joeltankam/restore-cli-sample

Sample project

This repository is a sample related to dotnet/project-system#8381.

Summary

The project.assets.json file is incomplete for a C# project when it transitively depends on another C# project through a C++/CLI project. This problem seems to only occur in Visual Studio 2022 17.3 (tested with Preview 4.0 to 6.0) and not previous versions.

Lets say we have three projects: ProjectA (C#), ProjectB (C++/CLI) and ProjectC (C#); so that ProjectA references ProjectB which references ProjectC:

ProjectA (C#) --(depends on)--> ProjectB (C++/CLI) --> ProjectC (C#)

If the ProjectReference from ProjectB to ProjectC does not contain the metadata Project (e.g. <Project>{e5599aee-f39e-4613-b48d-7824eca526e5}</Project>), MSBuild (through command line) and Visual Studio restore won't behave the same way. Typically, the transitive reference to ProjectC is missing from ProjectA's asset file when performing NuGet restore in Visual Studio:

  (...)
  "targets": {
    ".NETFramework,Version=v4.8": {
      "ProjectB/1.0.0": {
        "type": "project",
-       "dependencies": {
-         "ProjectC": "1.0.0"
-       },
        "compile": {
          "bin/placeholder/ProjectB.dll": {}
        },
        "runtime": {
          "bin/placeholder/ProjectB.dll": {}
        }
      },
-     "ProjectC/1.0.0": {
-       "type": "project",
-       "framework": ".NETFramework,Version=v4.8",
-       "compile": {
-         "bin/placeholder/ProjectC.dll": {}
-       },
-       "runtime": {
-         "bin/placeholder/ProjectC.dll": {}
-       }
-     }
    }
  }
  (...)

Steps to Reproduce

1. Perform a restore on ProjectA using MSBuild and check the contain of .\ProjectA\obj\project.assets.json: msbuild -v:m -t:Restore .\ProjectA\ProjectA.csproj
2. Open the solution in Visual Studio 2022 17.3 Preview, force a restore if needed, and check the content of .\ProjectA\obj\project.assets.json again; you will notice the changes mentioned in the summary

Expected Behavior

MSBuild CLI and Visual Studio should have the same behavior, which means the restore should not be performed when opening the solution in Visual Studio. Package Manage log should be:

All packages are already installed and there is nothing to restore.

Actual Behavior

The restore is performed again in Visual Studio for ProjectA:

Restored (...)\ProjectA\ProjectA.csproj (in 0.9 ms). NuGet package restore finished.

Changing .\ProjectA\obj\project.assets.json as described in the summary; creating incremental compilation issues when switching from command-line to VS (e.g. some projects are unnecessarily re-restored and recompiled).