result extension that shadows a field of the same name causes Maximum call stack exceeded at runtime

[sbking]

Bug description

When a result extension adds a computed field that shadows a field of the same name, AND the extension field needs the shadowed field, the following error occurs:

RangeError: Maximum call stack size exceeded
    at Array.flatMap (<anonymous>)
    at /Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31121:48
    at Cache.getOrCreate (/Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31090:19)
    at resolveNeeds (/Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31119:18)
    at Array.flatMap (<anonymous>)
    at /Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31121:48
    at Cache.getOrCreate (/Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31090:19)
    at resolveNeeds (/Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31119:18)
    at Array.flatMap (<anonymous>)
    at /Users/stephen/Projects/prisma-client-extensions-shadowing/node_modules/@prisma/client/runtime/index.js:31121:48 {
  clientVersion: '4.7.1'
}

Here is where the issue actually happens:

https://github.com/prisma/prisma/blob/main/packages/client/src/runtime/core/extensions/resultUtils.ts#L58

(resolveNeeds doesn't check for cycles in the dependencies)

How to reproduce

Repository with a minimal reproduction and instructions in the README: https://github.com/sbking/prisma-client-extensions-shadowing

Expected behavior

A computed field should be able to shadow a field of the same name, and use the original value to compute the computed value.

This works at the type level - the extended client uses the data type returned by the computed field, not the type of the original field.

The TypeScript types also seem suggest that you can chain extensions that shadow the same computed field. This would be intuitive, but the docs suggest that the last extension always wins in the case of conflicts. See the inferred inlay hints in this screenshot:

Prisma information

generator client {
  provider        = "prisma-client-js"
  previewFeatures = ["clientExtensions"]
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

model Post {
  id        String   @id @default(cuid())
  title     String
  createdAt DateTime @default(now())
}

Here is the extension code:

const prisma = new PrismaClient().$extends({
  name: "i18n",
  result: {
    post: {
      createdAt: {
        needs: { createdAt: true },
        compute(post) {
          return formatDistanceToNow(post.createdAt, { locale: de });
        },
      },
    },
  },
});

async function main() {
  const posts = await prisma.post.findMany({
    select: {
      title: true,
      createdAt: true,
    },
    take: 5,
  });

  for (const post of posts) {
    console.info(`- ${post.title} (${post.createdAt})`);
  }
}

And here is where the error occurs:

async function main() {
  const posts = await prisma.post.findMany({
    select: {
      title: true,
      createdAt: true,
    },
    take: 5,
  });

  for (const post of posts) {
    console.info(`- ${post.title} (${post.createdAt})`);
  }
}

Environment & setup

• OS: macOS
• Database: PostgreSQL
• Node.js version: v18.10.0

Prisma Version

4.7.1