In short, when you install, pnpm will put @prisma/client in your workspace’s node_modules. This has three effects:

1. We can’t resolve the .prisma/client via @prisma/client because they don’t live in the same node_modules folder. The one is in the workspace, and the other is in the package.
2. When you import @prisma/client it then tries to import the neighbor .prisma/client. For the reason explained above, this is not possible. Even though pnpm claims to hardlink, this does not happen on the folders (not possible).
3. For the same reasons, we would not be able to provide the right types for each package (assuming that you have multiple packages using multiple clients, each with a different schema).
4. That’s how things are resolved by import / require.

For the reasons above, I suggest that on such a pnpm monorepo setup, you would not import @prisma/client, but you would import the generated .prisma/client directly instead. It would be wise that we document this.

If you would like to give it a try, please use prisma@2.24.0-integration-fix-paths.3 and @prisma/client@2.24.0-integration-fix-paths.3. It still won’t generate automatically on install, but at least you can do pnpx prisma generate in your package’s folder. Not closing the issue until that works automatically on install. Your feedback is very welcome 😃