Rental Repairs Modernization Project

This repository demonstrates a systematic modernization of a legacy .NET application into a clean, maintainable, and extensible solution. The project highlights Clean Architecture, Domain-Driven Design (DDD), CQRS, and MediatR, with GitHub Copilot in agent mode assisting the process.

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🧭 Repository Structure

• / — Original codebase (preserved for reference and comparison)
• src/ — Modernized solution following Clean Architecture:
  • Domain/ — Core business logic, entities, value objects, domain events
  • Application/ — Use cases, CQRS handlers, DTOs, validation
  • Infrastructure/ — EF Core persistence, external services, repositories
  • WebUI/ — Razor Pages presentation layer

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🛠 Technologies

• .NET 8
• MediatR for CQRS
• Entity Framework Core for persistence
• Mapster for DTO mapping
• FluentValidation for input validation
• xUnit for testing

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🎯 Objectives

1. Demonstrate a step-by-step migration process using AI with human-in-the-loop approvals
2. Apply Clean Architecture and DDD principles to a legacy project
3. Showcase the benefits of the new architecture compared to the original

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📄 Documentation

• docs/domain-overview.md — Business domain concepts, entities, and workflows
• docs/migration-process.md — Migration strategy and execution plan
• docs/architecture-comparison.md — Benefits of the new architecture

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🚀 Getting Started

Prerequisites

Before running the application, ensure you have the following installed:

• .NET 8 SDK (8.0 or later)
• SQL Server or SQL Server Express (Download here)
  • Alternative: SQL Server LocalDB (included with Visual Studio)
• Visual Studio 2022 (recommended) or Visual Studio Code
• Git for cloning the repository

Quick Start (Modernized Application)

1. Clone the repository

   git clone https://github.com/akhmelevtsov/DemoRentalRepairsWebAPI.git
   cd DemoRentalRepairsWebAPI

2. Navigate to the modernized solution

   cd src

3. Restore NuGet packages

   dotnet restore

4. Update database connection string (if needed)

   Edit src/WebUI/appsettings.json:

   {
     "ConnectionStrings": {
       "DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=RentalRepairsDb;Trusted_Connection=true;MultipleActiveResultSets=true;"
     }
   }

   For SQL Server Express, use:

   "DefaultConnection": "Server=.\\SQLEXPRESS;Database=RentalRepairsDb;Trusted_Connection=true;MultipleActiveResultSets=true;"

5. Run the application

   cd WebUI
   dotnet run

6. Open your browser

   Navigate to: https://localhost:5001 or http://localhost:5000

First Run Setup

The application will automatically:

• ✅ Create the database if it doesn't exist
• ✅ Apply any pending migrations
• ✅ Log initialization status to console

Default Test Data

To get started quickly, you can register test users:

1. Property Manager (Superintendent)

   • Click "Register" and create an account
   • Register a property with sample data:
     • Property Code: test-property
     • Units: 101, 102, 103, 201, 202, 203

2. Tenant

   • Register as a tenant for unit 101 in test-property
   • Submit repair requests to test the workflow

3. Worker

   • Register as a worker to receive work assignments

Running Legacy Version (Comparison)

To compare with the original legacy implementation:

1. Navigate to legacy WebMVC

   cd Demo.RentalRepairs.WebMvc
   dotnet run

2. Navigate to legacy WebAPI

   cd Demo.RentalRepairs.WebApi
   dotnet run

Running Tests

Run all tests:

cd src
dotnet test

Run specific test projects:

# Domain tests
dotnet test Domain.Tests/

# Application tests  
dotnet test Application.Tests/

# Integration tests
dotnet test WebUI.Tests/

Generate test coverage report:

dotnet test --collect:"XPlat Code Coverage"

Database Management

Reset database:

cd src/WebUI
dotnet ef database drop --force
dotnet run  # Will recreate on startup

Apply migrations manually:

cd src/Infrastructure
dotnet ef database update --startup-project ../WebUI

Troubleshooting

Common Issues

1. Database Connection Errors

• Verify SQL Server is running
• Check connection string in appsettings.json
• Ensure database permissions are correct

2. Port Already in Use

# Check what's using the port
netstat -ano | findstr :5001

# Kill the process (replace PID)
taskkill /PID <process_id> /F

3. SSL Certificate Issues

# Trust the development certificate
dotnet dev-certs https --trust

4. Build Errors

# Clean and rebuild
dotnet clean
dotnet restore
dotnet build

Enable Detailed Logging

Add to appsettings.Development.json:

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "Microsoft.EntityFrameworkCore": "Information"
    }
  }
}

Configuration Options

The application supports various configuration options in appsettings.json:

• Caching: Enable/disable in-memory caching
• Email Notifications: Configure SMTP or mock email provider
• Logging: Serilog configuration for file and console output
• Security: Authentication and authorization settings

What's Working Now

✅ Complete Clean Architecture Implementation

• Domain layer with DDD patterns
• Application layer with CQRS and MediatR
• Infrastructure layer with EF Core
• Presentation layer with Razor Pages

✅ Core Business Functionality

• Property registration and management
• Tenant request submission and tracking
• Worker assignment and task completion
• User authentication and authorization

✅ Comprehensive Testing

• 50+ unit and integration tests
• Domain logic validation
• End-to-end workflow testing

✅ Production-Ready Features

• Security headers and authentication
• Logging and health checks
• Error handling and validation
• Performance optimizations

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