sebastienros.jint/Jint.Tests/Runtime/Debugger/DebugHandlerTests.cs

using Jint.Native.Object;
using Jint.Runtime.Debugger;

#pragma warning disable 618

namespace Jint.Tests.Runtime.Debugger;

public class DebugHandlerTests
{
    [Fact]
    public void AvoidsPauseRecursion()
    {
        // While the DebugHandler is in a paused state, it shouldn't relay further OnStep calls to Break/Step.
        // Such calls would occur e.g. if Step/Break event handlers evaluate accessors. Failing to avoid
        // reentrance in a multithreaded environment (e.g. using ManualResetEvent(Slim)) would cause
        // a deadlock.
        string script = @"
                var obj = { get name() { 'fail'; return 'Smith'; } };
                'target';
            ";

        var engine = new Engine(options => options.DebugMode().InitialStepMode(StepMode.Into));

        bool didPropertyAccess = false;

        engine.Debugger.Step += (sender, info) =>
        {
            // We should never reach "fail", because the only way it's executed is from
            // within this Step handler
            Assert.False(info.ReachedLiteral("fail"));

            if (info.ReachedLiteral("target"))
            {
                var obj = info.CurrentScopeChain[0].GetBindingValue("obj") as ObjectInstance;
                var prop = obj.GetOwnProperty("name");
                // This is where reentrance would occur:
                var value = engine.Invoke(prop.Get);
                didPropertyAccess = true;
            }
            return StepMode.Into;
        };

        engine.Execute(script);

        Assert.True(didPropertyAccess);
    }
}