https://github.com/nestjs-steroids/environment

:gear: Extremely simple environment module
https://github.com/nestjs-steroids/environment

Last synced: 2 months ago
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:gear: Extremely simple environment module

• Host: GitHub
• URL: https://github.com/nestjs-steroids/environment
• Owner: nestjs-steroids
• License: mit
• Created: 2020-08-08T11:16:26.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2020-08-08T13:34:40.000Z (over 4 years ago)
• Last Synced: 2024-11-16T01:46:27.104Z (2 months ago)
• Language: TypeScript
• Size: 110 KB
• Stars: 15
• Watchers: 2
• Forks: 2
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
Environment

Extremely simple environment module (config loader) for your NestJS application


## Installation

```bash

npm install @nestjs-steroids/environment

```

## Usage

First of all, let's define our application environment

### AppEnvironment

```typescript

import { IsEnum, IsNumber, Max, Min } from 'class-validator';

import { Transform } from 'class-transformer';

import { Env } from '@nestjs-steroids/environment';

enum NodeEnv {

  Development = 'development',

  Production = 'production'

}

export class AppEnvironment {

  /**

   * Env decorator mark environment variable that we want to assign

   * (Tip) Without name env Env decorator makes auto UPPER_SNAKE_CASE conversion (e.g. isTest -> IS_TEST)

   */

  @Env('PORT')

  /**

   * Transform is useful for all sorts of transformations or parsing complex values

   * For example: @Transform(value => value.toLowerCase() === 'true')

   */

  @Transform(parseInt)

  /**

   * Also, you could use class-validator operators for validation of the correctness of environment variables

   */

  @IsNumber()

  @Min(0)

  @Max(65535)

  port: number;

  @Env('NODE_ENV')

  @IsEnum(NodeEnv)

  nodeEnvironment: NodeEnv

}

```

### AppModule

Then, register `EnvironmentModule` in your application 

```typescript

import { Module } from '@nestjs/common';

import { EnvironmentModule } from '@nestjs-steroids/environment';

import { AppEnvironment } from './app-environment';

@Module({

  imports: [

    EnvironmentModule.forRoot({

      isGlobal: true,

      loadEnvFile: true,

      useClass: AppEnvironment,

    }),

  ],

})

export class AppModule {}

```

### AppService

Let's use our application environment in services

```typescript

import { Injectable } from '@nestjs/common';

import { AppEnvironment } from './app-environment';

@Injectable()

export class AppService {

  constructor(private readonly appEnvironment: AppEnvironment) {}

  getNodeEnvironment(): string {

    return `Application environment is: ${this.appEnvironment.nodeEnvironment}`;

  }

}

```

## Advanced usage

Sometimes we need access to our environments without creation NestJS application (e.g. ORM config, etc.).

So we can create an `AppEnvironment` using `getEnvironment` factory method and use it like class with static properties.

```typescript

import { getEnvironment } from '@nestjs-steroids/environment';

export const appEnv = getEnvironment(AppEnvironment)

// Usage

appEnv.nodeEnvironment

```

Also, we can reuse this instance in `EnvironmentModule`

```typescript

import { Module } from '@nestjs/common';

import { EnvironmentModule } from '@nestjs-steroids/environment';

import { appEnv, AppEnvironment } from './app-environment';

@Module({

  imports: [

    EnvironmentModule.forRoot({

      isGlobal: true,

      loadEnvFile: true,

      useClass: AppEnvironment, // Class that we want to provide

      useValue: appEnv, // Class than we want to provide

    }),

  ],

})

export class AppModule {}

```

## License

[MIT](LICENSE.md)