How to get JS exception details so I can log them

[amp64]

If I run the host app under the VS debugger I can see the js exceptions, exposed via Jint.Runtime.JavaScriptException in C#, and when they hit there I can see everything I need.

However, if I'm not running under a debugger, I want to be able to log that same information, but can't see any way of getting it. I can't catch that exception, as its already being caught somewhere in Jint.

I already log js execution line-by-line via a DebugHandler which is great, I have a full post-mortem debugger hooked up to that log. But I need to see the JS exceptions.

[lahma]

Hi! We've added an ExceptionThrown event to the DebugHandler that does exactly this — it fires for all JavaScript exceptions (both caught and uncaught), analogous to first-chance exception notifications in the .NET debugger.

Here's how to use it:

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

engine.Debugger.ExceptionThrown += (sender, args) =>
{
    // args.ThrownValue - the JS value that was thrown
    // args.Location    - source file, line, and column
    // args.CallStack   - full call stack at the throw point
    Console.WriteLine($"JS Exception at line {args.Location.Start.Line}: {args.ThrownValue}");
};

engine.Execute(script);

This works for:

• Explicit throw statements
• Implicit errors (TypeError, RangeError, ReferenceError, SyntaxError)
• Exceptions caught by try/catch (the event fires before the catch runs)

The event only fires when DebugMode() is enabled and has zero overhead when no subscriber is attached.

See PR #2375.

[amp64]

Perfect, thank you!