Did you know? – NuGetGallery Build (part 4)

In the last post we left at the point where all previous build output from all projects was deleted. Let’s continue with the build from NuGetGallery.msbuild:

<Target Name="Build" DependsOnTargets="Clean">
    <MSBuild Projects="..\NuGetGallery.sln" Targets="Build" Properties="Configuration=$(Configuration);CodeAnalysis=true;" />
  </Target>

The msbuild task is invoked again, to run the Build target on the NuGetGallery.sln. This file references the “Website\Website.csproj”, MSBuild runs the Build target on this project.

Now, before it can compile anything it needs to download all the dependencies. Notice that NuGetGallery includes very few assemblies as part of the source, take a look at the “3rd Party” folder to see an unimpressive list of references. The trick is that it uses NuGet.exe to download all the extra references before the build. So how does it accomplish this magic? Let’s take a look at WebSite.csproj (simplified):

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build">
  <PropertyGroup>
    <RestorePackages>true</RestorePackages>
  </PropertyGroup>

  <Import Project="$(SolutionDir)\.nuget\NuGet.targets" />
</Project>

Mh, there’s a property called “RestorePackages” that sounds like it’s used to, I don’t know, restoring nuget packages? Remember this one. And at the bottom there is an import of NuGet.targets. That’s where the answers must be!