By default, packing Compile should not include generated files

README.md

@@ -123,6 +123,32 @@ Whether items are packed by default or not is controlled by properties named aft
 \* Back in the day, PDBs were Windows-only and fat files. Nowadays, portable PDBs 
    (the new default) are lightweight and can even be embedded. Combined with [SourceLink](https://github.com/dotnet/sourcelink), including them in the package (either standalone or embeded) provides the best experience for your users, so it's the default.
 
+The various supported item inference are surfaced as `<PackInference Include="Compile;Content;None;..." />` items, which are ultimately evaluated together with the metadata for the individual items. These make the package inference candidates. You can also provide an exclude expression for that evaluation so that certain items are excluded by default, even if every other item of the same type is included. For example, to pack all `Content` items, except those in the `docs` folder, you can simply update the inference item like so:
+
+```xml
+<ItemGroup>
+  <PackInference Update="Content" PackExclude="docs/**/*.*" />
+</ItemGroup>
+```
+
+Of course you could have achieved a similar effect by updating the Content items themselves too instead:
+
+```xml
+<ItemGroup>
+  <Content Update="docs/**/*.*" Pack="false" />
+</ItemGroup>
+```
+
+By default (see [NuGetizer.Inference.props](src/NuGetizer.Tasks/NuGetizer.Inference.props)), `Compile` has the following exclude expression, so generated intermediate compile files aren't packed:
+
+```xml
+<ItemGroup>
+  <PackInference Include="Compile"
+                 PackExclude="$(IntermediateOutputPath)/**/*$(DefaultLanguageSourceExtension)" />
+</ItemGroup>
+```
+
+
 ### CopyToOutputDirectory
 
 There is a common metadata item that's used quite frequently: *CopyToOutputDirectory*, which is typically set to *PreserveNewest* to change it from its default behavior (when empty or set to *Never*).

src/NuGetizer.Tasks/NuGetizer.Inference.props

@@ -0,0 +1,21 @@
+<!--
+***********************************************************************************************
+NuGetizer.Inference.props
+
+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.
+
+Copyright (c) .NET Foundation. All rights reserved. 
+***********************************************************************************************
+-->
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <ItemGroup>
+    <PackInference Include="Compile" PackExclude="$(IntermediateOutputPath)/**/*$(DefaultLanguageSourceExtension)" />
+    <PackInference Include="Content;EmbeddedResource;None;ApplicationDefinition;Page;
+                            Resource;SplashScreen;DesignData;DesignDataWithDesignTimeCreatableTypes;
+                            CodeAnalysisDictionary;AndroidAsset;AndroidResource;BundleResource" />
+  </ItemGroup>
+
+</Project>

src/NuGetizer.Tasks/NuGetizer.Inference.targets

@@ -104,7 +104,10 @@ Copyright (c) .NET Foundation. All rights reserved.
       <Pack Condition="'$(PackBundleResource)' == true">true</Pack>
       <BuildAction>BundleResource</BuildAction>
     </BundleResource>
-
+
+    <PackInference>
+      <PackExclude />
+    </PackInference>
     <InferenceCandidate>
       <DefaultPackFolder />
       <Pack />
@@ -163,16 +166,10 @@ Copyright (c) .NET Foundation. All rights reserved.
                         Pack="false" />
     </ItemGroup>
   </Target>
-
-  <ItemGroup>
-    <PackInference Include="Compile;Content;EmbeddedResource;None;ApplicationDefinition;Page;
-                            Resource;SplashScreen;DesignData;DesignDataWithDesignTimeCreatableTypes;
-                            CodeAnalysisDictionary;AndroidAsset;AndroidResource;BundleResource" />
-  </ItemGroup>
 
   <Target Name="InferPackageContents" DependsOnTargets="$(InferPackageContentsDependsOn)" Returns="@(PackageFile)">
     <ItemGroup>
-      <InferenceCandidate Include="@(%(PackInference.Identity))" />
+      <InferenceCandidate Include="@(%(PackInference.Identity))" Exclude="@(%(PackInference.Identity) -> '%(PackExclude)')"/>
       <InferenceCandidate>
         <ShouldPack Condition="('%(Pack)' == 'true' or '%(PackagePath)' != '' or '%(PackFolder)' != '') and '%(Pack)' != 'false'">true</ShouldPack>
       </InferenceCandidate>

src/NuGetizer.Tasks/NuGetizer.props

@@ -146,6 +146,7 @@ Copyright (c) .NET Foundation. All rights reserved.
   </PropertyGroup>
 
   <Import Project="NuGetizer.Version.props" />
+  <Import Project="NuGetizer.Inference.props" Condition="'$(EnablePackInference)' != 'false'" />
   <Import Project="NuGetizer.Authoring.props" Condition="'$(IsPackagingProject)' == 'true'" />
   <Import Project="dotnet-nugetize.props" Condition="'$(dotnet-nugetize)' != ''"/>
 </Project>

src/NuGetizer.Tests/Builder.NuGetizer.cs

@@ -11,7 +11,6 @@
 using Microsoft.Build.Execution;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Logging.StructuredLogger;
-using NuGet.ProjectManagement;
 using Xunit;
 using Xunit.Abstractions;
 using Xunit.Sdk;
@@ -77,12 +76,12 @@ public static TargetResult BuildProjects(
     }
 
     public static TargetResult BuildScenario(
-    string scenarioName,
-    object properties = null,
-    string projectName = null,
-    string target = "GetPackageContents",
-    ITestOutputHelper output = null,
-    LoggerVerbosity? verbosity = null)
+        string scenarioName,
+        object properties = null,
+        string projectName = null,
+        string target = "GetPackageContents",
+        ITestOutputHelper output = null,
+        LoggerVerbosity? verbosity = null)
     {
         var scenarioDir = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Scenarios", scenarioName);
         if (projectName != null && !Path.HasExtension(projectName))

src/NuGetizer.Tests/Scenarios/Scenario.props

@@ -27,5 +27,9 @@
     <NuGetizerTargets>$(NuGetTargetsPath)\NuGetizer.Shared.targets</NuGetizerTargets>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="$(MSBuildThisFileDirectory)_._" />
+  </ItemGroup>
+
   <Import Project="$(NuGetTargetsPath)\NuGetizer.props" Condition="'$(NuGetizerPropsImported)' != 'true'" />
 </Project>

src/NuGetizer.Tests/Scenarios/Scenario.targets

@@ -8,10 +8,6 @@
     <ScenarioTargetsImported>true</ScenarioTargetsImported>
   </PropertyGroup>
 
-  <ItemGroup>
-    <Compile Include="$(MSBuildThisFileDirectory)_._" />
-  </ItemGroup>
-
   <Target Name="Report" DependsOnTargets="GetPackageContents">
     <Message Importance="high" 
              Text="%(_PackageContent.RelativeDir)%(_PackageContent.Filename)%(_PackageContent.Extension)

src/NuGetizer.Tests/Scenarios/given_a_library/library.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="$([MSBuild]::GetPathOfFileAbove(Scenario.props, $(MSBuildThisFileDirectory)))" />
+  <PropertyGroup>
+		<AssemblyName>library</AssemblyName>
+		<TargetFramework>netstandard2.0</TargetFramework>
+    <IsPackable>true</IsPackable>
+    <EnableDefaultItems>true</EnableDefaultItems>
+    <GenerateAssemblyInfo>true</GenerateAssemblyInfo>
+    <GenerateTargetFrameworkAttribute>true</GenerateTargetFrameworkAttribute>
+  </PropertyGroup>
+  <ItemGroup>
+    <!-- The _._ is added by the scenario targets so that projects aren't entirely empty of compile items -->
+    <Compile Remove="@(Compile -> WithMetadataValue('Extension', '._'))" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(PackOnlyApi)' == 'true'">
+    <PackInference Update="Compile" PackExclude="%(PackExclude);*.cs" />
+  </ItemGroup>
+</Project>

src/NuGetizer.Tests/given_a_library.cs

@@ -0,0 +1,58 @@
+using System.IO;
+using System.Linq;
+using System.ServiceModel.Configuration;
+using Microsoft.Build.Execution;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace NuGetizer
+{
+    public class given_a_library
+    {
+        ITestOutputHelper output;
+
+        public given_a_library(ITestOutputHelper output)
+        {
+            this.output = output;
+            using var disable = OpenBuildLogAttribute.Disable();
+            Builder.BuildScenario(nameof(given_a_library), target: "Restore")
+                .AssertSuccess(output);
+        }
+
+        [Fact]
+        public void when_pack_compile_then_excludes_generated_files()
+        {
+            var result = Builder.BuildScenario(nameof(given_a_library), 
+                new { PackCompile = "true" }, 
+                target: "Build,GetPackageContents,Pack");
+
+            Assert.True(result.BuildResult.HasResultsForTarget("GetPackageContents"));
+
+            var items = result.BuildResult.ResultsByTarget["GetPackageContents"];
+            var compile = items.Items.Where(item => item.Matches(new
+            {
+                BuildAction = "Compile",
+            })).ToArray();
+
+            Assert.Equal(2, compile.Length);
+        }
+
+        [Fact]
+        public void when_pack_excludes_additional_items_then_contains_only_matching_files()
+        {
+            var result = Builder.BuildScenario(nameof(given_a_library),
+                new { PackCompile = "true", PackOnlyApi = "true" },
+                target: "Build,GetPackageContents,Pack");
+
+            Assert.True(result.BuildResult.HasResultsForTarget("GetPackageContents"));
+
+            var items = result.BuildResult.ResultsByTarget["GetPackageContents"];
+            var compile = items.Items.Where(item => item.Matches(new
+            {
+                BuildAction = "Compile",
+            })).ToArray();
+
+            Assert.Single(compile);
+        }
+    }
+}