Environment Variable Substitution Not Working

[Nathan-Bernardo]

I'm submitting a...

• [ ] Regression
• [ ] Bug report
• [ ] Feature request
• [ ] Documentation issue or request
• [x] Support request

Current behavior

Environment variable substitution defined in .env doesn't seem to be substituted into .env.yaml even when ignoreEnvironmentVariableSubstitution: false for file loader. Config file is defined below

// .env
PORT=9000
LOADER=fileLoader

app:
  somePort: ${PORT:-12345}
  envLoader: ${LOADER}

The current output is

app: 
    somePort: 12345
    envLoader: undefined

Expected behavior

Expected output

app:
    somePort: 9000
    envLoader: fileLoader

Minimal reproduction of the problem with instructions

https://gist.github.com/Nathan-Bernardo/bcb98b2215571223299209b9088489f2

Environment

Nest version: 8.0.0
Nest-Typed-Config version: 2.9.1


For Tooling issues:
- Node version: 16.18.2  
- Platform: Ubuntu 18.04            

[Nikaple]

Tried your code with latest version, and it's working fine for me:

env variable substitution for fileLoader was implemented in v2.9.0, please reinstall the dependencies and try again.

[mydnicq]

I have the same problem. My yml is:

app:
  port: 3006
db:
  dbHost: ${DB_HOST:'localhost'}

And my ConfigModule looks like:

export const ConfigModule = TypedConfigModule.forRoot({
  schema: Config,
  load: fileLoader({ disallowUndefinedEnvironmentVariables: true }),
});

I was expecting at least throwing an error, because DB_HOST is not set or value should default to localhost. But got this returned:

Config {
app: AppConfig { port: 3006 },
db: DbConfig {
    dbHost: "${DB_HOST:'localhost'}",
}

Using the latest version 2.9.2.

[Nikaple]

@taRusty see the test files for substitution reference, it's the same with dotenv-expand and not relevant with this issue. CodeSandbox link: https://codesandbox.io/p/devbox/brave-chatelet-jfd7zl?file=%2Fsrc%2Fconfig.ts%3A25%2C1

[mydnicq]

Oh, I had the wrong configuration then. It should be "${DB_HOST:-localhost}" instead"${DB_HOST:'localhost'}". And then, I was also missing ignoreEnvironmentVariableSubstitution: false. Didn't know the default is true. My bad and apologies for this. Thank you for your help.