sebastienros.jint/Jint/Native/PrivateName.cs

using Esprima.Ast;
using Jint.Runtime;

namespace Jint.Native;

/// <summary>
/// Private names are a bit like symbols, they follow reference equality so that each one is globally to object,
/// only exception to the rule is get/set pair which should share same private name.
/// </summary>
internal sealed class PrivateName : JsValue, IEquatable<PrivateName>
{
    private readonly PrivateIdentifier _identifier;

    public PrivateName(PrivateIdentifier identifier) : base(InternalTypes.PrivateName)
    {
        _identifier = identifier;
        Description = identifier.Name;
    }

    public string Description { get; }

    public override string ToString() => _identifier.Name;

    public override object ToObject() => throw new NotImplementedException();

    public override bool Equals(object? obj)
    {
        return Equals(obj as PrivateName);
    }

    public override bool Equals(JsValue? other)
    {
        return Equals(other as PrivateName);
    }

    public bool Equals(PrivateName? other)
    {
        if (ReferenceEquals(null, other))
        {
            return false;
        }

        if (ReferenceEquals(this, other))
        {
            return true;
        }

        return ReferenceEquals(this, other);
    }

    public override int GetHashCode()
    {
        return StringComparer.Ordinal.GetHashCode(_identifier.Name);
    }
}

/// <summary>
/// Compares private identifiers by their name instead of reference equality.
/// </summary>
internal sealed class PrivateIdentifierNameComparer : IEqualityComparer<PrivateIdentifier>
{
    internal static readonly PrivateIdentifierNameComparer _instance = new();

    public bool Equals(PrivateIdentifier? x, PrivateIdentifier? y) => string.Equals(x?.Name, y?.Name, StringComparison.Ordinal);

    public int GetHashCode(PrivateIdentifier obj) => StringComparer.Ordinal.GetHashCode(obj.Name);
}