sebastienros.jint/Jint/Collections/ObjectTraverseStack.cs

using Jint.Native;
using Jint.Runtime;

namespace Jint.Collections;

/// <summary>
/// Helps traversing objects and checks for cyclic references.
/// </summary>
internal sealed class ObjectTraverseStack
{
    private readonly Engine _engine;
    private readonly Stack<object> _stack = new();

    public ObjectTraverseStack(Engine engine)
    {
        _engine = engine;
    }

    public bool TryEnter(JsValue value)
    {
        if (value is null)
        {
            Throw.ArgumentNullException(nameof(value));
        }

        if (_stack.Contains(value))
        {
            return false;
        }

        _stack.Push(value);

        return true;
    }

    public void Enter(JsValue value)
    {
        if (!TryEnter(value))
        {
            Throw.TypeError(_engine.Realm, "Cyclic reference detected.");
        }
    }

    public void Exit()
    {
        _stack.Pop();
    }
}