GENX Backend Coding Test

Backend API for course scheduling and invoice calculation.

Tech Stack

• Node.js
• Express.js
• Zod (validation)
• Dayjs (date handling)
• Jest (unit testing)

Timezone: Asia/Ho_Chi_Minh
Date format: YYYY-MM-DD

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Project Structure

Architecture

• Controllers → Handle HTTP request/response
• Services → Business logic
• middleware -> ValidateRequest
• Validators → Request validation
• Utils → Helper functions
• Tests → Unit tests using Jest

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Installation

Clone repository

git clone https://github.com/truongly2003/BackendTest.git
cd backendtest

Install dependencies

npm install

Run server

npm start

Server runs on:

http://localhost:3000

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Run Tests

npm run test

API Endpoints

1. Generate Class Schedule

POST

http://localhost:3000/api/schedule/generate

Request

{
  "startDate": "2026-01-01",
  "totalClasses": 16,
  "classWeekdays": [1,3],
  "holidays": ["2026-04-30","2026-05-01"],
  "holidayRanges": [["2026-01-26","2026-02-05"]]
}

Response

{
  "endDate": "2026-03-05",
  "fullSchedule": [
    "2026-01-01",
    "2026-01-06",
    "2026-01-08",
    "..."
  ]
}

2. Invoice Calculation

POST

http://localhost:3000/api/invoice/calc

Request

{
  "courseType": "MONTHLY",
  "basePrice": 1500000,
  "months": 2,
  "promoCode": "SAVE10",
  "canceledClasses": 1,
  "refundPerClass": 40000
}

Response

{
  "subtotal": 3000000,
  "discount": 300000,
  "refund": 40000,
  "total": 2660000
}

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Timezone Handling

All date operations use:

Asia/Ho_Chi_Minh

Date format:

YYYY-MM-DD

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Author

Backend Coding Test Ly Van Truong