JV.ResultUtilities.AspNetCore 11.0.0

JV.ResultUtilities.AspNetCore

The ASP.NET Core bridge for JV.ResultUtilities: one exception handler that turns a thrown ResultException into an RFC 9457 problem body, with the HTTP status coming from the failing key, structured errors / validation extensions for clients, and request validation through AbstractValidator<T>.

// Program.cs
builder.Services.AddControllers();
builder.Services.AddResultProblemDetails<ResxResultMessageTranslator>(options =>
{
    options.MapStatus(ValidationKeys.Legacy.Locked, 423);   // for keys you do not own
});
builder.Services.AddResultValidation(typeof(Program).Assembly);

var app = builder.Build();
app.UseExceptionHandler();
app.MapControllers();

// Domain: the key says what it is over HTTP
public static readonly ValidationKeyDefinition NotFound =
    ValidationKeyDefinition.Create("User.NotFound").WithGuidParameter("id")
        .WithHttpStatusCode(HttpStatusCode.NotFound);   // core helper; WithHttpStatus(404) is the int form

// Controller: no HasError ladder
var (result, user) = await service.GetAsync(id, ct);
result.ThrowIfFailure();            // → 404 application/problem+json
return Ok(UserResponse.Map(user));

The body:

{
  "type": "https://tools.ietf.org/html/rfc9110#section-15.5.5",
  "title": "Not Found",
  "status": 404,
  "detail": "User 3f2c… was not found.",
  "instance": "GET /api/users/3f2c…",
  "traceId": "…", "requestId": "…",
  "errors":     { "": ["User 3f2c… was not found."] },
  "validation": [{ "key": "User.NotFound", "field": null, "message": "…", "parameters": { "id": "3f2c…" } }]
}

• errors uses ASP.NET Core's own ValidationProblemDetails shape (field → messages), so a client's existing model-binding error path handles domain failures too.
• validation is lossless: stable key to branch on, field, translated message, named raw parameters.
• The handler answers only ResultException. Anything else returns false and the framework's default handling logs it and writes a 500 with no exception message — so this package never leaks one.
• Status per message: WithHttpStatusCode (or the int WithHttpStatus) on the key, else options.MapStatus, else DefaultStatusCode (400). Several messages: all equal → that status; otherwise any 5xx → the highest, else the default.
• Validation failures are logged at Information (configurable). They are client errors.

IResultMessageTranslator is the one seam you implement: string Translate(ValidationMessage). The fallback returns the key. ValidateModelFilter runs every registered IValidator against matching action arguments before the action and throws the same ResultException, so request-shape and business-rule failures share one wire shape.