Transitive references in .Net Core 1.1

Question

While developing a sample web app in .NET Core 1.1 and Visual Studio 2017 RC, I realized the following:

As you can see:

• ClassLibrary3 has a reference to ClassLibrary2,
• and ClassLibrary2 has a reference to ClassLibrary1

I wrote a simple method in class Class3 of ClassLibrary3 project, and the Intellisense allowed me to use Class1 just writing the name of the class, I mean, without doing an explicit reference to ClassLibrary1 project.

Am I missing some point here? I don't want somebody simply comes and overlooks ClassLibrary2.

Thanks.

Answer 1

Transitive project-to-project references are a new feature of Visual Studio 2017 and Microsoft.NET.Sdk. This is intentional behavior.

See https://github.com/dotnet/sdk/issues/200.

Answer 2

If you're interested in disabling the transitive reference behavior, I finally found a way.

If you want Project A to reference B and B to reference C, but don't want A to reference C, you can add PrivateAssets="All" to B's ProjectReference to C, like so:

In B.csproj

<ItemGroup>
  <ProjectReference Include="..\C\C.csproj" PrivateAssets="All" />
</ItemGroup>

This setting makes C's reference private so it only exists within B. Now projects that reference B will no longer also reference C.

Source: https://github.com/dotnet/project-system/issues/2313