Looking inside a NuGet package with NuGet Package Explorer

When I really want to learn something new (like a new tool, technology or a programming language) I do two things

• I try it myself
• Check out what others have done

I'm currently learning how to create my own NuGet packages so I'm trying to do a lot of things on my own, but I would also like to see how existing packages are made.

After installing a NuGet package in your project you can go in the packages folder and unzip the .nupkg file (yes, it's only a zip file with a different extension).  Fortunately, there is an easier. NuGet Package Explorer is an open source tool available on CodePlex.

With it you can load a package from the official NuGet feed or any other feeds you want even local feeds.

Then when we open a package we can explore its content and even go inside individual files

NuGet Package Explorer also allow us to edit files and the package itself if we want.

One trick I like to do is to add my local NuGet package download cache as a feed. To do that in the Tools menu select View NuGet download cache.

This is the folder where all the packages you previously downloaded are cached (from Visual Studio, NuGet Package Explorer and any other NuGet based tools). Simply copy the path and paste it in the Package Source field like this

This way I can quickly get to a package I just installed in my solution.

NuGet Package Explorer is a powerful tool I use a lot to understand how NuGet packages are made.

I hope it will help you too.

Packaging and distributing tools using NuGet

NuGet is an amazing tool to manage dependencies for external libraries. As part of Visual Studio it gives us an easy way to install and update those libraries over time. Now even Microsoft use it extensively to release updates to us. But the power of NuGet doesn't stop here. Some people found imaginative ways to use NuGet like the ScriptCs project and Chocolatey.

Another usage is to package and distribute utilities via NuGet packages like FAKE and xUnit.Runners. To create your own tool package you need to author a NuSpec file like this:

<package>
  …

  <files>
    <file src="tooling\app.exe" target="tools\" />
  </files>
</package>

The key here is to set all your file's target to tools\. Doing that the package will be considered a solution-level NuGet package and will be available solution wide instead of only for one project.

For example if I install the xUnit.Runners package to my solution like this:

PM> Install-Package xunit.runners

You will see that only a new package.config file will be created in the .nuget folder at the root of your solution. This is where all solution-level packages will be referenced. Nothing will actually change inside your projects.

After that all the files required to run the xUnit runner from the command line, PowerShell or a build script will be available from the \packages\xunit.runners.1.9.2\tools folder.

The power of NuGet doesn't stop there but we'll check that in another blog post.