joeltankam / central-packages-sample

Sample project

This repository is a sample related to NuGet/Home#10578 and NuGet/Home#6764

Description

As described in the issue mentioned above, we have a C# project (ProjectA). This project depends on a project (ProjectB) as well as a package (Package1) that depends on another package (Package2) not mentioned in the project file:

ProjectA <- ProjectB
    ^
    +------ Package1 <- Package2

// (where A <- B means that A depends on B).

We are trying to apply custom metadata to Package1 resolution, say ExcludeAssets=runtime. The status quo is to apply these metadata to all its references, transitively.

Behavior

Using the metadata mentioned above, ExcludeAssets=runtime applied on Package1, we expect Package2 resolution to also exclude runtime assets; Or at least this is currently the case when not using centrally managed package versions.

To showcase this, in the repository Package1 is System.Reflection.Emit.Lightweight and Package2 is System.Reflection.Emit.ILGeneration. When restoring without using centrally managed packages versions, we have the expected and current behavior:

ProjectA.cspoj

<PackageReference Include="System.Reflection.Emit.Lightweight" Version="4.7.0" ExcludeAssets="runtime" />

Command

dotnet restore

project.assets.json (ProjectA)

"System.Reflection.Emit.ILGeneration/4.7.0": {
  "type": "package",
  "compile": {
    "ref/netstandard2.0/System.Reflection.Emit.ILGeneration.dll": {}
  },
  "runtime": {
    "lib/netstandard2.0/_._": {}
  }
},
"System.Reflection.Emit.Lightweight/4.7.0": {
  "type": "package",
  "dependencies": {
    "System.Reflection.Emit.ILGeneration": "4.7.0"
  },
  "compile": {
    "ref/netstandard2.0/System.Reflection.Emit.Lightweight.dll": {}
  },
  "runtime": {
    "lib/netstandard2.0/_._": {}
  }
}

In comparison, the behavior with centrally managed package versions is:

Command

dotnet restore -p:ManagePackageVersionsCentrally=true

project.assets.json (ProjectA)

"System.Reflection.Emit.ILGeneration/4.7.0": {
  "type": "package",
  "compile": {
    "ref/netstandard2.0/System.Reflection.Emit.ILGeneration.dll": {}
  },
  "runtime": {
-   "lib/netstandard2.0/_._": {}
+   "lib/netstandard2.0/System.Reflection.Emit.ILGeneration.dll": {}
  }
},
"System.Reflection.Emit.Lightweight/4.7.0": {
  "type": "package",
  "dependencies": {
    "System.Reflection.Emit.ILGeneration": "4.7.0"
  },
  "compile": {
    "ref/netstandard2.0/System.Reflection.Emit.Lightweight.dll": {}
  },
  "runtime": {
    "lib/netstandard2.0/_._": {}
  }
}

It appears that this is due to the fact that, when using centrally managed package versions, System.Reflection.Emit.Lightweight is wrongly mentioned as a dependency of ProjectB (therefore its dependencies are transitively resolved) even if ProjectB does not depend on any package:

project.assets.json (ProjectA)

"ProjectB/1.0.0": {
  "type": "project",
  "framework": ".NETStandard,Version=v2.0",
+ "dependencies": {
+   "System.Reflection.Emit.Lightweight": "4.7.0"
+ },
  "compile": {
    "bin/placeholder/ProjectB.dll": {}
  },
  "runtime": {
    "bin/placeholder/ProjectB.dll": {}
  }
}