NonNullableReferenceTypesAsRequired should not consider MvcOptions

[pinkfloydx33]

Describe the bug

The NonNullableReferenceTypesAsRequired option only works if you've also set the MvcOptions.SuppressImplicitRequiredAttributeForNonNullableReferenceTypes to false

This is surprising. If I opt into a feature it shouldn't be predicated on an MVC-specific option also being enabled.

Expected behavior

NonNullableReferenceTypesAsRequired should work no matter how the MvcOption is configured.

Actual behavior

The feature does not work if MvcOptions.SuppressImplicitRequiredAttributeForNonNullableReferenceTypes is true

Steps to reproduce

No response

Exception(s) (if any)

No response

Swashbuckle.AspNetCore version

7.2.0

.NET Version

Net9

Anything else?

We are trying to upgrade to NET9. We've had a custom filter in place for years that does the exact same thing as the new NonNullableReferenceTypesAsRequired option and we were excited to finally be able to remove it.

Unfortunately we explicitly configure the MvcOptions.SuppressImplicitRequiredAttributeForNonNullableReferenceTypes to true. This is because the MVC option is a huge hammer. We'd like our API to be forgiving in certain things it accepts, but have the API specification indicate the desired state of affairs. Required-ness is also not limited to inputs, as read-only schemas can indicate properties are required, ie. that they will exist in the returned data. We also rely on the readonly properties when passing our api specification off to code generators, but again don't want to enforce it across the board at the MVC layer except where done explicitly.

In the PR that added this, there was a little discussion on including the MvcOptions, but it was mostly about breaking APIs.

It's also surprising that if I were building a netstandard library and opt into the feature that it would work since it ifdef's around, which feels very inconsistent. Also given that this is predicated on an MVC-specific option, does that mean the filter won't work properly with minimal apis?

Please consider either removing the dependency on MvcOptions or providing us a way to forcefully opt-in. We'll keep our custom filter in the meantime, bummer!

[martincostello]

Relevant line of code for this request:

Swashbuckle.AspNetCore/src/Swashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/SchemaGenerator.cs

Lines 442 to 446 in 0c61531

	var markNonNullableTypeAsRequired = _generatorOptions.NonNullableReferenceTypesAsRequired
	#if !NETSTANDARD2_0
	&& (!_mvcOptions?.Value.SuppressImplicitRequiredAttributeForNonNullableReferenceTypes ?? true)
	#endif
	&& (dataProperty.MemberInfo?.IsNonNullableReferenceType() ?? false);