Directory.Build.targets

<Project>
  <!-- Prove the file is imported -->
  <Target Name="__Diag_DirectoryBuildTargets_Imported" BeforeTargets="Build">
    <Message Importance="High" Text="Directory.Build.targets loaded for $(MSBuildProjectName)" />
  </Target>

  <!-- This target blocks unwanted NuGet package versions across the solution -->
  <Target Name="BlockUnwantedDependencies" AfterTargets="ResolvePackageAssets;ResolveReferences">
    <ItemGroup>
      <!-- Collect as many resolved items as possible to ensure NuGet metadata is present -->
      <_AllResolvedFromPackages Include="@(ReferencePath)" />
      <_AllResolvedFromPackages Include="@(ReferenceCopyLocalPaths)" />
      <_AllResolvedFromPackages Include="@(ResolvedCompileFileDefinitions)" />
      <_AllResolvedFromPackages Include="@(RuntimeCopyLocalItems)" />
      <_AllResolvedFromPackages Include="@(ResolvedFileToPublish)" />

      <!-- Rule: block FluentAssertions >= 8.0.0 -->
      <_Unwanted Include="@(_AllResolvedFromPackages)"
                 Condition="'%(_AllResolvedFromPackages.NuGetPackageId)' == 'FluentAssertions'
                            AND $([MSBuild]::VersionGreaterThanOrEquals('%(_AllResolvedFromPackages.NuGetPackageVersion)', '8.0.0'))" />

    </ItemGroup>

    <!-- Optional: log any detected blocked packages -->
    <Message Importance="High"
             Text="Blocked package detected: %(_Unwanted.NuGetPackageId) v%(_Unwanted.NuGetPackageVersion) in $(MSBuildProjectName)"
             Condition="'@(_Unwanted)' != ''" />

    <!-- Fail the build for each offending item (escape < and > in XML attributes!) -->
    <Error Text="Package %(_Unwanted.NuGetPackageId) v%(_Unwanted.NuGetPackageVersion) is not allowed. Please downgrade (e.g., FluentAssertions &lt; 8.0.0)."
           Condition="'@(_Unwanted)' != ''" />
  </Target>
</Project>