Is WinRT javascript compiles into assembly?

Question

I don't clearly understand how Microsoft embeds javascript for Metro Apps.

When I debug simple metro app in Visual Studio written on javascript and hit 'Ctrl+Alt+D - Go To Assembly', there is on any assembly code, but for other language there is.

So how javascript executes on WinRT, is it just browser which have some API access or something more?

Answer 1

JavaScript for a Windows Store App is executed inside the "app host" process (WWAHost.exe) in the same way it is in a browser, using just-in-time compilation. This means there is no machine code loaded into a place where you could see it in the debugger. The app host is what makes WinRT APIs available, which the same engine in the browser does not.

So there is no assembly code for you to look at. It's for this same reason that you can step through JavaScript in the debugger even if you built a Release target.