A new set of the Firefox Developer Tools features has just been uplifted to the Aurora channel. These features are available right now in Aurora, and will be in the Firefox 31 release in July. This release brings new tools, editor improvements, console and inspector features:

Editable box model

The Box Model tab in the Inspector is now editable for easy experimentation. Double-click any of the margin, border, or padding values to change its value for the currently selected element. Enter any valid CSS <length> value and use the Up / Down keys to increment or decrement the value by 1 . Alt-Up increments by 0.1 and Shift-Up increments by 10 . (development notes)

Eyedropper

New to the color picker in the Inspector is an Eyedropper tool that grabs the color from any pixel on the page. Select the current color by clicking or pressing Enter . Abort the operation by pressing Esc . Use the Up / Down keys to move by one pixel, and Shift-Up / Shift-Down to move by 10 pixels.

You can also use the eyedropper directly to copy a color to the clipboard by accessing it from Web Developer menu, or the toolbar icon that’s enabled by going to the settings panel and checking Available Toolbox Buttons > Grab a color from the page . (development notes)

Console stack traces

console.error , console.exception , and console.assert logs in the console now include the full stack from where the call was made. (development notes)

Styled console logs

On parity with other browser developer tools, you can now add style to console logging with the %c directive.

(development notes)

Copy as cURL

Replay any network request in the Network Monitor from the comfort of your own terminal. Right-click a request and select the copy as cURL menu item to copy a cURL command to the clipboard, including arguments for headers and data. (development notes)

Editor – multiple selection, Sublime Text keys

The source editor used in the developer tools has been upgraded to CodeMirror 4. With that brings:

Multiple selection. Hold down Ctrl / Cmd while selecting to get multiple selections.

Rectangle selection. Hold down Alt to select a column-aligned block of text.

Undo selection. Undo the last selection action with Ctrl-U / Cmd-U and redo with Alt-U / Shift-Cmd-U .

Sublime Text keybindings. To enable, go to about:config in the url bar and set devtools.editor.keymap to sublime .

Multiple selection in action:

development notes

Canvas Debugger

Debug animation frames in WebGL and 2d canvas contexts with the newly-landed canvas debugger. The canvas debugger is an experimental feature that has to be enabled in the setting panel. Multiple canvases are not yet supported (bug) as well as animations generated with setInterval (bug). The canvas debugger is described in more in this blog post.

(development notes)

Add-on Debugger

If you develop Firefox add-ons using the Add-on SDK, there’s now a much easier way to debug your add-on’s JavaScript modules. See the blog post for more details. (development notes)

Firefox 31: Add-on Debugger from Jordan Santell on Vimeo.

Other features

Expand descendants . Hold Alt while double-clicking a node in the Inspector to expand all of its children and descendants. (development notes)

. Hold while double-clicking a node in the Inspector to expand all of its children and descendants. (development notes) Persist network logs . Check Enable persistent logs in the settings panel to keep Network panel logs across reloads and navigations. (development notes)

. Check in the settings panel to keep Network panel logs across reloads and navigations. (development notes) JS warnings on by default . JavaScript warnings now show up in the Console by default. (development notes)

. JavaScript warnings now show up in the Console by default. (development notes) Scratchpad View menu. The Scratchpad tool now has a View menu with options for changing font size, hiding line numbers, wrapping text, and highlighting trailing spaces. (development notes)

Special thanks to the 38 contributors that added all the features and fixes in this release.

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