Blun.Build.Tasks.BuildTimeStamp 1.0.1

Blun.Build.Tasks.BuildTimeStamp

📋 Introduction

A small MSBuild Task that inserts a build timestamp into assembly metadata during the build process. This allows applications to read the build time at runtime.

The package adds an assembly-level System.Reflection.AssemblyMetadataAttribute with key Blun.Build.Tasks.BuildTimeStamp_UTC and an ISO 8601 UTC timestamp value. The package also ships MSBuild .props/.targets files to integrate automatically when the NuGet package is referenced.

Supported Frameworks for MSBuild Task

• .NET Standard 2.0 and newer
• .NET Framework 4.7.2 and newer

⭐ Features

• 🕒 Automatic Timestamp: Writes AssemblyMetadata("Blun.Build.Tasks.BuildTimeStamp_UTC", "<ISO8601 UTC timestamp>") at build time
• 📦 Build-Time Generation: Timestamp is captured during the build process, reflecting the actual build artifact creation time
• 🔧 Extension Method: Provides an auto-generated GetBuildTimeStampUtc() extension method for easy runtime access
• 🎯 Zero Configuration: Works automatically once the NuGet package is installed
• ✅ ISO 8601 Format: Timestamps are stored in standardized ISO 8601 UTC format for easy parsing and interoperability

🚀 Installation & Quick Start

Via NuGet Package Manager

Install the NuGet package Blun.Build.Tasks.BuildTimeStamp:

# using the .NET CLI
dotnet add package Blun.Build.Tasks.BuildTimeStamp

Or via NuGet Package Manager in Visual Studio:

Install-Package Blun.Build.Tasks.BuildTimeStamp

Auto-Integration

Once installed, the included build/Blun.Build.Tasks.BuildTimeStamp.props and build/Blun.Build.Tasks.BuildTimeStamp.targets are imported automatically by the SDK-style project system. No additional configuration is required.

Important: PrivateAssets Setting (Recommended)

To prevent this build-only task from being included as a runtime dependency in other projects that reference your project, add PrivateAssets="all" to the package reference:

<ItemGroup>
  <PackageReference Include="Blun.Build.Tasks.BuildTimeStamp" Version="1.0.1" PrivateAssets="all" />
</ItemGroup>

Important: Set parameter for build task! (optional)

<PropertyGroup>
  
  <BlunAccessModifierForGeneratedClass>public</BlunAccessModifierForGeneratedClass>
  
  
  <BlunGeneratedClass>true</BlunGeneratedClass>
</PropertyGroup>

🔧 How It Works

What Happens at Build Time

The MSBuild task automatically generates two C# source files in your project:

1. /opt/**/Blun.Build.Tasks.BuildTimeStamp.generated.cs — Contains the assembly metadata attribute with the build timestamp - prebuild file
2. Blun.Build.Tasks.BuildTimeStamp.generated.cs — Contains an extension method GetBuildTimeStampUtc() for easy runtime access

Assembly Metadata Attribute

The build task injects an AssemblyMetadataAttribute into your assembly:

[assembly: System.Reflection.AssemblyMetadata("Blun.Build.Tasks.BuildTimeStamp_UTC", "2025-01-15T10:30:45.1234567+00:00")]

Example Generated Files

The generated code is similar to:

<ItemGroup>
  <AssemblyAttribute Include="System.Reflection.AssemblyMetadataAttribute">
    <_Parameter1>Blun.Build.Tasks.BuildTimeStamp_UTC</_Parameter1>
    <_Parameter2>$([System.DateTimeOffset]::UtcNow.ToString('o'))</_Parameter2>
  </AssemblyAttribute>
</ItemGroup>

✅ Usage at Runtime

Recommended: Using the Extension Method

The generated Blun.Build.Tasks.BuildTimeStamp.generated.cs file provides an extension method. Simply call it on any assembly:

using System.Reflection;

var buildTimeStamp = typeof(Program).Assembly.GetBuildTimeStampUtc();
if (buildTimeStamp.HasValue)
{
    Console.WriteLine($"Build Time (UTC): {buildTimeStamp:O}");
}
else
{
    Console.WriteLine("No build timestamp found");
}

Alternative: Direct Reflection

If you prefer to access the metadata directly without the extension method:

using System.Reflection;

var assembly = Assembly.GetEntryAssembly() ?? Assembly.GetExecutingAssembly();
var metadataAttributes = assembly.GetCustomAttributes<AssemblyMetadataAttribute>();
var buildTime = metadataAttributes
    .FirstOrDefault(a => a.Key == "Blun.Build.Tasks.BuildTimeStamp_UTC")
    ?.Value;

Console.WriteLine(buildTime ?? "(no build timestamp found)");

Parsing the Timestamp

The timestamp is stored in ISO 8601 format (UTC). Parse it using:

var buildTimeStamp = typeof(Program).Assembly.GetBuildTimeStampUtc();
if (buildTimeStamp.HasValue)
{
    // Already parsed as DateTimeOffset
    DateTime buildDateTime = buildTimeStamp.Value.DateTime;
    Console.WriteLine($"Build Date: {buildDateTime:yyyy-MM-dd}");
    Console.WriteLine($"Build Time: {buildDateTime:HH:mm:ss}");
}

Notes

• The timestamp is in UTC and includes timezone information
• The format is ISO 8601 round-trip format (O), preserving full precision
• Timestamps can be compared, formatted, or serialized without additional parsing

📚 Example Project

The example/Blun.TestBuildApp directory contains a working example that demonstrates:

• ✅ Installing the Blun.Build.Tasks.BuildTimeStamp NuGet package
• ✅ Reading the build timestamp at runtime using the extension method
• ✅ Formatting and displaying the timestamp

Example Output:

Build Time (UTC): 2025-12-06T09:53:28.5041962+00:00
Build Date (local): 2025-12-06
Build Time (local): 10:53:28

See the full example:

• Program.cs
• Blun.TestBuildApp.csproj

🤝 Contributing

Contributions are welcome! Here are some ways you can help:

• 📝 Documentation: Improve guides, fix typos, add examples
• 🧪 Tests: Add new tests, improve test coverage, fix failing tests
• 🐛 Issues: Report bugs or request features via the issue tracker
• 💻 Code: Submit pull requests with improvements

Guidelines

• Follow the existing code style and conventions
• Add or update tests for any behavior changes
• Update documentation as needed
• Use clear commit messages

📄 License

This project is licensed under the MIT License. See the LICENSE file in the repository root for full details.

Author: Björn Lundström (BLun78)
Repository: https://codeberg.org/BLun78/Blun.Build.Tasks.BuildTimeStamp
NuGet Package: https://www.nuget.org/packages/Blun.Build.Tasks.BuildTimeStamp