As requested, this is a very simple Messenger API. With two available endpoints, this API can create new text-based messages between two users, and return messages for a given recipient.

You may review the feature work for these endpoints in this pull request.

Timeframe:

• ~3 hours coding
• ~1 hour planning + documentation

• Users (senders and recipients) have unique integer IDs that will be passed to the API endpoints as parameters
• Anonymous messages are not allowed (there must be a sender_id given)
• Empty messages are not allowed (there must be content given)
• Authorization, Authentication and Registration can be ignored (this is a global API that can be leveraged by anyone, security is not a concern)

Request
Verb + Path: POST http://localhost:3000/api/v1/messages
Body:

{
"sender_id": 1234, 
"recipient_id": 5678, 
"content": "Don't worry, about a thing"
}

Response
Status: 201 Created
Body:

{
    "response": "Created"
}

Request
Verb + Path: GET http://localhost:3000/api/v1/messages
Body:

{
"sender_id": 1234, 
"recipient_id": 5678, 
"limit": "100"
}

Response
Status: 200 OK
Body:

{
    "data": [
        {
            "id": "5",
            "type": "message",
            "attributes": {
                "sender_id": 1234,
                "recipient_id": 5678,
                "content": "Don't worry, about a thing",
                "created_at": "2021-08-27T13:55:26.670Z"
            }
        },
        {
            "id": "4",
            "type": "message",
            "attributes": {
                "sender_id": 1234,
                "recipient_id": 5678,
                "content": "Don't worry, about a thing",
                "created_at": "2021-08-27T00:17:17.236Z"
            }
        },
        {
            "id": "1",
            "type": "message",
            "attributes": {
                "sender_id": 1234,
                "recipient_id": 5678,
                "content": "This is a message for you-ooh-ooh",
                "created_at": "2021-08-26T22:16:28.820Z"
            }
        }
    ]
}

• Ruby 2.7.2
• Rails 6.0.4.1
• PostgreSQL 13.4
• Gems:
  • RSpec
  • Shoulda-Matchers
  • SimpleCov
  • jsonapi-serializer

To setup these endpoints locally:

1. clone this repo to your local machine
2. run bundle install
3. run rails db:{create,migrate} to setup the database
4. run rails s and navigate to http://localhost:3000 with the desired endpoint for get requests, and/or use a tool like Postman for post requests.

Given additional time, here's what I'd like to work on:

• Refactor! Cleanup methods for increased readability, DRY-ness and SRP
• Add an ErrorSerializer to return 400 responses in the JSON:API convention
• Refactor to provide more detailed error responses (which field is mising, e.g.)
• Include additional edge case handling:
  • Set a character limit on message content to ensure it fits within the database
• Leverage a gem like FactoryBot to cleanup test setup