ASP0010: Do not use UseStartup with WebApplicationBuilder.WebHost

Cause

UseStartup can't be used with WebApplicationBuilder.WebHost.

Rule description

The WebApplicationBuilder doesn't support configuration via a Startup class.

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.UseStartup<Startup>();

var app = builder.Build();

app.Run();

How to fix violations

To fix a violation of this rule, leverage the Configuration and Services properties on the WebApplicationBuilder to modify configuration and DI directly, without the need for a startup class.

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddAuthentication();

var app = builder.Build();

app.Run();

When to suppress warnings

Do not suppress a warning from this rule. A misconfigured application can result in unexpected behavior at runtime.