AddAspNetValidation

Registers the validation services, then scans the assemblies for validators and builds every request type's rules. Anything that cannot be built is refused here rather than on the first request that reaches it: two validators for one request type, a validator without a public parameterless constructor, a rule given no values to compare against, a blank date format, a field name matching no property, or a custom rule naming a type that does not implement the rule interface. Pair it with UseAspNetValidation, which adds the middleware but is otherwise separate.

Usage

using AlmightyShogun.AspNet.Core;
using AlmightyShogun.AspNet.Localization;
using AlmightyShogun.AspNet.RequestValidation;

builder.Services
    .AddMessageLocalization(builder.Configuration)
    .AddHttpErrorResponseWriter()
    .AddExceptionHandling()
    .AddAspNetValidation();

WARNING

AddMessageLocalization and AddHttpErrorResponseWriter must also be called. Without them, messages resolve to their raw keys such as validation.required.

MVC and minimal API integration

Controller integration is configured through MvcOptions rather than added, so the body and request validation filters take effect whenever the application registers controllers, whichever order the two calls are made in, and a minimal API application does not acquire the controller stack by asking for validation. SuppressImplicitRequiredAttributeForNonNullableReferenceTypes is turned on so a non-nullable property is not implicitly required by the framework. Requiredness stays something you declare with [Required] rather than something the type system decides.

ApiBehaviorOptions.InvalidModelStateResponseFactory is replaced so model-binding failures return the same shape as rule failures, and RouteHandlerOptions.ThrowOnBadRequest is enabled so a minimal API body that cannot be parsed reaches the middleware instead of returning a bare 400.

The validation exception handler is separate from the mapped exception handler in AlmightyShogun.AspNet.Core. Both can be registered at once: ASP.NET tries handlers in order and each returns false for exceptions it does not recognize, so they compose without interfering.

Parameters

assemblies: Assembly[]
Assemblies to scan for Validator<TRequest> subclasses, in search order. An empty array finds no validators; the overload taking no assembly falls back to the calling assembly.

Returns

The same IServiceCollection instance with validation services configured.

Type signature

public IServiceCollection AddAspNetValidation();

public IServiceCollection AddAspNetValidation(Assembly[] assemblies);