Ask HN: Webdevs, designers: what devtools should we (Mozilla) build in Firefox?

1. The debugger has no REPL. If you evaluate a statement in the console, it doesn't run in the current stack frame and has no access to locals, etc. The only way to execute a statement in the current stack frame is to add it as a "watch" and then delete it.

2. There's no way to get to the console from the debugger and vice versa. You have to activate them independently in two steps, which is annoying because I almost always want both of them. Also, they stack in a different order depending on the order they're activated, which is unnecessarily confusing.

3. There's no way to "pause on uncaught exceptions". It's either "pause on all thrown exceptions" or nothing. Also, the UI is buried in a menu. Exception breakpoints should be shown in the breakpoint pane like other breakpoints, and should be filterable by exception type and whether the exception is caught or not.

I tried to clarify this in another comment: https://news.ycombinator.com/item?id=5326873 - let me know if I can clarify further.

This is how I tend to work: I load up an app. I set up my credentials (by logging in or setting a particular cookie manually, for example). I debug using Firebug, mainly using the DOM view, the console and the JavaScript REPL. Then I might change my credentials to see the page as a different user, for example. I clear the cache now and then, and I clear my cookies often. I also change things like cookie preferences and turn JavaScript on/off to see how my app behaves. I also work on multiple projects concurrently, so I frequently need to switch, meaning yet again to clear the browser state.

In other words, I need the browser as a clean slate. I frequently need to throw its state away, and I rarely if ever run pages as "myself".

I'm a Chrome user, so for this reason I currently use Firefox as my dedicated debug browser. This means I can always throw away my browser state, and I can close Firefox when I'm done with work. Firefox is a resource hog on OS X, and will frequently sit consuming 5-10% CPU even when idle, so this is actually important. I almost never use Chrome for debugging, not just because its DOM view and console are both much worse than Firebug's, but because it's my browser. (Yes, I know that Chrome supports per-window profiles, but Chrome just isn't good enough for debugging.)

My ideal development tool would be a thin shell around a web browser component. It would be chock full of techy dev stuff, and it would not compromise the dev aspect in favour of user-friendliness; unlike today's browsers, everything could be provided natively by the tool instead of inserted awkwardly by "extensions". It would do away with user-facing features like browser extensions, fancy history and bookmarks. In other words, it would be a hard core, bare-bones development tool.

This tool would support "projects"; each project being is a browser window, and each browser window is logically compartmentalized, with its own cookie database, history, settings, etc., with the option to save certain things like cookies, so that I can "bake" current browser state and recall it later. The ideal solution would be for each window to be able to embed different browser engines; there is no particular technical reason why this should not work, although it would be a little more work to implement.

I actually started writing an app like this for OS X that embeds WebKit. It was surprisingly simple, and I got a decent DOM inspector view and style editor working, but then my mind wandered off to work on something else. I may pick this project up again at some point.