Environment Setup

Prepare the environment for hands-on learning by running code directly. Each step takes just a few minutes.

Required Prerequisites

1. .NET 10.0 SDK

The .NET SDK is required for building and running all projects.

# Version check
dotnet --version
# Example output: 10.0.100

# Install (Windows)
winget install Microsoft.DotNet.SDK.10

# Install (macOS)
brew install --cask dotnet-sdk

# Install (Linux - Ubuntu)
sudo apt-get update && sudo apt-get install -y dotnet-sdk-10.0

2. IDE Setup

VS Code + C# Dev Kit

• Install the C# Dev Kit extension

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Project Setup

Clone Source Code

# Clone the Functorium project
git clone https://github.com/hhko/Functorium.git
cd functorium

Verify Build

# Build the entire solution
dotnet build Functorium.slnx

# Run all tests
dotnet test --solution Functorium.slnx

Run Individual Projects

# Build the entire tutorial
dotnet build specification-pattern.slnx

# Test the entire tutorial
dotnet test --solution specification-pattern.slnx

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Default Using Statements

Default using statements used in projects:

using Functorium.Domains.Specifications;

When using Expression Specification:

using System.Linq.Expressions;
using Functorium.Domains.Specifications;

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How to Run Each Project

Running Tests

# Test the entire tutorial
dotnet test --solution specification-pattern.slnx

# Run specific tests only
dotnet test --solution specification-pattern.slnx --filter "IsSatisfiedBy_ReturnsTrue_WhenProductIsActive"

Full Solution Test

# From the solution root
dotnet test --solution specification-pattern.slnx

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Project Structure

Each tutorial project has the following structure:

01-First-Specification/
├── FirstSpecification/                    # Main project
│   ├── FirstSpecification.csproj          # Project file
│   └── Specifications/                    # Specification classes
│       └── ActiveProductSpec.cs
│
└── FirstSpecification.Tests.Unit/         # Test project
    ├── FirstSpecification.Tests.Unit.csproj
    ├── xunit.runner.json
    └── ActiveProductSpecTests.cs

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Troubleshooting

.NET SDK Not Recognized

# Check PATH environment variable
echo $PATH

# For Windows, add the following path to system environment variables
# C:\Program Files\dotnet

IntelliSense Not Working in IDE

1. Restart the IDE
2. Run dotnet restore
3. Delete the .vs or .vscode folder and restart

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FAQ

Q1: Is .NET 10.0 SDK mandatory?

A: Yes. All projects in this tutorial target .NET 10.0. Some Functorium library APIs require .NET 10.0 or later, so the build may fail on earlier versions.

Q2: Can individual projects be built/tested independently?

A: Yes, running dotnet test from each chapter’s project folder tests that project independently. The full solution build is performed with dotnet build Functorium.slnx.

Q3: Which IDE should I use?

A: Use whichever is comfortable among VS Code + C# Dev Kit, JetBrains Rider, or Visual Studio 2022. Any IDE will work as long as the C# development environment is set up and .NET 10.0 SDK is installed.

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Next Steps

Environment setup is complete. Now let’s look at the big picture of what problems the Specification pattern solves.

-> 0.3 Specification Pattern Overview