Venmo

Venmo is a mobile payment service which allows friends to transfer money to each other. It also has some social features like show your friend's payment activities as feed.

This project follows the community best practices in terms of standards, security and maintainability, integrating a variety of testing and code quality tools

• Ruby version 2.7.1

How to use

1. Clone this repo
2. Install PostgreSQL in case you don't have it
3. Create your database.yml and application.yml file
4. bundle install
5. rake db:create
6. rake db:migrate
7. rake db:seed
8. rspec and make sure all tests pass
9. rails s
10. You can now try your REST services!

Code quality

With rake code_analysis you can run the code analysis tool, you can omit rules with:

• Rubocop Edit .rubocop.yml
• Reek Edit config.reek
• Rails Best Practices Edit config/rails_best_practices.yml
• Bullet You can add exceptions to a bullet initializer or in the controller

Entity-Relationship Diagram

Design

Models

• Users: represents a user in the system

• PaymentAccount: represents an account of a User where the balance is stored

• Payment: represents an event of a user transfering money to a friend

• Firendship: represents a friendship relationship between two users

Main services

• FeedService: Is in charge of fetching the feed for a specific user.

• FriendshipService: Is in charge of finding friends up to second degree of a specific user.

• PaymentAccountService: Is in charge of increase or decrease an account balance

• PaymentService: It handles the payment transcation

• MoneyTransferService: Is in charge of transfer money from an external source to an account (mock service)

Notes

• Namespaces api/v1, in routes, were added to handle different versions of the application.
• When a User is created, a PaymentAccount is created and associated to the User.
• If a User stop being friend with another User, User will not see previous payments of the another User in the feed section.

Api doc

Available endpoints

GET balance

GET /api/v1/user/{​id}​/balance

Returns user's balance

Response example:

{
    "user": {
        "balance": 7000.0
    }
}

GET feed

GET /api/v1/user/{​id}​/feed

Returns user's feed. A page parameter is optional

Response example:

{
  "payments": [
    {
        "id": 9,
        "message": "Cavani paid Rashford on February 05, 2021 - bet"
    },
    {
        "id": 4,
        "message": "Martial paid Henderson on February 03, 2021 - Supermarket"
    }
  ],
  "pagy": {
    "page": 1,
    "last": 1,
    "pages": 1,
  }
}

POST payment

POST /api/v1/user/{​id}​/payment

Creates a payment

Parameters:

• friend_id (integer) friend user id
• amount (float) payment amount
• description (text) payment description

Body example:

{
    "friend_id": "1",
    "amount": "10",
    "description": "bet"
}

If the payment was created successfuly, returns 200 status code

Heroku

The app is deployed in Heroku. Check it out on this link: https://venmo-api.herokuapp.com/api/v1

Seeds schema was loaded.

Postman collection

You can get Postman collection here

Seeds

Run rake db:seed to load the following inital friendships

Creates the following payments

Sender: Cavani
Receiver: Rashford
Amount: 100
Description: 'Car'

Sender: Cavani
Receiver: Fred
Amount: 5
Description: 'Dinner'

Sender: Fred
Receiver: Martial
Amount: 10
Description: 'Vacation'

Sender: Martial
Receiver: Henderson
Amount: 150
Description: 'Supermarket'

Sender: Henderson
Receiver: Xisco
Amount: 40
Description: 'Day out'

Sender: Damiani
Receiver: Ruglio
Amount: 5
Description: 'Dinner'

And updates the following balances

Cavani: 7000
Fred: 20
Martial: 500
Damiani: 10
Ruglio: 120

Git workflow

Branches

Develop branch

This branch is the main one because it reflects the work done by the whole team during the development phase in a project. It is used as the base branch until the app is released to production.

Feature branch (feature/x)

This branch’s purpose is to develop a new feature. It has all the progress until the functionality being developed is completed. Pull requests are created from these type of branches and once they have passed the code review process, they have to be merged to develop.

Fix branch (fix/x)

This branch is created in order to fix a bug during development phase.

Enhancement branch (enhancement/x)

This branch is created to add an enhancement during development phase on something that was already merged to the development branch.

Master branch (master)

It reflects the current code deployed in production, therefore, it must be stable. All the new features to be developed are going to have as origin develop and they are going to be merged to master once they are working as expected and approved.