Is there any way to use #next/env in codegen.yaml? - next.js

Question

I was wondering if there was a way to use #next/env to replace variables in codegen.yaml when i run yarn codegen:
graphql-codegen -r dotenv/config --config codegen.yml - this is codegen example to load dot env
graphql-codegen -r #next/env --config codegen.yml - this is what i want to achieve
When i call it, i get
${SERVER_API_URL}/graphql goes as undefined/graphql
My usecase is:
# .env
HOST=https
API_DOMAIN=example.com
SERVER_API_URL=$HOST://$API_DOMAIN
# codegen.yaml
schema: ${SERVER_API_URL}/graphql
Why use #next/env? it replaces variables in .env, i'm attaching documentation sample from next.js documentation:
Note: Next.js will automatically expand variables ($VAR) inside of
your .env* files. This allows you to reference other secrets, like so:
# .env
HOSTNAME=localhost
PORT=8080
HOST=http://$HOSTNAME:$PORT
If you are trying to use a variable with a $ in the actual value, it needs to be escaped like so: \$.
For example:
# .env
A=abc
# becomes "preabc"
WRONG=pre$A
# becomes "pre$A"
CORRECT=pre\$A
source: https://nextjs.org/docs/basic-features/environment-variables#loading-environment-variables

Answer 1

You can't use #next/env directly via -r flag. However you still have couple of alternatives. For example, you can address the required .env file directly:
DOTENV_CONFIG_PATH=./.env.local graphql-codegen --config codegen.yml -r dotenv/config
If you still want to use #next/env, you can convert your codegen.yml to codegen.js and import #next/env. For example, my original YML:
overwrite: true
schema:
- https://graphql.fauna.com/graphql:
headers:
Authorization: 'Bearer ${FAUNA_ADMIN_KEY}'
documents: null
generates:
src/generated/graphql.ts:
plugins:
- typescript
- typescript-operations
- typescript-graphql-request
./graphql.schema.json:
plugins:
- 'introspection'
I re-wrote it as JS:
const { loadEnvConfig } = require('#next/env')
loadEnvConfig(process.cwd())
module.exports = {
overwrite: true,
schema: {
'https://graphql.fauna.com/graphql': {
headers: {
Authorization: `Bearer ${process.env.FAUNA_ADMIN_KEY}`,
},
},
},
documents: null,
generates: {
'src/generated/graphql.ts': {
plugins: [
'typescript',
'typescript-operations',
'typescript-graphql-request',
],
},
'./graphql.schema.json': { plugins: ['introspection'] },
},
}
and then generated the code using graphql-codegen --config codegen.js.
Here is an issue on Github that helped me.