Make Prisma generate independent of environment

[divyenduz]

prisma generate fails when a particular environment variable is not available. The reason(s) for this are:

datasource ds {
  provider = env("DB_PROVIDER")
  url = env("DB_URL")
}

If DB_PROVIDER is used, then the generate CLI needs to resolve it to proceed as it needs to know the data source. A potential solution is to dis-allow environment variables in provider. This issue: prisma/prisma-client-js#184 also ties into this discussion.

Decision: Disallow env vars in provider

If DB_URL is used, then for SQLite, we need to be able to resolve the relative path to the SQLite file at generate time, to be able to use it at runtime. A potential solution is to limit SQLite to absolute paths but that is not the best DX.

Decision: Do not resolve SQLite path when generation

Had a quick chat with @schickling and the result is above marked decisions.

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Another alternative is to fail only on the required env vars (like provider) but let others pass through. That would require the datamodel parser to bake the field information in the parse tree and that can be used to fail conditionally.

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This information is from top of my head and might be outdated, I will sync with @timsuchanek on this.

[divyenduz]

Internal note: This happens without schema parser, i.e. no VSCode support

VSCode support tracked here prisma/language-tools#17

[matthewmueller]

Matt: Update spec to include "Disallow env vars in provider"

[mavilein]

Env vars are now disallowed in the provider argument of datasources (PR). This will be available in alpha shortly.

[marcjulian]

Updating from prisma 2.0.0-beta.2 to 2.0.0-beta.3 I am now receiving the following error

npx prisma generate
Error: Schema parsing
error: Error validating source `db`: You must provide a nonempty URL for the datasource `db`. The environment variable `POSTGRESQL_URL` resolved to an empty string.
  -->  schema.prisma:3
   | 
 2 |   provider = "postgresql"
 3 |   url      = env("POSTGRESQL_URL")
   |

I am setting an empty string for POSTGRESQL_URL for npm install. This error occurs on GitHub actions and the error is available here

[pantharshit00]

@marcjulian Can you please open a new issue about this?

[marcjulian]

Added the issue 2321