AspNetCore

Package 8: Mapsicle.AspNetCore

Minimal API helpers, map request/response bodies and validate them with endpoint filters.

Endpoint Filters

WithMappedRequest and WithValidatedMapping map the request body and store the result on HttpContext.Items. They do not touch the handler's own parameter, so declare the handler with its original source type and read the mapped value through GetMappedRequest<TDest>().

using Mapsicle.AspNetCore;

// Map only
app.MapPost("/users", (CreateUserRequest req, HttpContext ctx) =>
{
    var user = ctx.GetMappedRequest<User>();
    return Results.Ok(user);
})
.WithMappedRequest<CreateUserRequest, User>();

// Map and validate; returns 400 with { errors = ... } when the validator fails
app.MapPost("/users", (CreateUserRequest req, HttpContext ctx) =>
{
    var user = ctx.GetMappedRequest<User>();
    return Results.Ok(user);
})
.WithValidatedMapping<CreateUserRequest, User, CreateUserRequestValidator>();

GetMappedRequest<TDest>() throws InvalidOperationException if the endpoint has neither filter attached. There is also a TryGetMappedRequest<TDest>(out TDest? mapped) for callers that would rather check than catch.

Mapper resolution checks IMapper (Mapsicle.Fluent), then IMapperInstance (registered by Mapsicle.DependencyInjection's AddMapsicle), then falls back to the static Mapper. Validation always runs regardless of which one is resolved.

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