Doesn't work with the Prisma fluent API

[hightail191]

Describe the Bug
I have trouble in using prisma-field-encryption middleware when using prisma fluent API. Not decrypted data are returned when I request data through prisma fluent API. To avoid N+1 problem, I want to use fluent API which can use prisma data loader.

To Reproduce
Add prisma-field-encryption middleware. Make schema which has parent-children relation model and @Encrypted field in children model. (see my code below)

Expected Behavior
I expect data which are requested through prisma fluent API to be decrypted.

Environment:

OS: ubuntu 22.04.1
Node 20.2.0
Prisma version 5.2.0
prisma-field-encryption 1.5.0
TypeScript version 5.2.2
Express 4.18.2

Additional Context

This is my github repository

Prisma schema

// schema.prisma
// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = "postgresql://postgres:postgres@db:5432/adgame?schema=public"
}

model User {
  id    Int     @id @default(autoincrement())
  email String
  name  String? /// @encrypted
  posts Post[]
}

model Post {
  id        Int     @id @default(autoincrement())
  title     String
  content   String? /// @encrypted
  published Boolean @default(false)
  author    User    @relation(fields: [authorId], references: [id])
  authorId  Int
}

Express Server

// server.ts

import express from "express";
import { PrismaClient } from "@prisma/client";
import { fieldEncryptionExtension } from "prisma-field-encryption";

const globalClient = new PrismaClient();

const client = globalClient.$extends(
  fieldEncryptionExtension({
    encryptionKey: "k1.aesgcm256.DbQoar8ZLuUsOHZNyrnjlskInHDYlzF3q6y1KGM7DUM=",
  })
);

const app = express();

const server = app.listen(3000, function () {
  console.log("start server");
});

// data are decrypted when using normal query
app.get("/userposts1", async (req, res, next) => {
  const user = await client.user.findFirst();
  const authorId = user?.id || 1;
  const posts = await client.post.findMany({
    where: {
      authorId: authorId,
    },
  });
  console.log(posts);
  res.send(posts);
});

// data are not decrypted when using fluent API
app.get("/userposts2", async (req, res, next) => {
  const posts = await client.user.findFirst().posts();
  console.log(posts);
  res.send(posts);
});

[franky47]

Thanks for the reproduction repo, I'll have a look.

In the mean time, what do the debug logs say when you hit the fluent endpoint?

DEBUG="prisma-field-encryption:*" node your-server.js

[hightail191]

Thank you for your reply.
This is my debug logs when I hit fluent endpoint.

debug logs

2023-08-30T17:24:19.777Z prisma-field-encryption:encryption Clear-text input: {
args: { select: { posts: true } },
model: 'User',
action: 'findFirst',
dataPath: [],
runInTransaction: false
}
2023-08-30T17:24:19.779Z prisma-field-encryption:encryption Encrypted input: {
args: { select: { posts: true } },
model: 'User',
action: 'findFirst',
dataPath: [],
runInTransaction: false
}
2023-08-30T17:24:19.785Z prisma-field-encryption:decryption Raw result from database: [
{
id: 5,
title: 'Post1',
content: 'v1.aesgcm256.2fc1baee.BYsfYrU7k6ppBv0t.n_MIe9lb-jpIveEs3jfRVH2LJGxU4pvvvqECrFg=',
published: false,
authorId: 5
},
{
id: 6,
title: 'Post2',
content: 'v1.aesgcm256.2fc1baee.srH0TPxsXRm2DDz2.2U9FRykgqty9jiIlGQTLFlnA_EWRysmhUW41oSs=',
published: false,
authorId: 5
}
]
2023-08-30T17:24:19.787Z prisma-field-encryption:decryption Decrypted result: [
{
id: 5,
title: 'Post1',
content: 'v1.aesgcm256.2fc1baee.BYsfYrU7k6ppBv0t.n_MIe9lb-jpIveEs3jfRVH2LJGxU4pvvvqECrFg=',
published: false,
authorId: 5
},
{
id: 6,
title: 'Post2',
content: 'v1.aesgcm256.2fc1baee.srH0TPxsXRm2DDz2.2U9FRykgqty9jiIlGQTLFlnA_EWRysmhUW41oSs=',
published: false,
authorId: 5
}
]

[franky47]

Thanks, I think I have an idea of what is going on.

The query coming into the extension asks for a user, with included posts:

{
  args: { select: { posts: true } },
  model: 'User',
  action: 'findFirst',
  dataPath: [],
  runInTransaction: false
}

However, the data coming back from the database (or rather from the client engine doing its thing) is a list of Posts:

[
  {
    id: 5,
    title: 'Post1',
    content: 'v1.aesgcm256.2fc1baee.BYsfYrU7k6ppBv0t.n_MIe9lb-jpIveEs3jfRVH2LJGxU4pvvvqECrFg=',
    published: false,
    authorId: 5
  },
  {
    id: 6,
    title: 'Post2',
    content: 'v1.aesgcm256.2fc1baee.srH0TPxsXRm2DDz2.2U9FRykgqty9jiIlGQTLFlnA_EWRysmhUW41oSs=',
    published: false,
    authorId: 5
  }
]

This throws the decryption engine off which was expecting a User model, with some connections to a list of Posts, not the posts themselves.

Since Prisma does this downstream and doesn't give us any info of this change (neither from the input arguments nor from the returned data), I don't see how we can handle this and differenciate it from a regular (non-Fluent) call.

[franky47]

FYI, I have opened a discussion about this behaviour on the Prisma repo: prisma/prisma#20901

[hightail191]

Thank you very much. I don't have any idea about solving this problem because there is no information on the Internet.
OK. I 'll follow the discussion.