@wuyuchentr/env-validator

Validate .env variables against expected types, patterns, and choices at startup. Fail fast when configuration is wrong.

Install

npm install -g @wuyuchentr/env-validator

Quick start

Create env-validator.config.js in your project root:

module.exports = {
  NODE_ENV: { type: 'string', pattern: /^(dev|staging|prod)$/, required: true },
  PORT: { type: 'port', required: true },
  DATABASE_URL: { type: 'url', required: true },
  DEBUG: { type: 'boolean', default: 'false' },
  LOG_LEVEL: { type: 'string', choices: ['debug', 'info', 'warn', 'error'], default: 'info' },
};

Run:

npx @wuyuchentr/env-validator

Schema options

| Option | Type | Description | |-----------|------------|-------------| | type | string | One of: string, number, boolean, email, url, port | | required | boolean | Whether the variable is required (default true) | | default | any | Fallback value when not set (implies required: false) | | pattern | RegExp | Custom regex pattern to match against | | choices | string[] | List of allowed values | | message | string | Custom error message |

Usage as library

const { validate } = require('@wuyuchentr/env-validator');

const { errors, env } = validate(process.env, {
  PORT: { type: 'port', required: true },
});

if (errors.length) {
  console.error('Invalid config:', errors);
  process.exit(1);
}

console.log('Parsed PORT:', env.PORT); // number