🚀 nestjs-auto-env-joi

Auto Joi validation schema generation for .env files in NestJS projects.
👉 Save time by auto-generating your validation schema from comments in your .env file!

✨ Features

• ✅ Supports basic types: string, number, boolean, email, date.
• ✅ Supports enum with allowed values → // enum:admin|user|guest.
• ✅ Supports optional variables → // optional.
• ✅ Automatically marks variables as required by default.
• ✅ Works seamlessly with @nestjs/config's validationSchema.
• 🛑 If you forget to add a type tag, the server will throw an error at startup and tell you exactly which line to fix!

📦 Installation

npm install nestjs-auto-env-joi
# or
yarn add nestjs-auto-env-joi

🛠️ Usage Example in NestJS

Create a .env file in your project root with type annotations as comments:

// string
DATABASE_URL=postgres://example

// optional
PORT=3000

// enum:admin|user|guest
USER_ROLE=admin

// boolean
DEBUG=true

Then import and use AutoEnvValidation in your AppModule:

import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';
import { AutoEnvValidation } from 'nestjs-auto-env-joi';

@Module({
  imports: [
    ConfigModule.forRoot({
      validationSchema: AutoEnvValidation({
        envPath: '.env', // Optional, defaults to '.env'
      }),
    }),
  ],
})
export class AppModule {}

🏷️ Supported Type Tags

| 🏷️ Type Tag | 📝 Description | 🧑‍💻 Example Annotation | |-------------|----------------|------------------------------| | string | Validates as a string (required) | // string | | number | Validates as a number (required) | // number | | boolean | Validates as a boolean (required) | // boolean | | email | Validates as a valid email string (required) | // email | | date | Validates as a valid date (required) | // date | | enum | Validates string in allowed values (required) | // enum:admin\|user\|guest | | optional | Validates as optional | // optional |

⚠️ Important Notes

• 🚨 Each environment variable must have a type tag comment line starting with // directly above it.
• 🚨 If you forget a type tag, your NestJS server will not start and will throw an error showing the line number you need to fix.
• enum tags must include allowed pipe-separated values.
• All variables are required by default unless marked with // optional.
• The .env file must exist at the path provided (default .env).

📄 License

MIT

✍️ Author

Yassine Jdidi

❤️ Happy coding with strong env validation!