podnoms/server/Utils/Errors.cs

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc.ModelBinding;

namespace PodNoms.Api.Utils {
    public static class Errors {
        public static ModelStateDictionary AddErrorsToModelState(IdentityResult identityResult, ModelStateDictionary modelState) {
            foreach (var e in identityResult.Errors) {
                modelState.TryAddModelError(e.Code, e.Description);
            }

            return modelState;
        }

        public static ModelStateDictionary AddErrorToModelState(string code, string description, ModelStateDictionary modelState) {
            modelState.TryAddModelError(code, description);
            return modelState;
        }
    }
}