IConfigureOptions isn't called for authentication (named) options

[khellang]

After a Twitter discussion with @mwadams, we discovered this weird thing...

The OptionsFactory.Create method seems to only call registered IConfigureOptions<T> when name == Options.DefaultName:

Options/src/Microsoft.Extensions.Options/OptionsFactory.cs

Lines 28 to 47 in e71178f

	public TOptions Create(string name)
	{
	var options = new TOptions();
	foreach (var setup in _setups)
	{
	if (setup is IConfigureNamedOptions<TOptions> namedSetup)
	{
	namedSetup.Configure(name, options);
	}
	else if (name == Options.DefaultName)
	{
	setup.Configure(options);
	}
	}
	foreach (var post in _postConfigures)
	{
	post.PostConfigure(name, options);
	}
	return options;
	}

This results in IConfigureOptions<T> not being called when options are requested from authentication handlers (or any other named options):

https://github.com/aspnet/Security/blob/488eb44467eb677eab62bdc49aa6255cc1be3119/src/Microsoft.AspNetCore.Authentication/AuthenticationHandler.cs#L89

Why is this? Was this intended or a regression? It seems like a weird, artificial restriction to have. Not to mention the inconsistently configured named/default options you'd have around.

A workaround is to just use the exact same class, but implement IPostConfigureOptions<T> instead.

// @HaoK (from commit 52ab5f1)

[mwadams]

The 1.1 behaviour was for this to be called for all handlers.

[khellang]

The 1.1 behaviour was for this to be called for all handlers.

Yes, judging by commit 52ab5f1, it was introduced in 2.0.0-preview2.

[HaoK]

Yes Auth 2.0 uses named options, IConfigureOptions are equivalent to IConfigureNamed options with name = Options.DefaultName

[HaoK]

IPostConfigureOptions works because it supports names since its new in 2.0, we wanted to preserve existing behavior for existing users of IOptions/IConfigureOptions so we left those alone and added IConfigureNamedOptions.

[HaoK]

You need to switch to IConfigureNamedOptions to be able to target the correct authentication scheme in 2.0, this breaking change was intentional

[HaoK]

I added this to the known issues/breaking changes section at the bottom of the Auth 2.0 announcement: aspnet/Announcements#262

[khellang]

Alright. I think we're done here 👍