Web app fails to load when waiting asynchronously inside an IHostedService

[MarcPilgaard]

[EDIT by guardrex to add metadata]

In a fresh solution, using the Blazor Web App template with interactive render mode as Server I noticed the example would fail to load if I awaited an asynchronous task inside a hosted IHostedService

In program.cs:

builder.Services.AddHostedService<SomeRandomService>();

Then I'll create the following file:

public class SomeRandomService : IHostedService
{
    public async Task StartAsync(CancellationToken cancellationToken)
    {
        while (true)
        {
            await Task.Delay(10000, cancellationToken);
        }
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        throw new NotImplementedException();
    }
}

But if I converted the service to use BackgroundService instead, it would work as intended:

public class SomeRandomService : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (true)
        {
            await Task.Delay(10000, stoppingToken);
        }
    }
}

Are raw IHostedServices a no-no in Blazor or what am I missing?

Using .NET 8.0.401

Page URL

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/host/hosted-services?view=aspnetcore-9.0&tabs=visual-studio

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/fundamentals/host/hosted-services.md

Document ID

b2dece1f-15b8-03af-6d52-7cc070432b4b

Article author

— ... Tom takes care of this one, but I'll place a quick line or two and ping him for review.

[guardrex]

Hello @MarcPilgaard ... Please open this for the product unit ...

https://github.com/dotnet/aspnetcore/issues

Please add ...

cc: @guardrex https://github.com/dotnet/AspNetCore.Docs/issues/33902

... to the bottom of your opening comment so that I can follow the discussion.