URL Shortener

The project as it is hosts a webserver serving a web-based frontend at localhost:8080, it's just a quick no-framework wrapper around the API, which is at /api. The API itself exposes /api/shorten (PUT) and /api/:shortId (GET) as outlined in the challenge, and both endpoints can accept/produce plaintext (with Content-Type: text/plain;charset=utf-8) or JSON (with Content-Type: application/json).

The webserver itself is built using WAI, Warp, and Servant, and (currently) talks to a Postgres database. The shortened URLs are based on the SHA256 hash, so shortening the same URL twice gives the same code instead of adding a duplicate.

How to run/build/test

The postgres server expects a database specified by the connection string in pgConnStr, tests expect the same from pgTestConnStr. System-level dependencies are handled by Stack and Nix, so assuming a system with Nix, nix-shell --run 'stack {run/build/test} will take care of the rest!

What could be improved

• If it were a bigger project, the frontend should probably be redone using some frontend framework, perhaps React with Typescript or purescript-halogen.
• The URL validation on the server is fairly coarse - it probably shouldn't accept nonsense like aaaaaaa:///////:///$$ or even just ://
• The pgConnStr and pgTestConnStr files are a bit hacky; they should probably be moved to a "real" config file format, but that'd have to pull in parsers and such

Attribution

The icon is based off of the Twemoji chain-link emoji.