Does it work for you? Your comment seems to suggest it mostly works fine for you but for me. For me it's 100% unusable. 1. JSFiddle. Run a fiddle with a loop (

Does it work for you? Your comment seems to suggest it mostly works fine for you but for me. For me it's 100% unusable. 1. JSFiddle. Run a fiddle with a loop (setTimeout/setInterval/requestAnimationFrame). Try to find it in the debugger. Fail 2. Add a `debugger` statement in the loop. Watch as Firefox doesn't display the code in the debugger 3. Add a syntax error, see message in console, click link to code, firefox doesn't display code.