A submission for DCUBE's TAP assessment 2023, created by Remus Kwan.

• Shortening of long URLs into shorter, friendlier URLs.
• Short URLs can be shared, and redirect to original URL when short URL is accessed.
• User-managed URLs for creating, viewing and deleting their own URLs.
• Password authentication with encryption during user sign-in.
• User sessions stored as cookies.

Access the live demo at https://short-re.vercel.app

• React.js as a versatile front-end frameworks for building web interfaces
• Next.js as a React framework for building full-stack applications with robust backend and web services
• tRPC for building type-safe web applications with TypeScript
• Prisma as a Node.js and TypeScript ORM.
• CockroachDB as a cloud-enabled relational database for persisting data across system reboots
• Vercel as a CI/CD tool for deploying the application end-to-end
• OGP's Starter Kit as a kickstart for the project.

The database contains two tables, User and URL. URLs with userIds can be managed by users when they are logged in.

The following diagram illustrates the general flow E2E of several functionalities of the application.

URLs are assigned a unique hash generated using a hash-and-salt algorithm (SHA256), which is then encoded for display. For the purposes of this project, the encoding is in base62. We then take the first 6-8 letters to form the shortened URL.

This approach poses several problems:

• If multiple users enter the same URL, they can get the same shortened URL

To avoid this, initial URLs are appended with a unique identifier (32-character random string) before it is hashed and encoded.

export const shortenURL = (originalURL: string): string => {
  const uniqueString = `${originalURL}-${randomUUID()}`
  // Hash the unique string
  const hash = createHash('sha256').update(uniqueString).digest()
  // Encode in base-62
  const encoded = encodeBase62(hash)
  // Trim to a fixed length
  const shortened = encoded.slice(0, 8)

  return shortened
}

Due to time constraints, certain functionalities have yet to be implemented:

• Password validation to ensure accounts are created with strong passwords.
• Search/filter functionality for user-created URLs.
• Implement soft delete for user and URLs
• Migrate to NoSQL (eg. MongoDB, DynamoDB) due to the relatively few relations and the potential performance improvement
• Standalone Key Generation Store that generates random strings beforehand and stores them in a database
• Forgot password + email verification
• Account management such as updating profile, deleting account etc.
• Authentication using OAuth providers (eg. Google, Apple, GitHub etc.)
• Distinct look and feel to the application.

• Database partitioning/sharding for scalability
• Cache to store frequently accessed URLs

npm i

cp .env.example .env

# Assumes that you have previously copied .env.example to .env
npm run setup

npm run dev

npm run build      # runs `prisma generate` + `prisma migrate` + `next build`
npm run db:reset   # resets local db
npm run dev        # starts next.js
npm run setup      # starts cockroach db + runs migrations + seed
npm run test-dev   # runs e2e tests on dev
npm run test-start # runs e2e tests on `next start` - build required before
npm run test:unit  # runs normal Vitest unit tests