Update to .NET 5 SDK, re-enable .NET Framework (.NET Standard 2.0) support by excluding CreateBootstrapLogger()/ReloadableLogger on that platform

Author: nblumhardt

global.json

@@ -1,7 +1,7 @@
 {
   "sdk": {
     "allowPrerelease": false,
-    "version": "3.1.100",
+    "version": "5.0.102",
     "rollForward": "latestFeature"
   }
 }

src/Serilog.Extensions.Hosting/Extensions/Hosting/CachingReloadableLogger.cs

@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#if !NO_RELOADABLE_LOGGER
+
 using System;
 using System.Collections.Generic;
 using System.Threading;
@@ -516,4 +518,6 @@ public bool BindProperty(string propertyName, object value, bool destructureObje
             return canBind;
         }
     }
-}
+}
+
+#endif

src/Serilog.Extensions.Hosting/Extensions/Hosting/ReloadableLogger.cs

@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#if !NO_RELOADABLE_LOGGER
+
 using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
@@ -667,3 +669,5 @@ internal bool CreateChild(
         }
     }
 }
+
+#endif

src/Serilog.Extensions.Hosting/LoggerConfigurationExtensions.cs

@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#if !NO_RELOADABLE_LOGGER
+
 using Microsoft.Extensions.Hosting;
 using Serilog.Extensions.Hosting;
 using System;
@@ -38,3 +40,5 @@ public static ReloadableLogger CreateBootstrapLogger(this LoggerConfiguration lo
         }
     }
 }
+
+#endif

src/Serilog.Extensions.Hosting/Serilog.Extensions.Hosting.csproj

@@ -2,9 +2,10 @@
 
   <PropertyGroup>
     <Description>Serilog support for .NET Core logging in hosted services</Description>
-    <VersionPrefix>4.0.1</VersionPrefix>
+    <VersionPrefix>4.1.0</VersionPrefix>
     <Authors>Microsoft;Serilog Contributors</Authors>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+    <LangVersion>8</LangVersion>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>Serilog.Extensions.Hosting</AssemblyName>
@@ -22,6 +23,10 @@
     <RootNamespace>Serilog</RootNamespace>
   </PropertyGroup>
 
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
+    <DefineConstants>$(DefineConstants);NO_RELOADABLE_LOGGER</DefineConstants>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Serilog" Version="2.10.0" />
     <PackageReference Include="Serilog.Extensions.Logging" Version="3.0.1" />

src/Serilog.Extensions.Hosting/SerilogHostBuilderExtensions.cs

@@ -125,8 +125,8 @@ public static IHostBuilder UseSerilog(
         /// <param name="writeToProviders">By default, Serilog does not write events to <see cref="ILoggerProvider"/>s registered through
         /// the Microsoft.Extensions.Logging API. Normally, equivalent Serilog sinks are used in place of providers. Specify
         /// <c>true</c> to write events to all providers.</param>
-        /// <remarks>If the static <see cref="Log.Logger"/> is a bootstrap logger (created using
-        /// <see cref="LoggerConfigurationExtensions.CreateBootstrapLogger"/>), and <paramref name="preserveStaticLogger"/> is
+        /// <remarks>If the static <see cref="Log.Logger"/> is a bootstrap logger (see
+        /// <c>LoggerConfigurationExtensions.CreateBootstrapLogger()</c>), and <paramref name="preserveStaticLogger"/> is
         /// not specified, the the bootstrap logger will be reconfigured through the supplied delegate, rather than being
         /// replaced entirely or ignored.</remarks>
         /// <returns>The host builder.</returns>
@@ -140,8 +140,12 @@ public static IHostBuilder UseSerilog(
             if (configureLogger == null) throw new ArgumentNullException(nameof(configureLogger));
 
             // This check is eager; replacing the bootstrap logger after calling this method is not supported.
+#if !NO_RELOADABLE_LOGGER
             var reloadable = Log.Logger as ReloadableLogger;
             var useReload = reloadable != null && !preserveStaticLogger;
+#else
+            const bool useReload = false;
+#endif
 
             builder.ConfigureServices((context, collection) =>
             {
@@ -154,6 +158,7 @@ public static IHostBuilder UseSerilog(
                 collection.AddSingleton(services =>
                 {
                     ILogger logger;
+#if !NO_RELOADABLE_LOGGER
                     if (useReload)
                     {
                         reloadable!.Reload(cfg =>
@@ -168,6 +173,7 @@ public static IHostBuilder UseSerilog(
                         logger = reloadable.Freeze();
                     }
                     else
+#endif
                     {
                         var loggerConfiguration = new LoggerConfiguration();
 

test/Serilog.Extensions.Hosting.Tests/ReloadableLoggerTests.cs

@@ -1,4 +1,6 @@
-using Xunit;
+#if !NO_RELOADABLE_LOGGER
+
+using Xunit;
 
 namespace Serilog.Extensions.Hosting.Tests
 {
@@ -20,3 +22,5 @@ public void AFrozenLoggerYieldsSerilogLoggers()
         }
     }
 }
+
+#endif

test/Serilog.Extensions.Hosting.Tests/Serilog.Extensions.Hosting.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFrameworks>netcoreapp3.1;net5.0;net4.8</TargetFrameworks>
     <AssemblyName>Serilog.Extensions.Hosting.Tests</AssemblyName>
     <AssemblyOriginatorKeyFile>../../assets/Serilog.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
@@ -10,6 +10,10 @@
     <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net4.8' ">
+    <DefineConstants>$(DefineConstants);NO_RELOADABLE_LOGGER</DefineConstants>
+  </PropertyGroup>
+  
   <ItemGroup>
     <ProjectReference Include="..\..\src\Serilog.Extensions.Hosting\Serilog.Extensions.Hosting.csproj" />
   </ItemGroup>