Remove DataAnnotations dependency in MEV public API

[Youssef1313]

Background and Motivation

Microsoft.Extensions.Validation is intended and designed to be general purpose validation solution. Today, ValidateContext which is a core part of its interfaces has a ValidationContext property. This is coupling MEV with DataAnnotations strongly.

Proposed API

  namespace Microsoft.Extensions.Validation;

  [Experimental("ASP0029", UrlFormat = "https://aka.ms/aspnet/analyzer/{0}")]
  public sealed class ValidateContext
  {
-     public required ValidationContext ValidationContext { get; set; }
+     public required IServiceProvider ServiceProvider { get; init; }
  }

The default implementations that we provide that are coupled to DataAnnotations will then be responsible for creating the correct ValidationContext when needed.

Usage Examples

Same as today, except that we users will only set the service provider instead of creating the whole ValidationContext. We will be responsible for creating it when needed.

Alternative Designs

Risks

[dotnet-policy-service]

Thank you for submitting this for API review. This will be reviewed by @dotnet/aspnet-api-review at the next meeting of the ASP.NET Core API Review group. Please ensure you take a look at the API review process documentation and ensure that:

• The PR contains changes to the reference-assembly that describe the API change. Or, you have included a snippet of reference-assembly-style code that illustrates the API change.
• The PR describes the impact to users, both positive (useful new APIs) and negative (breaking changes).
• Someone is assigned to "champion" this change in the meeting, and they understand the impact and design of the change.

[leveyp94-hash]

Good

[halter73]

API Review Notes:

• This removes some duplication, and makes the contract cleaner
  • It allows us to validate null Minimal API parameters too
• Microsoft.Extensions.Validation does keep its DataAnnotations dependency (it's in corelib anyway) for the default implementation, but now we don't use DataAnnotation in the outer abstractions. If we did have an M.E.V.Abstractions package, it wouldn't need a DataAnnotations dependency
• Should the IServiceProvider stay nullable like it was on ValidationContext?
  • Yes.
• Do we want to use init;? We don't use it for any other property in ValidateContext. They all have set;!
  • ValidationOptions can be made init-only as well

API Approved!

  namespace Microsoft.Extensions.Validation;

  [Experimental("ASP0029", UrlFormat = "https://aka.ms/aspnet/analyzer/{0}")]
  public sealed class ValidateContext
  {
-     public required ValidationContext ValidationContext { get; set; }
+     public IServiceProvider? ServiceProvider { get; init; }

-     public required ValidationOptions ValidationOptions { get; set; }
+     public required ValidationOptions ValidationOptions { get; init; }
  }