Object must implement IConvertible requirement?

[e-mair]

Hi,

I am facing an issue regarding the use of generics. I essentially try to pass an array of items to a function via Engine.Invoke, which in turn, gives me a Object must implement IConvertible error. Had a look through issues and found #15 - IConvertible requirement, not sure if this is related?

I have a script that accepts an array of people, that could look something like this:

let ipsum = (function(people) {
    return people.map(p => {
        return {
            FirstName: p.FirstName,
            Surname: p.LastName,
            FullName: p.FirstName + " " + p.MiddleName + " " + p.LastName,
            EmployeeNumber: p.MainEmployment.EmpNo
        }
    });
});

I have written an engine wrapper in C#, of which, has a ModifyItem method with the following body:

public BusinessResult<object> ModifyItem<T>(OCSDataProfileConfigurationSVC config, T item)
{
     try
     {
          var safeProfileName = GenerateRandomVariableName();
          var safeCollectionName = GenerateRandomVariableName();
          var jsFunction = Engine.Execute($"let {safeProfileName} = {config.Script}").Evaluate(safeProfileName);
          var modifiedItem = ((IList<object>)Engine.Invoke(jsFunction, new T[] { item }).ToObject()).FirstOrDefault();

          if (modifiedItem is null)
               throw new ArgumentNullException(nameof(modifiedItem));

          return BusinessResult.Ok(modifiedItem);
     }
     catch (Exception e)
     {
          _logger.LogError("Failed to modify item of {type}: {errorMessage}", typeof(T).Name, e.Message);
          return BusinessResult.Fail<object>(e);
     }
}

Notice that I am initializing a new array of T when I call Engine.Invoke - we do this so that our scripts are generalized; we're essentially fooling the script into handling a collection of items when there will always be one item.

Any help would be appreciated! 🙏🏻

[lahma]

Could you please formulate a smallest possible failing test case (xUnit, NUnit, console program) for this problem? It would make investigating easier.

[e-mair]

Dependencies

Person Class

public class Person
{
      public string FirstName { get; set; }

      public string LastName { get; set; }

     public long EmpNo { get; set; }

     public long CompanyId { get; set; }
}

This is the object I am trying to pass along to my JavaScript function.

JavaScript

(function(people) {
    return people.map(p => {
        return {
            FirstName: p.FirstName,
            Surname: p.LastName,
            FullName: p.FirstName + " " + p.LastName,
            EmployeeNumber: p.EmpNo
        }
    });
});

This is the simple function we're attempting to call. It is designed to support a collection of people that need to be processed via .map().

I'll write a brief unit test later and post back what I find (if anything). Ideally I'd avoid having to implement IConvertible on my classes as I don't want to interfere with serialization.