LinkShortener

A full-stack URL shortener built with ASP.NET Core, PostgreSQL, and React with authentication, rate limiting, and a fully containerized, CI-tested, deployed pipeline.

Live demo: linkshortner-3hzn.onrender.com

Free-tier hosting note: the backend spins down after 15 minutes of inactivity, so the first request after a while may take 30–60 seconds to wake up.

Features

• Shorten any valid URL into a short, shareable code
• Optional link expiry (expiresInDays)
• Click tracking per link
• User accounts: register/login with JWT auth; each user's links are tied to their account
• Rate limiting on link creation to prevent abuse
• Fully typed React + TypeScript frontend with a custom "departure board" UI
• Dockerized backend + Postgres, with a docker-compose setup for local development
• CI pipeline (GitHub Actions) running the full test suite including real Postgres via Testcontainers on every push

Tech stack

Backend: C# / ASP.NET Core minimal API, Entity Framework Core, PostgreSQL (Npgsql), JWT authentication, System.Threading.RateLimiting

Frontend: React, TypeScript, Vite

Testing: xUnit, Testcontainers (real Postgres per test run), FluentAssertions

Infra: Docker, Docker Compose, GitHub Actions, Render (hosting)

Project structure

LinkShortner/
├── LinkShortner/ # ASP.NET Core API
│ ├── Endpoints/ # Minimal API endpoint definitions
│ ├── Models/ # EF Core entities + request/response records
│ ├── Data/ # DbContext
│ ├── Services/ # TokenService, ShortCodeGenerator
│ ├── Migrations/ # EF Core migrations
│ └── Dockerfile
├── LinkShortener.Tests/ # xUnit integration + unit tests
├── linkshortener-frontend/ # React + TypeScript frontend
├── .github/workflows/ # CI pipeline
└── docker-compose.yml # Local dev: Postgres + API together

Running locally

Prerequisites

• .NET 10 SDK
• Node.js + npm
• Docker Desktop

1. Start Postgres + API via Docker Compose

docker compose up -d --build

This builds the API image and starts it alongside a Postgres container. Copy .env.example to .env first and fill in real values (JWT signing key, DB password) see that file for the required variables.

2. Run database migrations

cd LinkShortner
dotnet ef database update

3. Run the frontend

cd linkshortener-frontend
npm install
cp .env.example .env   # set VITE_API_BASE to your local backend URL
npm run dev

Visit http://localhost:5173.

Running tests

cd LinkShortener.Tests
dotnet test

Tests spin up a real, throwaway Postgres container via Testcontainers: no manual database setup required, and no shared state between runs. Requires Docker to be running.

API overview

Method	Endpoint	Auth required	Description
POST	/auth/register	No	Create an account, returns a JWT
POST	/auth/login	No	Log in, returns a JWT
POST	/shorten	Yes	Create a short link
GET	/{code}	No	Redirect to the original URL, increments click count
GET	/api/urls/{code}	No	Look up a link's metadata
GET	/api/urls/mine	Yes	List the authenticated user's own links

Deployment

Deployed on Render: PostgreSQL, the API (as a Docker web service), and the frontend (as a static site) each run as separate Render services. Environment variables (connection strings, JWT signing key, CORS origins, rate limit settings) are configured per-service in Render's dashboard, not committed to source.

What this project was built to practice

• Minimal API design in ASP.NET Core
• EF Core migrations and relational modeling
• JWT-based authentication from scratch
• Integration testing with real infrastructure (Testcontainers) rather than mocks
• CORS, rate limiting, and other production-readiness concerns
• CI/CD and containerized deployment end-to-end