NLW Expert (NodeJS)

Project

This project was developed as part of the NLW Expert event organized by Rocketseat. It is an API for a real-time voting system where users can create polls and cast their votes. The system dynamically generates a ranking among the poll options and updates the votes in real-time.

Project Diagram

Features

• Users can create polls;
• Community members can vote on polls;
• Real-time updating of votes and ranking;
• API-based architecture for easy integration;

Requirements

• Docker;
• NodeJS;

Setup

• Clone the repository

git clone https://github.com/alexandrecpedro/real-time-voting-system.git

• Install dependencies

 npm install

• Setup PostgreSQL and Redis

 docker compose up -d

• Copy .env.example file

 cp .env.example .env

• Run application

 npm run dev

• Test it!
  • Hoppscotch.
  • Postman.

HTTP

POST /polls

Create a new poll.

Request body

{
  "title": "Qual a melhor linguagem de programação?",
  "options": ["JavaScript", "Java", "PHP", "C#"]
}

Response body

{
  "pollId": "194cef63-2ccf-46a3-aad1-aa94b2bc89b0"
}

GET /polls/:pollId

Return data from a single poll.

Response body

{
  "poll": {
    "id": "e4365599-0205-4429-9808-ea1f94062a5f",
    "title": "Qual a melhor linguagem de programação?",
    "options": [
      {
        "id": "4af3fca1-91dc-4c2d-b6aa-897ad5042c84",
        "title": "JavaScript",
        "score": 1
      },
      {
        "id": "780b8e25-a40e-4301-ab32-77ebf8c79da8",
        "title": "Java",
        "score": 0
      },
      {
        "id": "539fa272-152b-478f-9f53-8472cddb7491",
        "title": "PHP",
        "score": 0
      },
      {
        "id": "ca1d4af3-347a-4d77-b08b-528b181fe80e",
        "title": "C#",
        "score": 0
      }
    ]
  }
}

POST /polls/:pollId/votes

Add a vote to specific poll.

Request body

{
  "pollOptionId": "31cca9dc-15da-44d4-ad7f-12b86610fe98"
}

WebSockets

ws /polls/:pollId/results

Number of votes of one poll.

Message

{
  "pollOptionId": "da9601cc-0b58-4395-8865-113cbdc42089",
  "votes": 2
}