Chomchob Backend Testing

Thank you for interest in ChomCHOB

We have 2 part for testing your coding skill. When you done this task you need to created repository like in "example submission" folder on your github repository.

This test contain with 2 part.

1. Programming
2. Database

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Note

• You have 7 day after receive email to complete this test.

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Programming

Simple Wallet Api

Description

You need to create simple wallet api for transfer cryptocurrency between user A to user B. Also have admin ability to manage both cryptocurrency and exchange rate.

Requirement

• Admin can increase and decrease user cryptocurrency balance.
• Admin can see all total balance of all cryptocurrency.
• Admin can add other cryptocurrency such XRP, EOS, XLM to wallet.
• Admin can manage exchange rate between cryptocurrency.
• User can transfer same cryptocurrency to other.

Example

UserA transfer 10 ETH to UserB so UserB will recieve 10 ETH

• User can transfer cryptocurrency to other with difference currency such ETH to BTC with exchange rate.

Example

UserA transfer 1000 ETH to UserB with exchange rate ETH/BTC equal to 0.05 so UserB will recieve 50 BTC

• It ok whether cryptocurrency have decimal or not.

Technical Detail

• This API need to be written with Nodejs.
• You can use any nodejs web framework but we prefer express.
• You can use any tool or library to help you build API.
• Database we prefer mariadb, but if you think other database is suitable it fine to use that db.
• Please provide us POSTMAN collection and environment(if needed) in JSON format.
• This is not decentralized wallet so no need to worry about blockchain stuff.
• If some of detail or requirement are ambiguous, we so sorry about that. And feel free to use your creative thinking to do that stuff.

Bonus

• TDD
• Deploy to cloud such as aws or gcp.

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Database

You have assign to design Database for sale item code system for game this provide for customer who want to buy code for using in game.

Detail

• Item for sale must have product name, product detail, sale price, open sale date, end sale date.
• When customer already bought an item, customer will receive code (code can be created or create after bought).
• item have a discount promotion period with specific date time for example normal price is 150 baht and have a promotion on January and set discounted price to 100 baht.

Bonus

• item may sale in bundle type for example sale two difference character skin set in special price or sale five gachapon box (for random item) in special price.

Objective

• Create database in form of model from sequelize.
• Create Entity Relationship Diagram (ERD) and provide us with picture or pdf format. You can create ERD with any tool you want even handwriting is fine.
• Please provide us description why you design database like this, for clearly understand.

Example Sequelize Model

// Store User
const User = sequelize.define('User', {
  id: Sequelize.INTEGER,
  name: Sequelize.STRING,
  age: Sequelize.INTEGER,
})

User.associate = (models) => {
  User.hasMany(UserCard, { foreignKey: 'user_id' })
}

// Store User credit card 
const UserCard = sequelize.define('UserCard', {
  id: Sequelize.INTEGER,
  user_id: Sequelize.INTEGER,
  mask_pan: Sequelize.STRING,
})

UserCard.associate = (models) => {
  UserCard.belongsTo(User, { foreignKey: 'user_id' })
}

Example Entity Relationship Diagram

Hint

• You can see database part in thai language for better understanding.