Firefox Developer Edition Brings Popup Debugging
Mozilla has released Developer Edition 47 for Firefox, bringing new features to improve add-on debugging.
In the Mozilla Hacks post Developer Edition 47 – User agent emulation, popup debugging and more authors Tim Nguyen (a developer tools contributor) and Firefox engineer Brian Grinstead explain that the debugging panel can be kept open by changing its behaviour via the Browser Toolbox. This will allow developers to open the popup and return to the Browser Toolbox.
Nguyen and Grinstead said:
"In this release, we’ve made inspecting popups much easier. You can now lock popups so they don’t disappear once you click away. To use this feature, you need to launch the Browser Toolbox and click the icon with the four squares located in the top-right corner of the toolbox."
A screencast of the action can be viewed here.
Also new in the browser's latest Developer Edition is an improved dominator view for debugging memory-intensive applications. Building on previous work, Mozilla has added a retaining paths panel. According to MDN Developer Tools:
The Retaining Paths panel shows you, for a given node, the 5 shortest paths back from this node to a GC root. This enables you to see all the nodes that are keeping the given node from being garbage-collected. If you suspect that an object is being leaked, this will show you exactly which objects are holding a reference to it.
Also notable in the 47 release is the removal of the 3D view, that Nguyen and Grinstead explain conflicts with the multi-process version of Firefox.
"There have been some discussions about bringing it back in a way that will visualize things in a more useful way, but nothing is planned. Probably that work would happen in an addon," Grinstead replied.
Mozilla launched Firefox Developer Edition, its browser created specifically for developers, in November 2014. Marking 10 years since the 1.0 release of Firefox, the rebranded Aurora release continues to give developers a focal point to streamline their development workflow.
Developers can download nighly versions of the Firefox browser, including the special Developer Edition.