How to step through line by line when debugging JavaScript with Opera Dragonfly?

Question

I'm a long-time user of Opera as a browser for general usage and due to various annoyances with Firefox I decided to give Dragonfly a look. The first thing that has jumped out at me is when debugging JavaScript I can't seem to just step through my script line by line.

I'm using ASP.NET and my script is just a button click event. When I place my breakpoint on the first line of the function and click the button the breakpoint is hit as expected. It's here that I am confused. Dragonfly's window has four buttons on the top left - Continue, Step Into, Step Over and Step Out. If I click Step Over or hit F10 I am expecting that the debugger will step through the JavaScript just like Firebug but instead it seems to immediately skip over the rest of the function altogether. The same thing happens if I click Continue or hit F8. If I click Step Into or hit F11 I start descending into the jQuery JavaScript which is obiously not what I want!

Am I just missing something fundamental here? I'm using Opera 11.52 if it helps.

Just to add more information on the environment I'm working in, Here is a screenshot of my button click event with a breakpoint set on line 14. Execution pauses as expected when I click the button in the browser.

Now, I would expect that some keypress exists to simply bring me to line #15. In Firebug and the IE Dev Tools that keypress is F10. In Dragonfly though F10 seems to just skip the rest of the JavaScript code. The same applies to Shift+F11. F11 by itself brings me to this part of jquery.js which, as mentioned before, is not where I want to be.

Answer 1

this is a bug in Opera which sometimes causes problems when stepping over or out of functions with the Dragonfly debugger.

The only workaround is to set a breakpoint below the function you want to step over, use F10, clear the breakpoint and continue normally. For example, in the first screenshot above you'd set a new breakpoint on line 15, press F8, and clear the breakpoint on line 15 when stopped there. I know this is really annoying :-(

I've done a bit more work on trying to reproduce this bug so that it can get fixed. In Opera's (closed) bug tracker this is now tracked as issue CORE-42532, it seems we're making some progress there so hopefully this annoyance will be gone some day. Meanwhile good luck with your debugging!

Answer 2

Have you seen the documentation for the javascript debugger.