Make Result types constructors public

Background and Motivation

Result types were changed to be public but was decided to keep ctors internal to have a better design discussion.

The original proposal is described in #40656

Proposed API

namespace Microsoft.AspNetCore.Http;

public class EmptyHttpResult : IResult
{
-    public static readonly EmptyHttpResult Instance { get; } = new();
+    public EmptyHttpResult() {} 
}

public sealed partial class StatusCodeHttpResult : IResult
{
+    public StatusCodeHttpResult(int statusCode) {}
}

public class NoContentHttpResult : IResult
{
+    public NoContentHttpResult() {}
}

public class UnauthorizedHttpResult : IResult
{
+    public UnauthorizedHttpResult() {} 
}

public sealed class AcceptedAtRouteHttpResult : IResult
{
+    public AcceptedAtRouteHttpResult(string? routeName = null, 
+                                     object? routeValues = null, 
+                                     object? value = null) {}
}

public sealed class CreatedAtRouteHttpResult : IResult
{
+    public CreatedAtRouteHttpResult(string? routeName = null, 
+                                     object? routeValues = null, 
+                                     object? value = null) {}
}

public sealed class AcceptedHttpResult : IResult
{
+    public AcceptedHttpResult(string? location, object? value = null) {}
+    public AcceptedHttpResult(Uri locationUri, object? value = null) {}
}

public sealed class CreatedHttpResult : IResult
{
+    public CreatedHttpResult(string? location = null, object? value = null) {}
+    public CreatedHttpResult(Uri locationUri = null, object? value = null) {}
}

public sealed class BadRequestObjectHttpResult : IResult
{
+    public BadRequestObjectHttpResult(object? error = null) {}
}

public sealed class ConflictObjectHttpResult : IResult
{
+    public ConflictObjectHttpResult(object? error = null) {}
}

public sealed class NotFoundObjectHttpResult : IResult
{
+    public NotFoundObjectHttpResult(object? value = null) {}
}

public sealed class OkObjectHttpResult : IResult
{
+    public OkObjectHttpResult(object? value = null) {}
}

public sealed class UnprocessableEntityObjectHttpResult : IResult
{
+    public UnprocessableEntityObjectHttpResult(object? value = null) {}
}

public sealed class ProblemHttpResult : IResult
{
+    public ProblemHttpResult(ProblemDetails problemDetails) {}
+    public ProblemHttpResult(
+        string? detail = null,
+        string? instance = null,
+        int? statusCode = null,
+        string? title = null,
+        string? type = null,
+        IDictionary<string, object?>? extensions = null) {}
}

public sealed class JsonHttpResult : IResult
{
+    public JsonHttpResult(object? value = null, JsonSerializerOptions? jsonSerializerOptions = null) {}

-    public string ContentType { get; }
+    public string ContentType { get; init; }

-    public int? StatusCode { get; }
+    public int? StatusCode { get; init; }
}

public sealed partial class ContentHttpResult : IResult
{
+    public ContentHttpResult(string? content = null, string? contentType = null) {}

-    public int? StatusCode { get; }
+    public int? StatusCode { get; init; }
}

public sealed partial class FileContentHttpResult : IResult
{
+    public FileContentHttpResult(ReadOnlyMemory<byte> fileContents, string? contentType = null) {}

-    public bool EnableRangeProcessing { get; }
+    public bool EnableRangeProcessing { get; init; }

-    public EntityTagHeaderValue? EntityTag { get; }
+    public EntityTagHeaderValue? EntityTag { get; init; }

-    public string? FileDownloadName { get; }
+    public string? FileDownloadName { get; init; }

-    public DateTimeOffset? LastModified { get; }
+    public DateTimeOffset? LastModified { get; init; }
}

public sealed class FileStreamHttpResult : IResult
{
+    public FileStreamHttpResult(Stream fileStream, string? contentType = null) {}

-    public bool EnableRangeProcessing { get; }
+    public bool EnableRangeProcessing { get; init; }

-    public EntityTagHeaderValue? EntityTag { get; }
+    public EntityTagHeaderValue? EntityTag { get; init; }

-    public string? FileDownloadName { get; }
+    public string? FileDownloadName { get; init; }

-    public DateTimeOffset? LastModified { get; }
+    public DateTimeOffset? LastModified { get; init; }
}

public sealed partial class PhysicalFileHttpResult : IResult
{
+    public PhysicalFileHttpResult(string fileName, string? contentType = null) {}

-    public bool EnableRangeProcessing { get; }
+    public bool EnableRangeProcessing { get; init; }

-    public EntityTagHeaderValue? EntityTag { get; }
+    public EntityTagHeaderValue? EntityTag { get; init; }

-    public string? FileDownloadName { get; }
+    public string? FileDownloadName { get; init; }

-    public DateTimeOffset? LastModified { get; }
+    public DateTimeOffset? LastModified { get; init; }
}

public sealed class PushStreamHttpResult : IResult
{
+    public PushStreamHttpResult(Func<Stream, Task> streamWriterCallback, string? contentType = null) {}

-    public bool EnableRangeProcessing { get; }
+    public bool EnableRangeProcessing { get; init; }

-    public EntityTagHeaderValue? EntityTag { get; }
+    public EntityTagHeaderValue? EntityTag { get; init; }

-    public string? FileDownloadName { get; }
+    public string? FileDownloadName { get; init; }

-    public DateTimeOffset? LastModified { get; }
+    public DateTimeOffset? LastModified { get; init; }
}

public sealed partial class VirtualFileHttpResult : IResult
{
+    public VirtualFileHttpResult(string fileName, string? contentType = null) {}

-    public bool EnableRangeProcessing { get; }
+    public bool EnableRangeProcessing { get; init; }

-    public EntityTagHeaderValue? EntityTag { get; }
+    public EntityTagHeaderValue? EntityTag { get; init; }

-    public string? FileDownloadName { get; }
+    public string? FileDownloadName { get; init; }

-    public DateTimeOffset? LastModified { get; }
+    public DateTimeOffset? LastModified { get; init; }
}

public sealed partial class ChallengeHttpResult : IResult
{
+    public ChallengeHttpResult(AuthenticationProperties? properties = null) {}
+    public ChallengeHttpResult(AuthenticationProperties? properties, string authenticationScheme) {}
+    public ChallengeHttpResult(AuthenticationProperties? properties, IList<string> authenticationSchemes) {}
}

public sealed partial class ForbidHttpResult : IResult
{
+    public ForbidHttpResult (AuthenticationProperties? properties = null) {}
+    public ForbidHttpResult (AuthenticationProperties? properties, string authenticationScheme) {}
+    public ForbidHttpResult (AuthenticationProperties? properties, IList<string> authenticationSchemes) {}
}

public sealed partial class SignOutHttpResult : IResult
{
+    public SignOutHttpResult (AuthenticationProperties? properties = null) {}
+    public SignOutHttpResult (AuthenticationProperties? properties, string authenticationScheme) {}
+    public SignOutHttpResult (AuthenticationProperties? properties, IList<string> authenticationSchemes) {}
}

public sealed partial class SignInHttpResult : IResult
{
+    public SignInHttpResult(ClaimsPrincipal principal) {}

-    public string? AuthenticationScheme { get; }
+    public string? AuthenticationScheme { get; init; }

-    public AuthenticationProperties? Properties { get; }
+    public AuthenticationProperties? Properties { get; init; }
}

public sealed partial class RedirectHttpResult : IResult
{
+    public RedirectHttpResult(string url, bool acceptLocalUrlOnly = false) {}

-    public bool Permanent { get; }
+    public bool Permanent { get; init; }

-    public bool PreserveMethod { get; }
+    public bool PreserveMethod { get; init; }
}

public sealed partial class RedirectToRouteHttpResult : IResult
{
+    public RedirectToRouteHttpResult(string? routeName = null, object? routeValues = null) {}

-    public bool Permanent { get; }
+    public bool Permanent { get; init; }

-    public bool PreserveMethod { get; }
+    public bool PreserveMethod { get; init; }

-    public string Fragment { get; }
+    public string Fragment { get; init; }
}

[davidfowl]

My thinking is we should get rid of the public Instance properties altogether and just return the shared instance from Results. and Results.Typed. methods.

Also the non typed ones. I guess I wasn’t clear but I expected us to change the existing impl to cache.

[halter73]

If we decide to add constructors to any of these types, I think every one of them should have at least one constructor even if there’s an equivalent Instance property that’s more efficient. Most people aren’t going to care about one extra allocation a request, so I don’t think that’s an excuse to make the API less consistent.

My thinking is we should get rid of the public Instance properties altogether and just return the shared instance from Results. and Results.Typed. methods.