@sdu-turing/config

@sdu-turing/config, another way to config Environment Variables in Nest.JS.

Usage

Installation

$ npm i @sdu-turing/config
# used for environment variables schema validation
$ npm i class-validator class-transformer

Examples

First, create config/user.config.ts

// config/user.config.ts
import { Env } from '@sdu-turing/config';
import { IsEnum, IsString, IsUrl } from 'class-validator';

export class UserConfigSchema {
  @IsEnum(NodeEnvironment)
  NODE_ENV: NodeEnvironment;

  @IsString()
  MONGO_URI: string;

  @IsString()
  TURING_APP_ID: string;

  @IsUrl()
  OAUTH_SERVICE_URL: string;

  // ...
}

export class UserConfig {
  mongoUri: string;

  constructor(@Env() env: UserConfigSchema) {
    this.mongoUri = env.MONGO_URI;
  }
}

optional, create .env file, or just use process.env.

# .env
MONGO_URI=mongodb://....
....

register ConfigModule in AppModule:

@Module({
  imports: [
    ConfigModule.forRoot({
      schemas: [UserConfigSchema], // the schemas
      configs: [UserConfig], // register provider as global
    }),
  ],
})
export class AppModule {}

Usage

ConfigModule.forRoot({
  // [optional] load .env file? default: `true`
  loadDotEnv: true,
  // [optional] the schema you want to validate for environment variables
  schemas: [],
  // [optional] the string to throw if an error occurs in validation
  validationErrorMessage: '' | (errors: ValidationError[]) => string,
  // [optional] cache process.env to improve performance, default false
  useCache: false,
  // [optional] these configs are registered as global providers
  // or use ConfigModule.forFeature(configs) in scope,
  configs: []
})

In a provider, a ConfigService or UserConfig, use @Env() to inject the process.env(or cache).

class ConfigService {
  @Env()
  env: EnvironmentVariables;
}