prisma: `TypeError: at normalizeAndValidateHeaderValue` with data proxy in cloudflare workers/miniflare

Bug description

Client is bugged in my closed source project but also in this open source project I found it so using that as an example.

When using Prisma Data Proxy in Cloudflare Workers with prisma 3.10.0 and miniflare 2.3.0 (also using remix 1.2.3 but probably not related) an error occurs when making any request since the transactionId header is passed as undefined in prisma causing a header normalization error (since undefined isn’t a valid header).

Workaround

I’ve managed to fix the error locally by modifying line 93 col 13582 of node_modules/@prisma/client/runtime/proxy.js to be const headers={...n};if(typeof t=="string"&&r){headers.transactionId= t}return{inTx:typeof t=="number"&&r?!0:void 0,headers} instead of return{inTx:typeof t=="number"&&r?!0:void 0,headers:{transactionId:typeof t=="string"&&r?t:void 0,...n} since in the bugged code the transactionId header will be undefined if not present, thus causing the normalizeAndValidateHeaderValue error.

How to reproduce

1. Go to https://github.com/marcomafessolli/remix-prisma-cloudflare-workers/tree/d86bb949016ce35f805ab113f4df89f3e96b3644 (hard link for current point in time of master branch)
2. Git clone that project
3. Follow the steps to run the project (add an .env, npm i, PRISMA_CLIENT_ENGINE_TYPE=dataproxy npx prisma generate and create your prisma data proxy project if not already using one)
4. Run npm run dev
5. Open the root index page for the website (only one page exists).
6. See error

Expected behavior

TypeError:
[dev:*worker]     at normalizeAndValidateHeaderValue (`<PATH>/remix-prisma-cloudflare-workers/node_modules/undici/lib/fetch/headers.js:42:11`)
[dev:*worker]     at HeadersList.append (`<PATH>/remix-prisma-cloudflare-workers/node_modules/undici/lib/fetch/headers.js:98:29`)
[dev:*worker]     at fill (`<PATH>/remix-prisma-cloudflare-workers/node_modules/undici/lib/fetch/headers.js:86:15`)
[dev:*worker]     at new Request (`<PATH>/remix-prisma-cloudflare-workers/node_modules/undici/lib/fetch/request.js:433:9`)
[dev:*worker]     at new Request (`<PATH>/remix-prisma-cloudflare-workers/node_modules/@miniflare/core/src/standards/http.ts:407:13`)
[dev:*worker]     at upgradingFetch (`<PATH>/remix-prisma-cloudflare-workers/node_modules/@miniflare/web-sockets/src/fetch.ts:20:19`)
[dev:*worker]     at WebSocketPlugin.<anonymous> (`<PATH>/remix-prisma-cloudflare-workers/node_modules/@miniflare/core/src/standards/http.ts:895:21`)
[dev:*worker]     at fetch (`<PATH>/remix-prisma-cloudflare-workers/node_modules/@miniflare/web-sockets/src/plugin.ts:51:28`)
[dev:*worker]     at request (`<PATH>/remix-prisma-cloudflare-workers/node_modules/@prisma/client/runtime/proxy.js:25:12296`)
[dev:*worker]     at Object.requestInternal (`<PATH>/remix-prisma-cloudflare-workers/node_modules/@prisma/client/runtime/proxy.js:27:285`)

Prisma information

generator client {
  provider        = "prisma-client-js"
  previewFeatures = ["mongoDb", "dataProxy"]
}

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

model User {
  id    String  @id @default(auto()) @map("_id") @db.ObjectId
  email String  @unique
  name  String?
}

model Log {
  id      String @id @default(auto()) @map("_id") @db.ObjectId
  level   Level
  message String
  meta    Json
}

enum Level {
  Info
  Warn
  Error
}

Environment & setup

OS: Windows using Fedora 35 via wsl2 Database: PostgreSQL Miniflare: 2.3.0 Prisma: 3.10.0

Prisma Version

3.10.0