TreeLink

This project is meant to be a lightweight clone of a popular website where users can store a list of personal links.

It is built using HTTP4S for the server, Circe for encoding, and Doobie for database access. The database is a MySQL instance deployed on PlanetScale (heard good things about it, wanted to try it out), but if you want to use a different database, just change the driver.

If you have any recommendations or pointers, please submit a PR or an Issue.

Endpoints

POST /users Creates a user

Body

{ "username": String }

Response

{ "id": Int, "username": String, "createdDate": String }

GET /users/{username} Gets a user

Response

{ "id": Int, "username": String, "createdDate": String }

POST /tree Creates a new link

Body

{ "userId": Int, "link": String }

Response

{ "id": Int, "link": String, "userId": Int, "createdDate": String }

GET /tree/{username} Gets user's links

Response

[ String, String, ... ]

GET /hello - Test endpoint

Response

{ "hi": "hello world!" }

Notes and Learnings

• It can be difficult to extract optionals from the Doobie SQL transactions in DatabaseService.scala and do the error handling in Main.scala. For example, in the case of /tree/{username} we simply check for an empty list to determine the HTTP response code, instead of using pattern matching on an Optional, which would be ideal.
• Implicit vals are automatically passed as arguments to the demanding methods. I believe they match on the object's type.
• By default, Doobie absorbs select * columns into an object (such as a User in this project) the order they are received. You might need to query columns in a specific order, or reorder the case class definition to fit the database schema.