Package Exports

@nestjs-library/config
@nestjs-library/config/dist/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@nestjs-library/config) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

@nestjs-library/config

A NestJS module for managing environment variables easily and securely.

Features

Decentralizes environment variables by managing each as a provider
Protects changing values of environment variable by developer's mistake
Supports strong validation
Supports type inference
Supports modifying environment variables at runtime via remote config(such as Apache ZooKeeper etc).

Installation

# npm
npm install @nestjs-library/config

# yarn
yarn add @nestjs-library/config

# pnpm
pnpm add @nestjs-library/config

Usage

Step 1. Create a Config service

In @nestjs-library/config, each environment variable is managed by a provider. So, you should create a config service first.

We use class-transformer internally for transforming environment variables to Config Class. You can use decorators such as @Expose and @Type as your need.

// database-config.service.ts
import { Injectable } from '@nestjs/common';
import { AbstractConfigService } from '@nestjs-library/config';
import { Expose, Type } from 'class-transformer';

@Injectable()
export class DatabaseConfigService extends AbstractConfigService<DatabaseConfigService> {
    @Expose({ name: 'DATABASE_HOST' })
    host: string;

    @Expose({ name: 'DATABASE_PORT' })
    @Type(() => Number)
    port: number;

    @Expose({ name: 'DATABASE_PASSWORD' })
    password: string;
}

Step 2. Add decorator for validation and default value

You can use decorators from class-validator for validation and @Transform() decorator of class-transformer for providing default value.

// database-config.service.ts
import { Injectable } from '@nestjs/common';
import { AbstractConfigService } from '@nestjs-library/config';
import { Expose, Transform, Type } from 'class-transformer';
import { IsNotEmpty, IsPositive, IsString } from 'class-validator';

@Injectable()
export class DatabaseConfigService extends AbstractConfigService<DatabaseConfigService> {
    @Expose({ name: 'DATABASE_HOST' })
    @Transform(({ value }) => value ?? 'localhost')
    @IsString()
    @IsNotEmpty()
    host: string;

    @Expose({ name: 'DATABASE_PORT' })
    @Type(() => Number)
    @Transform(({ value }) => value ?? 5532)
    @IsPositive()
    port: number;

    @Expose({ name: 'DATABASE_PASSWORD' })
    @Transform(({ value }) => value ?? 'local')
    @IsString()
    @IsNotEmpty()
    password: string;
}

Step 3. Import Config module into your module

// test.module.ts
import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs-library/config';

import { DatabaseConfigService } from './database-config.service';
import { TestService } from './test.service';

@Module({
    imports: [ConfigModule.forFeature(DatabaseConfigService)],
    providers: [TestService],
    exports: [TestService,]
})
export class TestModule {}

Step 4. Inject Config service where you need

// test.service.ts
import { Injectable } from '@nestjs/common';
import { DatabaseConfigService } from './database-config.service';

@Injectable()
export class TestService {
    constructor(private readonly databaseConfigService: DatabaseConfigService) {}

    getDatabaseConfig() {
        return this.databaseConfigService;
    }
}

Contributing

(To be added)

License

This library is licensed under the MIT License. See the LICENSE file for details.