The "Main()" documentation is misleading about async

[vernou]

Type of issue

Other (describe below)

Description

In the documentation Main() and command-line arguments, I found the part about async misleading.

For example this part :

The following list shows valid Main signatures:

public static void Main() { }
public static int Main() { }
public static void Main(string[] args) { }
public static int Main(string[] args) { }
public static async Task Main() { }
public static async Task<int> Main() { }
public static async Task Main(string[] args) { }
public static async Task<int> Main(string[] args) { }

Like explained by :

If and only if Main returns a Task or Task, the declaration of Main may include the async modifier. This specifically excludes an async void Main method.

This other signatures is also valid :

public static Task Main() { }
public static Task<int> Main() { }
public static Task Main(string[] args) { }
public static Task<int> Main(string[] args) { }

Also, the return type of a method is not part of the signature of the method. I think the term declaration is better in this context.

---

Moreover, the boilerplate code is :

class AsyncMainReturnValTest
{
    public static void Main()
    {
        AsyncConsoleWork().GetAwaiter().GetResult();
    }

    private static async Task<int> AsyncConsoleWork()
    {
        // Main body here
        return 0;
    }
}

The result need to be returned, so this boilerplate code should be :

class AsyncMainReturnValTest
{
    public static void Main()
    {
        return AsyncConsoleWork().GetAwaiter().GetResult();
    }

    private static async Task<int> AsyncConsoleWork()
    {
        // Main body here
        return 0;
    }
}

---

If you agree, I can do a PR to improve this page.

Page URL

https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/program-structure/main-command-line

Content source URL

https://github.com/dotnet/docs/blob/main/docs/csharp/fundamentals/program-structure/main-command-line.md

Document Version Independent Id

d942d65a-87e4-1525-bd94-b005f1b7cbac

Article author

@BillWagner

Metadata

• ID: 06ef4bd7-7012-8afd-721a-a4c31db20202
• Service: dotnet-csharp
• Sub-service: fundamentals

[BillWagner]

Hi @vernou I like some of these ideas.

This other signatures is also valid :

Yes, the async modifier is optional. Let's make this change. However, it's important to keep the restriction that async void isn't valid for Main.

I think the term declaration is better in this context.

Yes. "declaration" should be used instead of "signature" throughout this article.

Moreover, the boilerplate code is :

There are two examples here. I'd prefer changing the first declaration of AsyncConsoleWork to return a Task instead of a Task<int>. The two samples should show the difference between returning Task and Task<int.

Thanks for volunteering to address these. I'll watch for a PR.