Upgrading 'Hello World' sample

samples/HelloWorld/HelloGrain.cs

@@ -1,10 +1,7 @@
-using System.Threading.Tasks;
-using Orleans;
+namespace HelloWorld;
 
-namespace HelloWorld
+public sealed class HelloGrain : Grain, IHelloGrain
 {
-    public class HelloGrain : Grain, IHelloGrain
-    {
-        public Task<string> SayHello(string greeting) => Task.FromResult($"Hello, {greeting}!");
-    }
+    public ValueTask<string> SayHello(string greeting) =>
+        ValueTask.FromResult($"Hello, {greeting}!");
 }

samples/HelloWorld/HelloWorld.csproj

@@ -1,17 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net7.0</TargetFramework>
     <OutputType>Exe</OutputType>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.0" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="6.0.0" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="6.0.0" />
-    <PackageReference Include="Microsoft.Orleans.Core" Version="3.6.2" />
-    <PackageReference Include="Microsoft.Orleans.OrleansRuntime" Version="3.6.2" />
-    <PackageReference Include="Microsoft.Orleans.CodeGenerator.MSBuild" Version="3.6.2">
-      <PrivateAssets>all</PrivateAssets>
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
-    </PackageReference>
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="7.0.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
+    <PackageReference Include="Microsoft.Orleans.Server" Version="7.0.0" />
   </ItemGroup>
 </Project>

samples/HelloWorld/IHelloGrain.cs

@@ -1,10 +1,6 @@
-using System.Threading.Tasks;
-using Orleans;
+namespace HelloWorld;
 
-namespace HelloWorld
+public interface IHelloGrain : IGrainWithStringKey
 {
-    public interface IHelloGrain : IGrainWithStringKey
-    {
-        Task<string> SayHello(string greeting);
-    }
+    ValueTask<string> SayHello(string greeting);
 }

samples/HelloWorld/Program.cs

@@ -1,9 +1,6 @@
-using System;
 using HelloWorld;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
-using Orleans;
-using Orleans.Hosting; 
 
 // Configure the host
 using var host = new HostBuilder()
@@ -20,8 +17,12 @@
 var friend = grainFactory.GetGrain<IHelloGrain>("friend");
 
 // Call the grain and print the result to the console
-var result = await friend.SayHello("Good morning!"); 
-Console.WriteLine("\n\n{0}\n\n", result);
+var result = await friend.SayHello("Good morning!");
+Console.WriteLine($"""
+
+    {result}
+
+    """);
 
 Console.WriteLine("Orleans is running.\nPress Enter to terminate...");
 Console.ReadLine();

samples/HelloWorld/README.md

@@ -11,10 +11,10 @@ The sample consists of a single project which starts the Orleans-based applicati
 
 To start our tour of the application, open [`IHelloGrain.cs`](./IHelloGrain.cs) and you will find the following interface declaration:
 
-``` C#
+```csharp
 public interface IHelloGrain : IGrainWithStringKey
 {
-    Task<string> SayHello(string greeting);
+    ValueTask<string> SayHello(string greeting);
 }
 ```
 
@@ -23,16 +23,17 @@ We know it's a grain interface because it implements `IGrainWithStringKey`.
 This means that when we want to get a reference to a grain implementing `IHelloGrain`, we will identify the grain instance using an string value.
 In our case, as you will see later in [`Program.cs`](./Program.cs), we will use the string `"friend"` to identify the grain we wish to communicate with, but this could be any string:
 
-``` C#
+```csharp
 var friend = grainFactory.GetGrain<IHelloGrain>("friend");
 ```
 
 Now, open [`HelloGrain.cs`](./HelloGrain.cs) and we will see the implementation of our `IHelloGrain` interface:
 
-``` C#
+```csharp
 public class HelloGrain : Grain, IHelloGrain
 {
-    public Task<string> SayHello(string greeting) => Task.FromResult($"Hello, {greeting}!");
+    public ValueTask<string> SayHello(string greeting) => 
+        ValueTask.FromResult($"Hello, {greeting}!");
 }
 ```
 
@@ -43,7 +44,7 @@ That type is used to identify the grain classes in an application.
 
 Open [`Program.cs`](./Program.cs) to see how Orleans is configured:
 
-``` C#
+```csharp
 using var host = new HostBuilder()
     .UseOrleans(builder =>
     {