In the packages.config days, references were added directly to the project and everything would get copied to the output and the VSIX by default.

PackageReference is a vastly superior approach, but as soon as you switch over, you’ll notice that all those referenced assemblies from packages are gone from the output VSIX.

Not to worry though, since with a little bit of MSBuild, we can achieve anything we want in a build.

In the VSSDK, the target that determines what items make up the VSIX is called GetVsixSourceItems and it uses a $(GetVsixSourceItemsDependsOn) we can add ourselves to in order to run just before it does its thing:

    <PropertyGroup>
      <GetVsixSourceItemsDependsOn>$(GetVsixSourceItemsDependsOn);IncludeNuGetResolvedAssets</GetVsixSourceItemsDependsOn>
    </PropertyGroup>

And the awesome little thingy we need in IncludeNuGetResolvedAssets is just:

	<Target Name="IncludeNuGetResolvedAssets" DependsOnTargets="ResolveNuGetPackageAssets">
      <ItemGroup>
	  	<VSIXCopyLocalReferenceSourceItem Include="@(ReferenceCopyLocalPaths)"  />
      </ItemGroup>
    </Target>

And voilà, files are back! Note that doing it this way does not interfere with the built-in VSSDK VsixSupression package that makes sure you don’t include assemblies you shouldn’t in your VSIX.

And that’s all there is to it.

Happy extending!