Converting Invalid Result to ActionResult throws System.ArgumentNullException when Identifier is not set on ValidationError

[uflowie]

Summary

When returning an InvalidResult that is lacking an identifier (ie it has been instantiated with the constructor that takes just the ErrorMessage as a string), converting it into an ActionResult using the TranslateResultToActionResult attribute, the server will throw a System.ArgumentNullException and return StatusCode 500. I have created a minimal reproducible example here: https://github.com/uflowie/InvalidResult.

Expected Behavior

Using a parameterized constructor should instantiate a result that can be translated to an ActionResult without throwing unexpected Exceptions.

Version

Ardalis.Result: 8.0 Ardalis.Result.AspNetCore: 8.0.0 dotnet: net8.0

[ardalis]

Confirmed. This should not throw (or should not be allowed):

        return Result<int>.Invalid(new ValidationError("foo"));

Stack trace from error:

System.ArgumentNullException: Value cannot be null. (Parameter 'key')
   at System.ArgumentNullException.Throw(String paramName)
   at System.ArgumentNullException.ThrowIfNull(Object argument, String paramName)
   at Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary.AddModelError(String key, String errorMessage)
   at Ardalis.Result.AspNetCore.ResultStatusMap.BadRequest(ControllerBase controller, IResult result)
   at Ardalis.Result.AspNetCore.ResultStatusOptions.<>c__DisplayClass17_0`1.<With>b__0(ControllerBase ctrlr, IResult result)
   at Ardalis.Result.AspNetCore.ResultExtensions.ToActionResult(ControllerBase controller, IResult result)
   at Ardalis.Result.AspNetCore.TranslateResultToActionResultAttribute.OnActionExecuted(ActionExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Filters.ActionFilterAttribute.OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
   at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

[uflowie]

Awesome, thanks!