Environment variables not available when using Wrangler 2

[drzamich]

Bug description

When using the Data Proxy feature on the Cloudflare Workers runtime I'm getting an error caused by what I think is inability of Prisma edge client to access env variables set by Wrangler.
What's important to note is that I'm using Wrangler 2 (what you get by default if you run npm i wrangler). It's different than what's used in the ecosystem-tests where the legacy Wrangler 1 is used.

Your worker has access to the following bindings:
- Vars:
  - CF_DATA_PROXY_URL: "..."

...

'Uncaught Error: InvalidDatasourceError: Datasource "db" references an environment
  variable "CF_DATA_PROXY_URL" that is not set\n'

How to reproduce

1. git clone git@github.com:prisma/ecosystem-tests.git
2. cd ecosystem-tests/dataproxy/cloudflare-workers
3. npm i
4. npm i -D wrangler
5. npm uninstall @cloudflare/wrangler
6. source ./prepare.sh
7. Remove usage_model = '' line from wrangler.toml
8. npx prisma generate --data-proxy
9. npx wrangler dev src/index.ts

Expected behavior

There's no error.

Prisma information

As in the example.

Environment & setup

• OS: macOS Monterey 12.1
• Database: PostgreSQL
• Node.js version: 16.13.2

Prisma Version

Experienced it in my project on 4.2.1. Reproduced also on 4.3.0-dev.48.

[drzamich]

I did a little investigation on the matter and have some findings

Root cause

Root cause is the different global object between Wrangler 1 (a.k.a @cloudflare/wrangler) and Wranger 2 (a.k.a. wrangler).

When trying to access env vars, Prisma does the following:

packages/client/src/generation/utils/buildInjectableEdgeEnv.ts#74

const cfwEnv = `typeof global !== 'undefined' && global['${envVarName}']`

This works for Wrangler 1. For Wrangler 2 however, global is undefined. I couldn't find any documentation on the matter but it seems that Wrangler 2's runtime is an actual service worker, because the global object referenced with self.

Proposed fix

The fix couldn't be simpler - replacing global with globalThis on the above mentioned line does the job. globalThis is runtime-agnostic and will always return the global object.

Workaround

Turn on the experimental Node compatibiltiy flag in by adding the following to wrangler.toml

node_compat=true

[yamiteru]

Still doesn't work..

ReferenceError: DATABASE_URL is not defined.
Attempted to access binding using global in modules.
You must use the 2nd `env` parameter passed to exported handlers/Durable Object constructors, or `context.env` with Pages Functions.

I generate with prisma generate and run dev with wrangler dev --local.

[janpio]

Please open a new issue with a full description of your problem. Thanks.