fix api compatibility

Author: suraciii

Directory.Build.props

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <LangVersion>12</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <ImplicitUsings>enable</ImplicitUsings>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <Nullable>enable</Nullable>

Directory.Packages.props

@@ -17,7 +17,6 @@
     <PackageVersion Include="OpenTelemetry.Exporter.InMemory" Version="$(OtelVersion)" />
     <PackageVersion Include="OpenTelemetry.Exporter.Console" Version="$(OtelVersion)" />
     <PackageVersion Include="OpenTelemetry.Extensions.Hosting" Version="$(OtelVersion)" />
-    <PackageVersion Include="PolySharp" Version="1.14.1" />
     <PackageVersion Include="System.Diagnostics.DiagnosticSource" Version="[7.0.2,)" />
     <PackageVersion Include="System.Threading.Channels" Version="[7.0.0,)" />
     <PackageVersion Include="System.Threading.Tasks.Extensions" Version="[4.5.4,)" />

src/DCA.Extensions.BackgroundTask.MediatR/CompatibilitySuppressions.xml

@@ -3,7 +3,19 @@
 <Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
-    <Target>T:System.Runtime.CompilerServices.IsExternalInit</Target>
+    <Target>T:System.Diagnostics.CodeAnalysis.SetsRequiredMembersAttribute</Target>
+    <Left>lib/net6.0/DCA.Extensions.BackgroundTask.dll</Left>
+    <Right>lib/net7.0/DCA.Extensions.BackgroundTask.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:System.Runtime.CompilerServices.CompilerFeatureRequiredAttribute</Target>
+    <Left>lib/net6.0/DCA.Extensions.BackgroundTask.dll</Left>
+    <Right>lib/net7.0/DCA.Extensions.BackgroundTask.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:System.Runtime.CompilerServices.RequiredMemberAttribute</Target>
     <Left>lib/net6.0/DCA.Extensions.BackgroundTask.dll</Left>
     <Right>lib/net7.0/DCA.Extensions.BackgroundTask.dll</Right>
   </Suppression>

src/DCA.Extensions.BackgroundTask/CompatibilitySuppressions.xml

@@ -0,0 +1,34 @@
+#if NET5_0_OR_GREATER
+// context: https://github.com/StackExchange/StackExchange.Redis/issues/2619
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.IsExternalInit))]
+#else
+// To support { get; init; } properties
+using System.ComponentModel;
+
+namespace System.Runtime.CompilerServices
+{
+    [EditorBrowsable(EditorBrowsableState.Never)]
+    internal static class IsExternalInit { }
+}
+#endif
+
+#if !NET7_0_OR_GREATER
+namespace System.Runtime.CompilerServices
+{
+#pragma warning disable CA1018 // Mark attributes with AttributeUsageAttribute
+    public class RequiredMemberAttribute : Attribute { }
+    public class CompilerFeatureRequiredAttribute : Attribute
+	{
+#pragma warning disable IDE0290 // Use primary constructor
+        public CompilerFeatureRequiredAttribute(string name) { }
+    }
+}
+
+namespace System.Diagnostics.CodeAnalysis
+{
+	[AttributeUsage(AttributeTargets.Constructor, AllowMultiple = false, Inherited = false)]
+	public sealed class SetsRequiredMembersAttribute : Attribute
+	{
+	}
+}
+#endif

src/DCA.Extensions.BackgroundTask/Hacks.cs

@@ -42,11 +42,4 @@
     <None Include="$(RepositoryRoot)\LICENSE" Pack="true" PackagePath=""/>
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)'=='net6.0'">
-    <PackageReference Include="PolySharp">
-      <PrivateAssets>all</PrivateAssets>
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-    </PackageReference>
-  </ItemGroup>
-
 </Project>