feat: add package for enabling IDE0005

README.md

@@ -1,2 +1,25 @@
-# EnableUnnecessaryUsings
-Package that applies a workaround to get IDE0005 (unnecessary usings) in the CLI build
+# SvSoft.MSBuild.CheckUnnecessaryUsings
+
+Enable the compiler check for [unnecessary usings (IDE0005)](https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0005) in CLI builds just by including this package.
+
+```xml
+<PackageReference Include="SvSoft.MSBuild.CheckUnnecessaryUsings" Version="1.0.0" PrivateAssets="all" />
+```
+
+The package will enforce style checking in the build by setting `EnforceCodeStyleInBuild`.
+(You may thus get additional non-IDE0005 style-related warnings, depending on your style settings.)
+It will also set the diagnostic severity of IDE0005 to `warning` for the consuming project via a global analyzer config file.
+The severity will be overridden by default by any `.globalconfig` file or any other global analyzer config file with a `global_level` greater than 10.
+
+# Background
+
+There is a [long standing issue in Roslyn](https://github.com/dotnet/roslyn/issues/41640) that prevents the CLI build from checking for unnecessary usings unless XML doc generation is turned on.
+Yes, I know, crazy.
+There is a [comparatively simple workaround](https://github.com/dotnet/roslyn/issues/41640#issuecomment-985780130).
+But it has some disadvantages:
+
+* causes an unwanted and unnecessary potentially empty XML doc file to be included in the output folder
+* has to be manually disabled as soon as the project _does_ want real XML doc generation
+
+In contrast, this solution does not leave any unnecessary files in the output folder.
+It will also only trigger when `GenerateDocumentationFile` is `false` (default) in the consuming project. As soon as XML doc file generation is enabled by setting it to true, the workaround will no longer trigger and thus not have any unwanted side-effects.

configs/CheckUnnecessaryUsings.globalconfig

@@ -0,0 +1,4 @@
+is_global = true
+global_level = 10
+
+dotnet_diagnostic.IDE0005.severity = warning

configs/CheckUnnecessaryUsings.props

@@ -0,0 +1,8 @@
+<Project>
+    <PropertyGroup>
+        <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
+    </PropertyGroup>
+    <ItemGroup>
+        <GlobalAnalyzerConfigFiles Include="$(MSbuildThisFileDirectory)*.globalconfig" />
+    </ItemGroup>
+</Project>

configs/CheckUnnecessaryUsings.targets

@@ -0,0 +1,15 @@
+<Project>
+    <Target Name="__TriggerUnnecessaryUsingsCheck" BeforeTargets="CoreCompile">
+        <!-- Condition to let consuming projects enable documentation file generation themselves -->
+        <ItemGroup Condition="'$(GenerateDocumentationFile)' != 'true'">
+            <!-- Trigger compiler check for unnecessary usings -->
+            <DocFileItem Include="$(IntermediateOutputPath)DummyDocForUnnecessaryUsings.xml" />
+        </ItemGroup>
+        <PropertyGroup Condition="'$(GenerateDocumentationFile)' != 'true'">
+            <!-- we do not want the dummy file in the output folder -->
+            <CopyDocumentationFileToOutputDirectory>false</CopyDocumentationFileToOutputDirectory>
+            <!-- Disable warnings about missing XML doc comments -->
+            <NoWarn>$(NoWarn);CS1591;CS1573</NoWarn>
+        </PropertyGroup>
+    </Target>
+</Project>

package/CheckUnnecessaryUsings.csproj

@@ -0,0 +1,44 @@
+<Project Sdk="Microsoft.NET.Sdk" DefaultTargets="Pack">
+    <PropertyGroup>
+        <PackageId>SvSoft.MSBuild.CheckUnnecessaryUsings</PackageId>
+        <Title>Enable IDE0005 Unnecessary Usings Check</Title>
+        <Description>Applies a workaround so that consuming projects can have IDE0005 (Unnecessary Usings) checked in their compile-time build. Projects can still choose to enable XML doc file generation without interference from this workaround.</Description>
+        <Authors>Sven Hübner</Authors>
+        <PackageTags>msbuild;ide0005;usings</PackageTags>
+        <PackageLicenseExpression>MIT</PackageLicenseExpression>
+        <PackageReadmeFile>README.md</PackageReadmeFile>
+    </PropertyGroup>
+
+    <!-- Make this a no-code package. Use some bogus TFM to make the SDK happy. -->
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+        <NoBuild>true</NoBuild>
+        <IncludeBuildOutput>false</IncludeBuildOutput>
+        <SuppressDependenciesWhenPacking>true</SuppressDependenciesWhenPacking>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="all" />
+    </ItemGroup>
+    <PropertyGroup>
+        <PublishRepositoryurl>true</PublishRepositoryurl>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <None Include="../configs/*.globalconfig"
+              Pack="true"
+              PackagePath="build" />
+
+        <None Include="../configs/*.props"
+              Pack="true"
+              PackagePath="build/$(PackageId).props" />
+
+        <None Include="../configs/*.targets"
+              Pack="true"
+              PackagePath="build/$(PackageId).targets" />
+
+        <None Include="../README.md"
+              Pack="true"
+              PackagePath="/"/>
+    </ItemGroup>
+</Project>

samples/Directory.Build.props

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+<Project>
+    <ItemGroup>
+        <!-- use latest local temp package version -->
+        <PackageReference Include="SvSoft.MSBuild.CheckUnnecessaryUsings" Version="*-test.*" PrivateAssets="all" />
+    </ItemGroup>
+
+    <PropertyGroup>
+        <__UtcTicks>$([System.DateTimeOffset]::Now.UtcTicks)</__UtcTicks>
+        <!-- create some strictly increasing version number -->
+        <__TempPackageVersion>1.0.0-test.$(__UtcTicks)</__TempPackageVersion>
+        <__TempPackageOutputPath>$(MSBuildThisFileDirectory)../_out</__TempPackageOutputPath>
+    </PropertyGroup>
+
+    <PropertyGroup>
+        <!-- restore from the temp package build output folder -->
+        <RestoreAdditionalProjectSources>$(RestoreAdditionalProjectSources);$(__TempPackageOutputPath)</RestoreAdditionalProjectSources>
+    </PropertyGroup>
+
+    <PropertyGroup>
+        <__PackageProjectPath>$(MSBuildThisFileDirectory)../package/CheckUnnecessaryUsings.csproj</__PackageProjectPath>
+    </PropertyGroup>
+
+    <!-- Build a temp package on every restore. -->
+    <Target Name="__PackTempPackage" BeforeTargets="Restore">
+        <MSBuild Targets="restore" Projects="$(__PackageProjectPath)" />
+        <MSBuild Targets="pack"
+                 Projects="$(__PackageProjectPath)"
+                 Properties="OutputPath=$(__TempPackageOutputPath);Version=$(__TempPackageVersion)" />
+    </Target>
+</Project>

samples/nuget.config

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+<configuration>
+    <packageSources>
+        <clear />
+    </packageSources>
+</configuration>

samples/xml_doc_disabled/Class.cs

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+// unnecessary using to trigger IDE0005
+using System.IO;
+
+class Class {}

samples/xml_doc_disabled/Sample_with_doc_disabled.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+    </PropertyGroup>
+</Project>

samples/xml_doc_enabled/Class.cs

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+// unnecessary using to trigger IDE0005
+using System.IO;
+
+class Class {}

samples/xml_doc_enabled/Sample_with_doc_enabled.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+    </PropertyGroup>
+
+    <PropertyGroup>
+        <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    </PropertyGroup>
+</Project>