Trim with Squash

Unreachable IL is removed from DiffEngine at build time. It honors
InternalsVisibleTo, since DiffEngineTray, the benchmarks and the tests use its
internals. Version 20.7.1.

Author: SimonCropp

src/DiffEngine/DiffEngine.csproj

@@ -4,6 +4,8 @@
     <!-- The .NET Framework legs, which only Windows can build -->
     <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT'">net462;net472;net48;$(TargetFrameworks)</TargetFrameworks>
     <AllowUnsafeBlocks Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">true</AllowUnsafeBlocks>
+    <!-- DiffEngineTray, the benchmarks and the tests use internals through InternalsVisibleTo -->
+    <SquashInternalsVisibleTo>Honor</SquashInternalsVisibleTo>
     <IsAotCompatible Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">true</IsAotCompatible>
   </PropertyGroup>
   <ItemGroup>
@@ -21,6 +23,7 @@
     <PackageReference Include="EmptyFiles" PrivateAssets="None" />
     <PackageReference Include="Polyfill" PrivateAssets="all" />
     <PackageReference Include="ProjectDefaults" PrivateAssets="all" />
+    <PackageReference Include="Squash" PrivateAssets="all" />
     <None Include="buildTransitive\DiffEngine.targets" Pack="true" PackagePath="buildTransitive\" />
   </ItemGroup>
 

src/Directory.Build.props

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
   <PropertyGroup>
-    <Version>20.7.0</Version>
+    <Version>20.7.1</Version>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>Testing, Snapshot, Diff, Compare</PackageTags>
     <Description>Launches diff tools based on file extensions. Designed to be consumed by snapshot testing libraries.</Description>
@@ -17,8 +17,11 @@
     One NoWarn, because a second property of the same name replaces the first rather than adding to
     it. There were two, so CS0649, NU1608 and NU1109 were not suppressed at all - and with
     TreatWarningsAsErrors below they would have failed a build rather than warned in one.
+
+    IL2070 is a linker warning from Squash, for reflection inside Polyfill that is kept on .NET
+    Framework because DiffEngine honors InternalsVisibleTo.
     -->
-    <NoWarn>CS1591;CS0649;NU1608;NU1109;CA1416</NoWarn>
+    <NoWarn>CS1591;CS0649;NU1608;NU1109;CA1416;IL2070</NoWarn>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
     <SuppressNETCoreSdkPreviewMessage>true</SuppressNETCoreSdkPreviewMessage>

src/Directory.Packages.props

@@ -21,6 +21,7 @@
     <PackageVersion Include="SkiaSharp.NativeAssets.Linux.NoDependencies" Version="4.153.1" />
     <PackageVersion Include="Polyfill" Version="11.4.3" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.184" />
+    <PackageVersion Include="Squash" Version="0.1.0-beta.2" />
     <PackageVersion Include="Sbom" Version="0.3.1" />
     <PackageVersion Include="Serilog" Version="4.4.0" />
     <PackageVersion Include="Serilog.Sinks.File" Version="7.0.0" />