ahmetcelikezer / case-study-exchange

Exchange App

Installation

First, we need to create .env file in the root directory of the project. Required variables are defined .env.dist file. You can copy it to .env file and edit it.

You can also use Makefile make setup-dev command for the development environment.

Then we need the install depended on packages with the following command:

> yarn install

Required database can be run via docker-compose if docker already installed inside your system.

> docker-compose up -d

This command will run both test and development database for your local environment.

If you want to run this application on production environment, you should use your own database and define it's connection in .env file.

To migrate database to the latest version, run the following command:

> yarn mikro-orm migration:up

To fill database with some data, run the following command:

> yarn mikro-orm seeder:run

and to run the application, run the following command:

# for development environment (sql logging and more is enabled)
> yarn start:dev

# for production environment
> yarn start

How TO Test

You can find Postman collection in root directory exchange_app.postman_collection.json file.

In Postman collection, case study task endpoints are under Task Requests folder.

Login and Register endpoints returns token on success response, please add this token as a Bearer token. If you request without token, you will get 401 error.

You can login with default credentials:

Default Credentials

E-mail	Password
[e-mail]	123456
[e-mail]	123456
[e-mail]	123456
[e-mail]	123456
[e-mail]	123456

Description

• In this project, you can; insert initial data into the database using ORM's out-of-box feature seeder.
• To update (register) sock price hourly basis, cron job is always running with your application.

Users can buy and sell stocks for any amount they want.

When users want to sell stocks after they send a sell request to a specified endpoint with backend will create sell transactions that are ready to buy for buyers. The stock price will be deposited after the buyer completes the open transaction.

Note: I don't use there OPTIMISTIC_LOCK, normally to make transactions safe, we need the lock data to prevent concurrent transaction problems.

When users want to buy some stocks, they will send requests with the target stock and the amount of the stocks they want to buy. The system automatically sells the cheapest stocks to the user if money is enough.

Features

Seed Database

You can seed database with fake & pre-defined data using yarn mikro-orm seed:run command.

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Cron Job

In this project, the cron job was used to create stock prices. This CRON job executes the script every hour. This script reads the latest transaction of each stock's transaction taken by the user and set its rate(price) to the new Stock Price and inserts it.

That means each stock has an hourly price log, we only create hourly stock price value but we don't use this value anywhere yet in this project. But in the future, we can use these price logs to draw hourly price charts.