Install

npm i @shakajs/nestjs-config --save

Using

1. Create config file:

import { ConfigDefaultValue } from '@shakajs/nestjs-config';

export class AppConfig {
  @ConfigDefaultValue(() => process.env.DB_HOST || 'localhost')
  dbHost: string;

  @ConfigDefaultValue(() => process.env.DB_PORT || '3306')
  dbPort: string;

  @ConfigDefaultValue(() => process.env.DB_USER || 'root')
  dbUser: string;
  
  @ConfigDefaultValue(() => process.env.DB_PASSWORD || '')
  dbPassword: string;
  
  @ConfigDefaultValue(() => process.env.TOKEN || '')
  token: string;
}

Note: if you have .env it values will be loaded automatically.

2. Register created config in root-module:

import { Module } from '@nestjs/common';
import { ConfigModule } from '@shakajs/nestjs-config';
import { AppConfig } from './app.config';

@Module({
  imports: [
    ConfigModule.register({ schemas: [AppConfig] }),
  ],
})
export class AppModule {}

3. Use in service:

import { Injectable } from '@nestjs/common';
import { AppConfig } from '../app.config';
import { InjectConfig } from '@shakajs/nestjs-config';

@Injectable()
export class ExampleService {
  constructor(
    @InjectConfig() private readonly config: AppConfig,
  ) {
  }
  
  getTokenFromCongig() {
    return this.config.token;
  }
}

4. Use in custom provider:

import { APP_CONFIG } from '@shakajs/nestjs-config';

...

providers: [  
  {
    provide: 'SOME_VALUE',
    useFactory: (config: AppConfig) => {
      return config.someKey;
    },
    inject: [APP_CONFIG],
  }
],