Default PackNone to true in packaging projects

src/NuGetizer.Tasks/NuGetizer.Inference.targets

@@ -42,6 +42,8 @@ Copyright (c) .NET Foundation. All rights reserved.
     <PackFrameworkReferences Condition="'$(PackFrameworkReferences)' == '' and '$(IsPackagingProject)' != 'true' and '$(PackFolder)' == 'lib'">true</PackFrameworkReferences>
     <!-- When PackFolder is build/buildTransitive, we default to packing None since it's most intuitive in that case -->
     <PackNone Condition="'$(PackNone)' == '' and ('$(PackFolder)' == 'build' or '$(PackFolder)' == 'buildTransitive')">true</PackNone>
+    <!-- When in a packaging project, default to packing None since it's most intuitive for authoring/packaging projects -->
+    <PackNone Condition="'$(PackNone)' == '' and '$(IsPackagingProject)' == 'true'">true</PackNone>
 
     <_OutputFullPath Condition="$([System.IO.Path]::IsPathRooted($(OutputPath)))">$(OutputPath)</_OutputFullPath>
     <_OutputFullPath Condition="'$(_OutputFullPath)' == ''">$(MSBuildProjectDirectory.TrimEnd('\'))\$(OutputPath)</_OutputFullPath>
@@ -236,6 +238,28 @@ Copyright (c) .NET Foundation. All rights reserved.
     </ItemGroup>
   </Target>
 
+  <!-- 
+    When PackReadme=false, explicitly exclude the readme file from being packed as a None item.
+    This is necessary because PackNone=true in packaging projects would otherwise include it.
+  -->
+  <Target Name="_ExcludeReadmeWhenPackReadmeFalse" 
+          BeforeTargets="_CollectInferenceCandidates"
+          Condition="'$(PackReadme)' == 'false'">
+    <PropertyGroup>
+      <!-- Compute the readme filename, defaulting to readme.md if not specified -->
+      <_PackageReadmeFilename Condition="'$(PackageReadmeFile)' != ''">$(PackageReadmeFile)</_PackageReadmeFilename>
+      <_PackageReadmeFilename Condition="'$(PackageReadmeFile)' == ''">readme.md</_PackageReadmeFilename>
+    </PropertyGroup>
+    <ItemGroup>
+      <None Update="@(None)"
+            Pack="false"
+            Condition="%(None.Identity) == '$(_PackageReadmeFilename)'" />
+      <Content Update="@(Content)"
+               Pack="false"
+               Condition="%(Content.Identity) == '$(_PackageReadmeFilename)'" />
+    </ItemGroup>
+  </Target>
+
   <Target Name="_CollectInferenceCandidates" Inputs="@(PackInference)" Outputs="|%(PackInference.Identity)|">
     <PropertyGroup>
       <PackExclude>%(PackInference.PackExclude)</PackExclude>

src/NuGetizer.Tests/given_a_packaging_project.cs

@@ -499,5 +499,62 @@ public void when_readme_custom_extension_specified_then_adds_metadata_and_conten
                 Readme = "readme.txt",
             }));
         }
+
+        [Fact]
+        public void when_packaging_project_then_none_items_pack_by_default()
+        {
+            var result = Builder.BuildProject(@"
+<Project Sdk='Microsoft.Build.NoTargets/3.7.0'>
+  <PropertyGroup>
+    <PackageId>Packer</PackageId>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <!-- Only needed since for scenarios we set this to false. -->
+    <EnableDefaultItems>true</EnableDefaultItems>
+  </PropertyGroup>
+</Project>",
+                "GetPackageContents", output,
+                files: ("Packer.targets", @"<Project />"));
+
+            result.AssertSuccess(output);
+            Assert.Contains(result.Items, item => item.Matches(new
+            {
+                Filename = "Packer",
+                Extension = ".targets",
+                PackFolder = "None",
+            }));
+        }
+
+        [Fact]
+        public void when_packaging_project_with_none_item_then_packs_without_explicit_packnone()
+        {
+            var result = Builder.BuildProject(@"
+<Project Sdk='Microsoft.Build.NoTargets/3.7.0'>
+  <PropertyGroup>
+    <PackageId>MyPackage</PackageId>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+  <ItemGroup>
+    <None Include='MyPackage.targets' />
+    <None Include='tools\install.ps1' />
+  </ItemGroup>
+</Project>",
+                "GetPackageContents", output,
+                files: [
+                    ("MyPackage.targets", @"<Project />"),
+                    ("tools\\install.ps1", @"# Install script")
+                ]);
+
+            result.AssertSuccess(output);
+            Assert.Contains(result.Items, item => item.Matches(new
+            {
+                Filename = "MyPackage",
+                Extension = ".targets",
+            }));
+            Assert.Contains(result.Items, item => item.Matches(new
+            {
+                Filename = "install",
+                Extension = ".ps1",
+            }));
+        }
     }
 }