Why doesn't .AddCors have an overload for Action<ISerivceProvider> ?

[PureKrome]

👋🏻 G'Day all,

Problem

.AddCors doesn't make it easy to setup with using values from the "configuration" sources.

Details

Can we have an overload for .AddCors which accepts an IServiceProvider so we can then extract registered services from the DI/IoC container like our strongly type configuration values!

A common use case when registering services is that we need access to the IServiceProvider so we can extract Services/RequiredServices that have been registered.

Here's a great example -> database:

services.AddDbContext<MyDbContext>((serviceProvider, options) => 
{
    var dbSettings = serviceProvider.GetRequiredService<IOptions<DatabaseSettings>>().Value;
    options.UseSqlServer(dbSettings.ConnectionString);
});
    
services.AddScoped<IDapperContext>(serviceProvider => 
{
    var dbSettings = serviceProvider.GetRequiredService<IOptions<DatabaseSettings>>().Value;
    return new DapperContext(dbSettings.ConnectionString);
});

The beauty of this is that we can read some Configuration information before we start registering our services with DI/IoC. When we need the instance (in this case, some IDapperContext or MyDbContext) it can grab the IOptions configuration information. Nice 😻

Now this is not possible with .AddCors :(

We have to know everything there and then. Can we please have .AddCors have an overload:

public static IServiceCollection AddCors(this IServiceCollection services, Action<IServiceProvider, CorsOptions> setupAction)
{
}

so this way we can grab configuration values from our IOptions which have been previously read/parsed/strongly-typed/registered.

e.g.

builder.Services.AddCors((serviceProvider, options) => 
{
    // Strongly-typed configuration values.
    var corsSettings = serviceProvider.GetRequiredService<IOptions<CorsSettings>>().Value;
    
    options.AddDefaultPolicy(policy =>
    {
        policy.WithOrigins(corsSettings.Origins) // Value is from config! 🚀
              .AllowAnyHeader()
              .AllowAnyMethod();
    });
    
    return services;
});

thank you ASP.NET Core team! 🍰

[PureKrome]

OMG closing - I've already asked this last year :(

ref: #57750