InventorySystem

C# WinForms inventory management application modernized with DevOps practices, including unit testing and CI/CD.

Tech Stack

• Language: C# (.NET 10.0)
• UI Framework: WinForms
• Testing: xUnit
• CI/CD: GitHub Actions
• Containerization: Docker

Version History

Version	Framework	Notes
1.0	.NET 5.0-windows	Original submission
2.0	.NET 10.0-windows	Upgraded for long-term support, DevOps modernization

Upgrade Notes

This project was originally built targeting net5.0-windows, which reached end of life in May 2022. As part of modernizing this project for the use of practicing and testing DevOps principles, the target framework was upgraded to net10.0-windows — the current LTS release — to ensure compatibility with modern tooling, GitHub Actions runners, and current xUnit test frameworks.

Changes made during upgrade:

• Updated <TargetFramework> in .csproj from net5.0-windows to net10.0-windows

• Resolved NuGet package compatibility issues introduced by the framework change

• Added a separate xUnit test project targeting net10.0-windows to match the main project

• The WinForms UI layer is not containerized (Windows-only dependency)

• InventorySystem.Logic contains the cross-platform business logic

• All 21 tests pass inside the container on Linux

Project Structure

InventorySystem/
├── InventorySystem-EmilyCarter.sln        # Solution file
│
├── InventorySystem-EmilyCarter/           # Main project
│   ├── dataParts/
│   │   └── SelectionMode.cs
│   ├── helper/
│   │   └── validator.cs                   # Validation logic
│   ├── model/
│   │   ├── Inhouse.cs
│   │   ├── Inventory.cs
│   │   ├── Outsourced.cs
│   │   ├── Part.cs
│   │   └── Product.cs
│   ├── AddPart.cs
│   ├── addProducts.cs
│   ├── InventoryMain.cs
│   ├── modifyParts.cs
│   ├── ModifyProduct.cs
│   ├── Program.cs
│   └── InventorySystem_EmilyCarter.csproj
│
└── InventorySystem.Tests/                 # xUnit test project
    ├── ValidatorTests.cs                  # Unit tests for validator logic
    └── InventorySystem.Tests.csproj

Docker

This project includes a Docker container for running the logic layer and tests in a cross-platform environment.

Build

docker build -t inventorysystem:2.0 .

Run Tests

docker run --rm inventorysystem:2.0 dotnet test InventorySystem.Logic.Tests/InventorySystem.Logic.Tests.csproj --verbosity normal

Running the App

dotnet run --project InventorySystem-EmilyCarter/InventorySystem_EmilyCarter.csproj

Running Tests

dotnet test InventorySystem.Tests/InventorySystem.Tests.csproj

Test Coverage

Test	Description	Status
ValidateMinMaxValues_ValidInputs_ReturnsTrue	Valid min/max returns true	✅ Passing
ValidateMinMaxValues_MinEqualsMax_ReturnsTrue	Min equal to Max is allowed	✅ Passing
ValidateMinMaxValues_MinGreaterThanMax_ReturnsFalse	Min greater than Max fails	✅ Passing
ValidateMinMaxValues_NegativeMax_ReturnsFalse	Negative Max fails	✅ Passing
ValidateMinMaxValues_NegativeMin_ReturnsFalse	Negative Min fails	✅ Passing
ValidateMachineID_ValidInput_ReturnsTrue	Contains Valid String	✅ Passing
ValidateMachineID_EmptyInput_ReturnsFalse	Is not null	✅ Passing
ValidateMachineID_NegativeInput_ReturnsFalse	Does not contain negative int	✅ Passing
ValidateMachineID_WhitespaceInput_ReturnsFalse	Does not contain whitespace	✅ Passing
ValidateCompanyName_ValidInput_ReturnsTrue	Company Name Matches Input/Output	✅ Passing
ValidateCompanyName_NullInput_ReturnsFalse	Is not null	✅ Passing
ValidateCompanyName_ContainsNumbers_ReturnsFalse	Does not contain integers	✅ Passing
ValidateCompanyName_ExceedsMaxLength_ReturnsFalse	Input does not exceed max length	✅ Passing
ValidateCompanyName_BelowMinLength_ReturnsFalse	Input below Min Length	✅ Passing
ValidateCompanyName_ValidInputWithWhitespace_ReturnsTrueAndTrims	Happy Path and returns trims	✅ Passing

What I Learned

• Separation of concerns — extracting pure logic from WinForms-coupled classes to make them unit testable
• xUnit testing fundamentals — Arrange/Act/Assert pattern
• Professional solution structure with a separate test project
• Framework migration from .NET 5.0 to .NET 10.0
• Git workflow — feature branches, pull requests, and clean commit history
• [Theory] vs [Fact] — when to test multiple inputs with a single test method
• Docker containerization — why WinForms cannot be containerized and how to isolate the logic layer
• Cross-platform development — the difference between net10.0-windows and net10.0
• Class libraries — separating reusable logic into a .dll for use across projects
• .dockerignore — keeping containers lean by excluding build artifacts
• Static state in tests — why shared collections cause test pollution and how constructors solve it
• Real bug fixing — improving DeletePart to return accurate success/failure results