Target .NET6 instead of .NET Standard 2.0 and .NET Core 3.1 (#280)

* Set Target Framework to net6.0, remove conditional compilations and fix variety of arising nullability errors

* Fix typos

* Use static where possible for private methods

* Fix typo in internal class name

* Improve style consistency in xml doc comments

* Simplify control flow

* Use Contains over IndexOf >= 0

* Modernize code style and adjust indentation for consistency

* Use discard over __

* Remove redundant annotations

Author: Mafii

src/Kestrel.Certificates/KestrelHttpsOptionsExtensions.cs

@@ -8,7 +8,7 @@
 namespace Microsoft.AspNetCore.Hosting;
 
 /// <summary>
-/// API for configuring Kestrel certificiate options
+/// API for configuring Kestrel certificate options
 /// </summary>
 public static class KestrelHttpsOptionsExtensions
 {
@@ -22,7 +22,7 @@ public static HttpsConnectionAdapterOptions UseServerCertificateSelector(
         this HttpsConnectionAdapterOptions httpsOptions,
         IServerCertificateSelector certificateSelector)
     {
-        httpsOptions.ServerCertificateSelector = certificateSelector.Select;
+        httpsOptions.ServerCertificateSelector = certificateSelector.Select!;
         return httpsOptions;
     }
 }

src/Kestrel.Certificates/McMaster.AspNetCore.Kestrel.Certificates.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1;netstandard2.0</TargetFrameworks>
+    <TargetFramework>net6.0</TargetFramework>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Nullable>enable</Nullable>
     <IsPackable>true</IsPackable>
@@ -13,12 +13,9 @@ This library includes API for dynamically selecting which HTTPS certificate to u
     <PackageVersion Condition="'$(IncludePreReleaseLabelInPackageVersion)' == 'true'">$(PackageVersion)-$(VersionSuffix)</PackageVersion>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
+  <ItemGroup>
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
-    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel.Core" Version="2.1.25" />
-  </ItemGroup>
 
 </Project>

src/LettuceEncrypt.Azure/AzureKeyVaultLettuceEncryptOptions.cs

@@ -1,9 +1,7 @@
 // Copyright (c) Nate McMaster.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if FEATURE_VALIDATE_DATA_ANNOTATIONS
 using System.ComponentModel.DataAnnotations;
-#endif
 using Azure.Core;
 using Azure.Identity;
 using LettuceEncrypt.Accounts;
@@ -18,10 +16,8 @@ public class AzureKeyVaultLettuceEncryptOptions
     /// <summary>
     /// Gets or sets the Url for the KeyVault instance.
     /// </summary>
-#if FEATURE_VALIDATE_DATA_ANNOTATIONS
     [Url]
     [Required]
-#endif
     public string AzureKeyVaultEndpoint { get; set; } = null!;
 
     /// <summary>
@@ -34,8 +30,6 @@ public class AzureKeyVaultLettuceEncryptOptions
     /// This is a JSON string which encodes the information in <see cref="AccountModel"/>.
     /// If not set, the name defaults to the name of the "le-account-${ACME server hostname}".
     /// </summary>
-#if FEATURE_VALIDATE_DATA_ANNOTATIONS
     [MaxLength(127)]
-#endif
     public string? AccountKeySecretName { get; set; }
 }

src/LettuceEncrypt.Azure/AzureLettuceEncryptExtensions.cs

@@ -57,13 +57,10 @@ public static ILettuceEncryptServiceBuilder PersistCertificatesToAzureKeyVault(
                 config?.Bind("LettuceEncrypt:AzureKeyVault", o));
         });
 
-        var options = services
+        services
             .AddOptions<AzureKeyVaultLettuceEncryptOptions>()
-            .Configure(configure);
-
-#if FEATURE_VALIDATE_DATA_ANNOTATIONS
-        options.ValidateDataAnnotations();
-#endif
+            .Configure(configure)
+            .ValidateDataAnnotations();
 
         return builder;
     }

src/LettuceEncrypt.Azure/LettuceEncrypt.Azure.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1;netstandard2.0</TargetFrameworks>
+    <TargetFramework>net6.0</TargetFramework>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Nullable>enable</Nullable>
     <IsPackable>true</IsPackable>
@@ -12,10 +12,6 @@ See https://nuget.org/packages/LettuceEncrypt for more details.
     </PackageDescription>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.1' ">
-    <DefineConstants>$(DefineConstants);FEATURE_VALIDATE_DATA_ANNOTATIONS</DefineConstants>
-  </PropertyGroup>
-
   <ItemGroup>
     <PackageReference Include="Azure.Identity" Version="1.6.0" />
     <PackageReference Include="Azure.Security.KeyVault.Certificates" Version="4.3.0" />

src/LettuceEncrypt/FileSystemPersistenceExtensions.cs

@@ -22,7 +22,7 @@ public static class FileSystemStorageExtensions
     /// </summary>
     /// <param name="builder"></param>
     /// <param name="directory">The root directory for storing information. Information may be stored in subdirectories.</param>
-    /// <param name="pfxPassword">Set to null or empty for passwordless .pfx files.</param>
+    /// <param name="pfxPassword">Set to null or empty for password-less .pfx files.</param>
     /// <returns></returns>
     public static ILettuceEncryptServiceBuilder PersistDataToDirectory(
         this ILettuceEncryptServiceBuilder builder,
@@ -47,7 +47,7 @@ public static ILettuceEncryptServiceBuilder PersistDataToDirectory(
 
         foreach (var serviceDescriptor in otherFileSystemRepoServices)
         {
-            var otherRepo = (FileSystemCertificateRepository)serviceDescriptor.ImplementationInstance;
+            var otherRepo = (FileSystemCertificateRepository)serviceDescriptor.ImplementationInstance!;
             if (otherRepo.RootDir.Equals(directory))
             {
                 if (otherRepo.PfxPassword != pfxPassword)

src/LettuceEncrypt/ICertificateRepository.cs

@@ -13,7 +13,7 @@ public interface ICertificateRepository
     /// <summary>
     /// Save the certificate.
     /// </summary>
-    /// <param name="certificate">The certificate, including its private keys</param>
+    /// <param name="certificate">The certificate, including its private keys.</param>
     /// <param name="cancellationToken">A token which, when canceled, should stop any async operations.</param>
     /// <returns>A task which completes once the certificate is done saving.</returns>
     Task SaveAsync(X509Certificate2 certificate, CancellationToken cancellationToken);

src/LettuceEncrypt/ICertificateSource.cs

@@ -14,6 +14,6 @@ public interface ICertificateSource
     /// Gets available certificates from the source.
     /// </summary>
     /// <param name="cancellationToken">A cancellation token.</param>
-    /// <returns>A collection of certificates</returns>
+    /// <returns>A collection of certificates.</returns>
     Task<IEnumerable<X509Certificate2>> GetCertificatesAsync(CancellationToken cancellationToken);
 }

src/LettuceEncrypt/Internal/AcmeCertificateFactory.cs

@@ -12,10 +12,6 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
-#if NETSTANDARD2_0
-using IHostApplicationLifetime = Microsoft.Extensions.Hosting.IApplicationLifetime;
-#endif
-
 namespace LettuceEncrypt.Internal;
 
 internal class AcmeCertificateFactory

src/LettuceEncrypt/Internal/AcmeCertificateLoader.cs

@@ -91,8 +91,6 @@ protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     }
 
     private bool LettuceEncryptDomainNamesWereConfigured()
-    {
-        return _options.Value.DomainNames
+        => _options.Value.DomainNames
             .Any(w => !string.Equals("localhost", w, StringComparison.OrdinalIgnoreCase));
-    }
 }