DataProxy Client only works if I instantiate a normal Client first

[janpio]

This is a suuuuper weird problem that I encountered when doing not very common things, so it is probably an edge case, but still super interesting.

Here is the reproduction: https://github.com/janpio/prisma-3.12.0_simple/tree/weird
Get the .env content from this internal conversation in #prisma-data-proxy: https://prisma-company.slack.com/archives/C02C34KRHBQ/p1649182410797739
When you npm install and then npx ts-node scripts.ts this should happen:

C:\Users\Jan\Documents\throwaway\3.12.0_simple>npx ts-node scripts.ts
C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\dataproxy\runtime\proxy.js:96
It should have this form: { url: "CONNECTION_STRING" }`);if(typeof a!="string")throw new Re(`Invalid value ${JSON.stringify(a)} for datasource "${r}" provided to PrismaClient constructor.
                                                                                     ^
PrismaClientConstructorValidationError: Invalid value undefined for datasource "db" provided to PrismaClient constructor.
It should have this form: { url: "CONNECTION_STRING" }
Read more at https://pris.ly/d/client-constructor
    at Object.datasources (C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\dataproxy\runtime\proxy.js:96:86)
    at validatePrismaClientOptions (C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\dataproxy\runtime\proxy.js:97:1841)
    at new PrismaClient (C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\dataproxy\runtime\proxy.js:104:541)
    at Object.<anonymous> (C:\Users\Jan\Documents\throwaway\3.12.0_simple\scripts.ts:7:25)
    at Module._compile (node:internal/modules/cjs/loader:1103:14)
    at Module.m._compile (C:\Users\Jan\Documents\throwaway\3.12.0_simple\node_modules\ts-node\src\index.ts:1455:23)
    at Module._extensions..js (node:internal/modules/cjs/loader:1155:10)
    at Object.require.extensions.<computed> [as .ts] (C:\Users\Jan\Documents\throwaway\3.12.0_simple\node_modules\ts-node\src\index.ts:1458:12)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)

This error message already looks invalid, as the code looks exactly like that.

Now uncomment lines 4 to 6, and this changes:

C:\Users\Jan\Documents\throwaway\3.12.0_simple>npx ts-node scripts.ts
  prisma:tryLoadEnv Environment variables loaded from C:\Users\Jan\Documents\throwaway\3.12.0_simple\.env +0ms
  prisma:tryLoadEnv Environment variables loaded from C:\Users\Jan\Documents\throwaway\3.12.0_simple\.env +3ms
  prisma:client dirname C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\library +0ms
  prisma:client relativePath .. +0ms
  prisma:client cwd C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma +1ms
  prisma:client clientVersion: 3.12.0 +2ms
  prisma:client clientEngineType: library +0ms
  prisma:client:libraryEngine internalSetup +0ms
prisma:query query {
  findManyFoo {
    id
    name
  }
}
  prisma:client:libraryEngine Searching for Query Engine Library in C:\Users\Jan\Documents\throwaway\3.12.0_simple\.prisma\client +71ms
  prisma:client:libraryEngine Searching for Query Engine Library in C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\library +1ms
  prisma:client:libraryEngine loadEngine using C:\Users\Jan\Documents\throwaway\3.12.0_simple\prisma\library\query_engine-windows.dll.node +1ms
prisma:info Calling https://aws-us-east-1.prisma-data.com/3.12.0/11e52bd7ecad95f9f3809fd9d8fec1533840f048c3c245ce8b703d8ff19d2fb3/graphql (n=0)
foo proxy [ { id: '624c5afcef6abe4179942612', name: 'foo' } ]
  prisma:client:libraryEngine hookProcess received: beforeExit +2s
  prisma:client:libraryEngine runBeforeExit +1ms
  prisma:client:libraryEngine hookProcess received: exit +1ms

(Using 3.12.0)

[janpio]

Turns out, the data proxy Client is not loading the .env file and hence the env var is not defined. Setting it manually before executing the script makes it run as it should. Seems the new PrismaClient() for DataProxy is missing some logic.