auto-cors-diagnose

Automatic CORS issue analyzer with clear explanations and actionable solutions.

auto-cors-diagnose is a CLI and Node.js library that helps developers automatically analyze CORS (Cross-Origin Resource Sharing) issues.
It performs a preflight OPTIONS request and inspects response headers to determine whether the API supports cross-origin access — and if not, it provides clear explanations and solutions.

Perfect for:

• Frontend developers dealing with CORS errors
• Backend developers verifying API configuration
• QA engineers validating endpoints
• Students learning CORS behavior

✨ Features

• 🔍 Automatic CORS analysis for any API endpoint
• ⚠ Detects missing or invalid CORS headers
• 🧠 Provides actionable recommendations
• 💻 Works as both CLI and library
• 🚀 Lightweight and dependency-free

📦 Installation

Install globally:

npm install -g auto-cors-diagnose

Or use NPX without installation:

npx auto-cors-diagnose <url>

💻 CLI Usage

Check CORS configuration of an API:

npx auto-cors-diagnose https://dummyjson.com/products

Example output:

{
  "status": "OK",
  "details": "CORS headers detected.",
  "rawHeaders": {
    "access-control-allow-origin": "*",
    "access-control-allow-methods": "GET,HEAD,PUT,PATCH,POST,DELETE"
  }
}

Failure example:

{
  "status": "CORS_BLOCKED",
  "reason": "missing-allow-origin",
  "details": "Access-Control-Allow-Origin header not found.",
  "solution": "Add 'Access-Control-Allow-Origin: *' or specify allowed domains."
}

🧑‍💻 Library Usage (Node.js)

import { diagnoseCors } from "auto-cors-diagnose";

const result = await diagnoseCors("https://dummyjson.com/products");
console.log(result);

📁 Project Structure

auto-cors-diagnose
├─ bin/                 # CLI launcher
├─ dist/                # Compiled JavaScript
├─ src/                 # TypeScript source code
│  ├─ core/
│  ├─ utils/
│  └─ cli.ts
└─ tests/               # Vitest tests

🧪 Running Tests

npm run test

🤝 Contributing

Contributions are welcome! Please use:

dev branch → development

feat/<feature-name> → new features

📄 License

This project is released under the MIT License © 2025 Kikuk Afandi.