Update PesterTests and devcontainer to .NET 8

.devcontainer/devcontainer.json

@@ -1,24 +1,25 @@
-// For format details, see https://aka.ms/vscode-remote/devcontainer.json or this file's README at:
-// https://github.com/microsoft/vscode-dev-containers/tree/v0.209.5/containers/dotnet
+// For format details, see https://aka.ms/vscode-remote/devcontainer.json
 {
 	"name": "Pester",
-	"build": {
-		"dockerfile": "Dockerfile",
-		"args": {
-			// Update 'VARIANT' to pick a .NET Core version: 3.1, 5.0, 6.0
-			// Append -bullseye or -focal to pin to an OS version. Using focal (Ubuntu) for pwsh support
-			"VARIANT": "6.0-focal"
+	"image": "mcr.microsoft.com/devcontainers/dotnet:1-8.0-jammy",
+	"remoteUser": "vscode",
+	"customizations": {
+		"codespaces": {
+			"openFiles": [
+				"CONTRIBUTING.md"
+			]
+		},
+		"vscode": {
+			"settings": {},
+			"extensions": [
+				"ms-vscode.powershell",
+				"ms-dotnettools.csharp",
+				"redhat.vscode-xml",
+				"ms-azure-devops.azure-pipelines",
+				"GitHub.vscode-github-actions"
+			]
 		}
 	},
-	// Set *default* container specific settings.json values on container create.
-	"settings": {},
-	// Add the IDs of extensions you want installed when the container is created.
-	"extensions": [
-		"ms-vscode.powershell",
-		"ms-dotnettools.csharp",
-		"redhat.vscode-xml"
-	],
-	// Use 'postCreateCommand' to run commands after the container is created.
 	// Restoring the c# projects
 	"postCreateCommand": "dotnet restore src/csharp"
 }

CONTRIBUTING.md

@@ -8,7 +8,7 @@ for more information.
 
 ## Building Pester
 
-Pester is written in Powershell and C#. The C# solution requires .Net
+Pester is written in Powershell and C#. The C# solution requires .NET
 Framework SDKs and Developer Packs in order to compile, see links below
 how to install those prior to building.
 

src/csharp/Pester/Pester.csproj

@@ -10,7 +10,7 @@
   <!-- PowerShell 7.2.x is the oldest supported PowerShell version. That version is built using net6.0.
   But there is a bug in 7.2.0 reference assemblies, up to 7.2.10, where the IExtens.File is missing from the reference assembly:
   https://github.com/PowerShell/PowerShell/issues/16408
-  
+
   So we use the version released before 7.2.0 which was 7.1.7. We could probably use 7.2.10 safely as well,
   -->
   <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">

src/csharp/PesterTests/PesterTests.csproj

@@ -1,17 +1,20 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <LangVersion>latest</LangVersion>
     <IsPackable>false</IsPackable>
     <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
+    <!-- Workaround for NETSDK1206 warning about version-specific RIDs in
+    Microsoft.Management.Infrastructure dependency. Resolved in PowerShell 7.4 SDK -->
+    <UseRidGraph>true</UseRidGraph>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
-    <PackageReference Include="xunit" Version="2.4.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" />
-    <PackageReference Include="coverlet.collector" Version="3.1.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="xunit" Version="2.7.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7" />
+    <PackageReference Include="coverlet.collector" Version="6.0.2" />
   </ItemGroup>
 
   <ItemGroup>