Payroll Software

A comprehensive payroll management system built with Go, designed to handle employee salary calculations, deductions, and payroll processing efficiently.

Table of Contents

• Payroll Software
  • Table of Contents
  • Features
  • Architecture
    • Why This Architecture?
    • Architecture Layers
  • Project Structure
    • Directory Explanations
  • Prerequisites
  • Installation
  • Configuration
  • Database Setup
    • Running Migrations
    • Database Seeding
  • Usage
    • Running the Application
    • Available Make Commands
  • Testing
  • Database Schema
  • Contributing
  • License
  • Support

Features

• Employee management
• Salary calculation and processing
• Tax and deduction management
• Payroll report generation
• User authentication and authorization
• RESTful API endpoints
• Database migration support
• Comprehensive testing suite

Architecture

This project follows a Clean Architecture pattern with clear separation of concerns. The architecture choice is based on several key principles:

Why This Architecture?

1. Familiarity and Experience: This architecture pattern has been proven effective in previous projects, ensuring faster development and maintenance.

2. Separation of Concerns: Each layer has a specific responsibility, making the codebase more maintainable and testable.

3. Scalability: The modular structure allows easy addition of new features without affecting existing functionality.

4. Testability: Clear boundaries between layers make unit testing and integration testing straightforward.

5. Dependency Inversion: Business logic doesn't depend on external frameworks or databases, making the system more flexible.

Architecture Layers

┌─────────────────────────────────────────┐
│                Controllers              │  ← HTTP Handlers
├─────────────────────────────────────────┤
│                Services                 │  ← Business Logic
├─────────────────────────────────────────┤
│              Repositories               │  ← Data Access Layer
├─────────────────────────────────────────┤
│                Database                 │  ← Data Storage
└─────────────────────────────────────────┘

Project Structure

payroll-software/
├── cmd/                    # Application entry points
│   ├── main.go            # Main application
│   └── seed/              # Database seeding
│       └── seed.go
├── internal/              # Private application code
│   ├── controllers/       # HTTP request handlers
│   ├── models/           # Data models and entities
│   ├── dto/              # Data Transfer Objects
│   ├── services/         # Business logic layer
│   ├── repositories/     # Data access layer
│   ├── utils/            # Utility functions
│   └── response/         # API response structures
├── database/
│   └── migrations/       # Database migration files
├── tests/
│   └── e2e/             # End-to-end tests
├── .env                 # Environment variables
├── .env.example         # Environment variables template
├── Makefile            # Build and deployment commands
├── go.mod              # Go module dependencies
├── go.sum              # Go module checksums
└── README.md           # Project documentation

Directory Explanations

• cmd/: Contains the main applications for this project. The main.go file is the entry point of the application, while seed/ contains database seeding utilities.

• internal/: Houses the private application code that shouldn't be imported by other applications.

  • controllers/: HTTP handlers that process incoming requests and return responses
  • models/: Domain entities and data structures
  • dto/: Data Transfer Objects for API communication
  • services/: Business logic and core application functionality
  • repositories/: Data access layer that interacts with the database
  • utils/: Shared utility functions and helpers
  • response/: Standardized API response structures

Prerequisites

• Go 1.19 or higher
• PostgreSQL 12 or higher
• Goose (for database migrations)

Installation

1. Clone the repository:

git clone <repository-url>
cd payroll-software

2. Install dependencies:

go mod download

3. Install Goose for database migrations:

go install github.com/pressly/goose/v3/cmd/goose@latest

Configuration

1. Copy the environment variables template:

cp .env.example .env

2. Update the .env file with your database configuration:

DATABASE_URL=postgres://username:password@localhost:5432/payroll_db?sslmode=disable
DATABASE_URL_TEST=postgres://username:password@localhost:5432/payroll_test_db?sslmode=disable

Database Setup

Running Migrations

The project uses Goose for database migrations. Use the following Makefile commands:

# Run all pending migrations
make up

# Run migrations for test database
make up_test

# Rollback the last migration
make down

# Create a new migration file
make new name=create_employees_table

Database Seeding

Populate the database with initial data:

make seed

Usage

Running the Application

Start the development server:

make run

The application will start on the configured port (default: 8080).

Available Make Commands

• make run - Start the application
• make test - Run end-to-end tests
• make up - Run database migrations
• make up_test - Run migrations for test database
• make down - Rollback last migration
• make new name=<migration_name> - Create new migration
• make seed - Seed database with initial data

Testing

Run the test suite:

make test

The project includes:

• Unit tests for individual components
• Integration tests for API endpoints
• End-to-end tests for complete workflows

Database Schema

The application uses PostgreSQL with the following main entities:

• Users (authentication)
• Employees (employee information)
• Payroll (salary calculations)
• Deductions (tax and other deductions)
• Reports (payroll reports)

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

For support and questions, please open an issue in the GitHub repository.