Environment variables provider for Nest.JS project.

This library enables you to get a collection of environment variable as a class and validate model using by a class validation way.

Required TypeScript Configuration

For your NestJS project to work with this package, ensure your tsconfig.json has at least these compiler options:

{
  "compilerOptions": {
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "outDir": "./dist",
    "target": "ES2023"
  }
}
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These settings are required because:

• emitDecoratorMetadata and experimentalDecorators: Required for NestJS decorators and class validation
• module and moduleResolution: Set to "NodeNext" for compatibility with modern Node.js
• target: ES2023 or later for modern JavaScript features
• outDir: Defines the output directory for compiled JavaScript files, keeping the build artifacts (usually in dist/) separate from the source TypeScript files.

Usage

Let's consider this .env file in your project.

DATABASE_URL=test
ADMIN_EMAIL=a.a@a.com
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Define a class model to store your environment variables :

import { EmailProperty, StringProperty } from '@otakusan76/nestjs-environment-variables-provider/decorators';

export class EnvironmentVariables {
    @StringProperty()
    public readonly DATABASE_URL!: string;

    @EmailProperty()
    public readonly ADMIN_EMAIL!: string;
}
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Define your module and register the "EnvironmentConfigModule" module :

import { Module } from '@nestjs/common';
import { EnvironmentConfigModule } from '@otakusan76/nestjs-environment-variables-provider';
import { EnvironmentVariables } from './environment-variables.ts

@Module({
    imports: [EnvironmentConfigModule.forRoot(EnvironmentVariables)],
})
export class AppModule {}
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Call the environment variable provider in your custom code:

import { Inject, Injectable } from '@nestjs/common';
import { EnvironmentVariablesProvider } from '@otakusan76/nestjs-environment-variables-provider';
import { EnvironmentVariables } from './environement-variables.js';

@Injectable()
export class CustomService {
  constructor(@Inject() private readonly provider: EnvironmentVariablesProvider) {}

  public doSomething(): void {
    const environementVariables: EnvironmentVariables = this.provider.getEnvironmentVariables(EnvironmentVariables);
    console.log('Environment Variables:', environementVariables);
  }
}
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Documentation

• @otakusan76/nestjs-environment-variables-provider Documentation

License

The MIT License.

Author

Maxime Aubry