Update a NuGet package with MSBuild

In this post I’ll show you how to add a prebuild MSBuild target to your project that updates a NuGet package in the project when you rebuild.

Background

We ship a zip file of BreezeJs samples . Some (soon to be all) of them rely on a NuGet package to supply the Breeze JavaScript files and other dependencies.

Breeze changes regularly (for the better we think) and so must the NuGet package version.

Our sample solutions are set to restore all NuGet packages so that we don’t have to ship them as part of the zip. Unfortunately, the “packages.config” file that identifies the BreezeJs NuGet package is stuck with the old version. Package restore simply grabs the old version of that package.

We could not find a way to markup the items in the packages.config so that NuGet restored the latest version of the package. It always restores the exact version identified in package.config.

We don’t want to modify those samples every time we update the NuGet package. We want the samples to update to the latest BreezeJs automatically.

We don’t want to update every package in the solution; just our BreezeJs package and its dependencies.

Solution

We added a prebuild target to the bottom of the project file. The target invokes nuget.exe from the command line, telling it to update only our package (“Breeze.MVC4WebApi”) and its dependencies.

We know that nuget.exe is in the project sibling “.nuget” directory because that’s where the package restore facility puts it.

Here’s our target:

<Target Name="BeforeBuild">
  <Exec Command="&quot;$(SolutionDir).nuget\NuGet&quot; update &quot;$(ProjectDir)packages.config&quot; -Id Breeze.MVC4WebApi" />
</Target>