Fastify Auto Env Validator

Fastify Auto Env Validator is a Fastify plugin that automatically detects, validates, and manages required environment variables in your Node.js projects.

A Fastify plugin that automatically detects, validates, and ensures required environment variables are properly set in your project.

🚀 Features

• Automatic Environment Variable Detection: Scans your codebase to find process.env usages.
• Schema-Based Validation: Supports custom validation schemas for environment variables.
• Auto-Generate .env.example: Keeps .env.example up-to-date with detected variables.
• Fastify Plugin Support: Works seamlessly as a Fastify plugin.

📦 Installation

npm install fastify-auto-env-validator

or using Yarn:

yarn add fastify-auto-env-validator

🚀 Usage

Basic Setup

import Fastify from "fastify";
import envValidator from "fastify-auto-env-validator";

const fastify = Fastify();

// With schema (recommended)
fastify.register(envValidator, {
  schema: {
    DATABASE_URL: { type: "string", required: true },
    PORT: { type: "number", default: 3000 },
  },
});

// Or without schema (auto-detects from code)
// fastify.register(envValidator);

fastify.listen({ port: 3000 }, (err, address) => {
  if (err) {
    console.error(err);
    process.exit(1);
  }
  console.log(`Server running at ${address}`);
});

Auto-Generate .env.example

If the .env.example file is missing, the plugin will create one based on detected environment variables.

⚙️ Options

| Option | Type | Description | | ----------- | -------- | ------------------------------------------------------------------ | | schema | Object | Custom schema to validate environment variables. | | scanPaths | string[] | (Optional) Array of glob patterns to scan for process.env usage. |

✅ Validation Schema

Define a validation schema to enforce required variables:

const schema = {
  DATABASE_URL: { type: "string", required: true },
  API_KEY: { type: "string", required: true },
  PORT: { type: "number", default: 3000 },
};

• type: for documentation only (not enforced by the plugin)
• required: if true, throws if missing
• default: value to use if not set
• validate: custom function (value) => true | string for custom validation

🛠 Development & Testing

Clone the repo and install dependencies:

git clone https://github.com/Dhanapandi555/fastify-auto-env-validator.git
cd fastify-auto-env-validator
npm install

Run tests:

npm test

📜 License

This project is licensed under the MIT License.

Made with ❤️ by Dhanapandi