Validation is not performed on config loaded with custom loader

[sergey-shablenko]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

we load and validate config outside of nestjs and just provide already parsed config to the module like this

    ConfigModule.forRoot({
      isGlobal: true,
      ignoreEnvFile: true,
      ignoreEnvVars: true,
      expandVariables: false,
      // no validation needed, it is validated during load
      validate: (config) => config,
      load: [get],
    })

when we try to use config service

configService: ConfigService<EnvironmentVariables, true>

typings are correct, it recognises numbers, booleans, e.t.c, but returns raw string value from _cache causing broken types

Minimum reproduction code

aint nobody got time for that (sorry)

Steps to reproduce

No response

Expected behavior

validate logic should be called on objects loaded from custom loaders to have consistent logic and safe types

Package version

3.1.1

NestJS version

10.2.6

Node.js version

18.16.0

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

Sorry that I did not provide reproduction code, but it is easy to track down without it. Either trust loaded config and add it to validated cache, or run validation logic to add it there

[sergey-shablenko]

or maybe change order of operations, to fallback to internal config before process.env

[Robert Tabacaru]

I bumped into this as well and would benefit from the behaviour being changed :D

EDIT: As a workaround, I just manually validated each slice before returning it from registerAs and ended up not having it on the main configuration object.