ToDo API in Clojure

The intent of this project is to familiarize myself with Clojure. Not only the language, but also the development process.

Running

1. Start docker docker compose up -d
2. Run make run
3. It will run on localhost:3000

REPL Development

In deps.edn there is an alias dev that allow to run the application and interacts with XTDB.

Start the REPL with the dev alias and run:

(start)

It will start the server on port 3000 and hot-reload. However, the hot reload doesn't not work so well so some changes require restarting the REPL.

To stop the server, run:

(stop)

XTDB

Also, you can interact with the XTDB node using

xt/submit-tx and xt/q. They are already imported in the namespace and there is a global node.

Querying all TODOs:

(xt/q node '(from :todos [*]))

API

This API is composed of the following endpoints:

• GET /todos
• GET /todos/:id
• POST /todos
• DELETE /todos/:id
• PATCH /todos/:id

GET /todos/:id

An TODO object looks like:

{
  "description": "my description",
  "completed": false,
  "title": "My task 2",
  "xt/id": "d57087f9-a23f-4e0c-bc9b-1e166dcf75c1"
}

POST /todos

It excepts a payload with title and description:

{
  "title": "My task 5",
  "description": "my description"
}

It creates an object in the todos table with completed = false and random UUID to xt/id

PATCH /todos/:id

This endpoint allow to update the title, description, and the completed flag:

{
  "completed": false,
  "title": "My new task title",
  "description": "My new task description" 
}

Decisions

I opted for deps.edn over lein to keep things simple. Lein reminds me a lot of Java projects and after having great DX with Node ecosystem, I want things at least simple.

Using Compojure because seems the most straightforward way of building web applications. However, the reload on file change was tricky to make it work. ring.middleware.reload favors variable references and I didn' want to have global variables.

XTDB v2 was used only because of XTQL. I could manage to do all operations with it instead SQL.