REST API for URL Shortener

Project roadmap

1. 01

   Set up the Dancer2 app

   ~1h

   Install Dancer2 (with cpanm) and create an app with dancer2 gen. Configure the JSON serializer, and add GET /health returning {"status": "ok"}. Run it with plackup. Done when: curl localhost:5000/health returns the JSON.

2. 02

   Create the database

   ~1h

   Write a schema creating a links table in SQLite: id, code (unique), target URL, created at and clicks (default 0). Connect with DBI (DBD::SQLite) using RaiseError, sharing one connection helper across routes, and create the table at startup if it doesn't exist. Done when: the app starts and the table exists.

3. 03

   Generate short codes

   ~1.5h

   Write a function that makes a random 7-character code from the 62 letters and digits using a good source of randomness (such as Crypt::URandom or Math::Random::Secure), and another that encodes a number in base62 for comparison. Handle the rare collision by trying again when the insert fails on the unique constraint. Done when: tests show codes use only the allowed characters and collisions are retried.

4. 04

   Shorten and redirect

   ~2h

   Add POST /links taking {"url": "..."}: validate it's an http or https URL with a host (with the URI module) and not too long, insert it, and return 201 with the code and the short URL. Add GET /:code, which increases the click count with a single UPDATE and redirects with 302, or returns 404 for unknown codes. Use prepared statements with placeholders for every query. Done when: shortening and redirecting work, and invalid URLs get 400 with a JSON error.

5. 05

   Add stats and tests

   ~2h

   Add GET /links/:code/stats returning the target, creation date and clicks. Write tests with Test::More and Plack::Test (HTTP::Request::Common) using a temporary database: creating links, invalid URLs, redirects with the Location header, click counting, stats and unknown codes. Done when: prove -l t/ passes.

Resources

• DocsDancer2 manual
• DocsDBI on MetaCPAN
• DocsPlack::Test on MetaCPAN
• DocsURI on MetaCPAN
• ArticleBase62 encoding explained