Add compatibility with SDK package validation

readme.md

@@ -554,6 +554,23 @@ This option is useful in combination with `BuildProjectReferences=false` when
 packing on CI, since at that point all that's run are the P2P protocol involving 
 `GetPackageContents`.
 
+### Package Validation
+
+[Package validation](https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/overview) 
+is a new feature in .NET 6 that allows you to validate that your multi-targeting 
+library packages offer consistent APIs across all targets. Since it's quite 
+important to validate that your packages are consistent across all targets, 
+NuGetizer turns this feature on by default for `Release` builds in multi-targeting 
+projects (unlike the default which is strictly opt-in).
+
+You can turn this off by setting the following property at the project level:
+
+```xml
+<PropertyGroup>
+  <EnablePackageValidation>false</EnablePackageValidation>
+</PropertyGroup>
+```
+
 <!-- include https://github.com/devlooped/sponsors/raw/main/footer.md -->
 # Sponsors 
 

src/NuGetizer.Tasks/NuGetizer.PackageValidation.targets

@@ -0,0 +1,60 @@
+<!--
+***********************************************************************************************
+NuGetizer.PackageValidation.targets
+
+WARNING:  DO NOT MODIFY this file unless you are knowledgeable about MSBuild and have
+          created a backup copy.  Incorrect changes to this file will make it
+          impossible to load or build your projects from the command-line or the IDE.
+
+This targets file adds compatibility with the .NET SDK package validation feature 
+(see https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/overview).
+***********************************************************************************************
+-->
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <PropertyGroup Condition="$(NuGetPackTaskAssemblyFile) == ''">
+    <NuGetPackTaskAssemblyFile Condition="'$(MSBuildRuntimeType)' == 'Core'">$(MSBuildSDKsPath)\NuGet.Build.Tasks.Pack\CoreCLR\NuGet.Build.Tasks.Pack.dll</NuGetPackTaskAssemblyFile>
+    <NuGetPackTaskAssemblyFile Condition="'$(MSBuildRuntimeType)' != 'Core'">$(MSBuildSDKsPath)\NuGet.Build.Tasks.Pack\Desktop\NuGet.Build.Tasks.Pack.dll</NuGetPackTaskAssemblyFile>
+  </PropertyGroup>
+
+  <UsingTask Condition="$(UsingMicrosoftNETSdk) == 'true' and Exists($(NuGetPackTaskAssemblyFile))"
+             TaskName="NuGet.Build.Tasks.GetProjectTargetFrameworksTask" AssemblyFile="$(NuGetPackTaskAssemblyFile)" />
+
+  <Target Name="AfterGetPackageContents" BeforeTargets="Pack" DependsOnTargets="GetPackageContents;GetPackageTargetPath">
+    <ItemGroup>
+      <_NuGetPackInput Include="@(_PackageContent -> WithMetadataValue('PackFolder', 'lib'));
+                                @(_PackageContent -> WithMetadataValue('PackageFolder', 'lib'))" />
+      <NuGetPackInput Include="@(_PackageContent -> Distinct())" />
+    </ItemGroup>
+  </Target>
+
+  <!--
+    ============================================================
+    _GetTargetFrameworksOutput
+    Read target frameworks from the project.
+    Cloned for compatibility from NuGet.Build.Tasks.Pack SDK.
+    ============================================================
+  -->
+  <Target Name="_GetTargetFrameworksOutput" Returns="@(_TargetFrameworks)">
+
+    <PropertyGroup>
+      <_ProjectFrameworks/>
+    </PropertyGroup>
+
+    <GetProjectTargetFrameworksTask ProjectPath="$(MSBuildProjectFullPath)"
+                                    TargetFrameworks="$(TargetFrameworks)"
+                                    TargetFramework="$(TargetFramework)"
+                                    TargetFrameworkMoniker="$(TargetFrameworkMoniker)"
+                                    TargetPlatformIdentifier="$(TargetPlatformIdentifier)"
+                                    TargetPlatformVersion="$(TargetPlatformVersion)"
+                                    TargetPlatformMinVersion="$(TargetPlatformMinVersion)">
+      <Output TaskParameter="ProjectTargetFrameworks"
+              PropertyName="_ProjectFrameworks" />
+    </GetProjectTargetFrameworksTask>
+
+    <ItemGroup Condition=" '$(_ProjectFrameworks)' != '' ">
+      <_TargetFrameworks Include="$(_ProjectFrameworks.Split(';'))" />
+    </ItemGroup>
+  </Target>
+
+</Project>

src/NuGetizer.Tasks/NuGetizer.Shared.targets

@@ -40,6 +40,9 @@ Copyright (c) .NET Foundation. All rights reserved.
     <EmitNuspec Condition="'$(EmitNuspec)' == ''">false</EmitNuspec>
     <NuspecFile Condition="'$(NuspecFile)' == '' and '$(PackageId)' != ''">$(BaseOutputPath.TrimEnd('\'))\$(PackageId).nuspec</NuspecFile>
     <NuspecFile Condition="'$(NuspecFile)' == '' and '$(PackageId)' == ''">$(BaseOutputPath.TrimEnd('\'))\$(AssemblyName).nuspec</NuspecFile>
+
+    <!-- We default package validation to true for Release multi-targeting projects, ensuring best-practices. It's opt-in in .NET6+ otherwise. -->
+    <EnablePackageValidation Condition="$(EnablePackageValidation) == '' and $(Configuration) == 'Release' and '$(TargetFrameworks)' != ''">true</EnablePackageValidation>
   </PropertyGroup>
 
   <PropertyGroup Label="Hidden">
@@ -291,5 +294,10 @@ Copyright (c) .NET Foundation. All rights reserved.
 
   <!-- Cleanups improve the local development loop, by always ensure the fresly built packages can be restored from output -->
   <Import Project="NuGetizer.Cleanup.targets" Condition="'$(CI)' != 'true' and '$(EnablePackCleanup)' != 'false' and '$(IsPackable)' == 'true' and '$(PackageId)' != ''" />
+
+  <!-- In NuGetizer.props, we point the pack targets to our metadata one, so it's imported last automatically, from the Sdk.targets. 
+       So we only need to import again here if *not* using the UsingMicrosoftNETSdk -->
   <Import Project="NuGetizer.PackageMetadata.targets" Condition="'$(NuGetizerPackageMetadataImported)' != 'true' and '$(UsingMicrosoftNETSdk)' != 'true'" />
+
+  <Import Project="NuGetizer.PackageValidation.targets" Condition="$(EnablePackageValidation) == 'true'" />
 </Project>

src/NuGetizer.Tasks/readme.md

@@ -18,7 +18,7 @@ Comprehensive and intuitive heuristics built from experience building nuget pack
 * SourceLink support to populate [repository information in the package](https://devblogs.microsoft.com/nuget/introducing-source-code-link-for-nuget-packages/)
 * Automatic `readme.md` inclusion in the package
 * Support for [content includes in readme](https://www.cazzulino.com/pack-readme-includes.html)
-
+* [Package validation](https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/overview) enabled by default for release multi-targeting packages.
 
 It's strongly recommended that you install the [dotnet-nugetize](https://nuget.org/packages/dotnet-nugetize) tool to get the best experience with NuGetizer:
 

src/NuGetizer.Tests/InlineProjectTests.cs

@@ -800,5 +800,22 @@ public void when_private_assets_then_packs_transitively()
                 PackFolder = "Lib",
             }));
         }
+
+        [Fact]
+        public void when_validating_package_then_succeeds()
+        {
+            var result = Builder.BuildProject(
+                """
+                <Project Sdk="Microsoft.NET.Sdk">
+                	<PropertyGroup>
+                		<TargetFrameworks>net6.0;net7.0</TargetFrameworks>
+                        <IsPackable>true</IsPackable>
+                        <EnablePackageValidation>true</EnablePackageValidation>
+                	</PropertyGroup>                
+                </Project>
+                """, target: "Pack", output: output);
+
+            result.AssertSuccess(output);
+        }
     }
 }