When indexer is present, Evaluate only considers the declared type of a property, not the type of the value.

[EricLVertiGIS]

Version/platform/runtime used

Jint 4.1.0 / NET 9.0.302

Describe the bug

When indexer is present, Evaluate only considers the declared type of a property, not the type of the value. So if the property is declared as type Wrapper, but the value assigned is a subclass of Wrapper, Jint still treats it like a Wrapper type.

To Reproduce

Create a class called Wrapper with a dictionary indexer

private readonly IDictionary<string, object?> _exports = new Dictionary<string, object?>();

/// <summary>
/// Indexer that makes exports available.
/// </summary>
public object? this[string name]
{
    get
    {
        if (_exports.ContainsKey(name))
        {
            return _exports[name];
        }

        return null;
    }

    set
    {
        _exports[name] = value;
    }
}

Then create a class called GeometryWrapper that subclasses Wrapper. Have GeometryWrapper declare a double property like public double X { get; }, set it to some value in GeometryWrapper's constructor. Then create a class called Feature that has a property public Wrapper Geometry { get; set; }.

Finally, in main, try to evaluate feature.geometry.x.

var engine = new Engine();

var feature = new Feature();
var geometryWrapper = new GeometryWrapper();

engine.SetValue("feature", feature);

feature.Geometry = geometryWrapper;

var x = engine.Evaluate("feature.geometry.x");

Expected behavior

Since feature.geometry.x's value is a GeometryWrapper, we would expect feature.geometry.x to be a double.

Additional context

Instead of a double, feature.geometry.x is null. It seems like Jint thinks feautre.geometry is of type Wrapper so it only searched the indexer for x. But in fact feature.geometry is GeometryWrapper so it should have an X property.

I also found that if X is declared as an abstract property in Wrapper and let GeometryWrapper implement it, then X can be found. Removing the indexer from Wrapper also fixes the issue.

[lahma]

Maybe you could propose a change/fix with a pull request? There's a lot of different outcomes with interop...