Welcome to my corner of the web!
My name is Mihai and I work on the Firefox developer tools.
When it comes to web development, I like both server-side and
client-side work. I am mainly interested in web browsers, web
standards and related technologies.
3 August 2013, 10:11
In early 2010 when I applied for an internship at Mozilla I was
anxious. It was a kind of test for what I learned and for the value
of the projects I did up until that point. That is when I met my
first manager. When I was invited to join the new developer tools
team, I was thrilled, excited and really happy that somehow "I did
it!". I did it in the sense that "yes! now I can do real work!",
and yes, since 2010 I work on things that make a difference. This
was, and still is, the job I really wanted to have. Back then, the
team was preparing the initial versions of the Web Console and of
the Inspector. We released the Web Console in Firefox 4.
In July 2010, when I started to work with the team, I was new to
then I learned a lot more about technologies, about what it takes
to work in a big project, what it takes to work in a team and I
also learned about how managers work. I had no clue about a lot of
things, and learning never ends - which is what I really enjoy
about the work I am doing.
I had the opportunity to meet the whole team and other colleagues
from Mozilla on several occasions - in London, Sunnyvale, Mountain
View, San Francisco and soon in Paris. The people I met, the
Mozilla offices and places I have seen, have, in some ways, humbled
me about what the future can hold. They were all really great
experiences that I did not dream of.
A bit of stats: in three years I fixed approximately 300 bugs and
reported ~320 bugs (~210 are fixed already). I worked on the Web
Console (I still do), the Inspector, the Computed Style view (in
the really early days, in 2010), the Source Editor, the network
monitor (the backend for network logging which is shared with the
console), the about:home page introduced
in Firefox 4 and a bit on Panorama (the tab grouping feature
introduced in Firefox 4).
I look forward to continue to work on more cool projects and to
work with really great people! The people make Mozilla what it is
and they have been really great with me. For everything, big thanks
to my colleagues, managers and, actually, friends who work on tools
for the open web platform.
29 May 2013, 09:21
Today's Firefox Nightly
(May 29, 2013) no longer has the Error Console enabled by default.
It has been replaced by the Browser Console which shows all of the
same errors, warnings and messages as the Error Console and more:
network logging and
window.console API logging from
all content and chrome windows - including extensions! It also has
a better UI, you can filter messages, evaluate JS with chrome
privileges and inspect objects.
If you find missing messages, please file bugs as soon as possible in
the "Developer Tools: Console" component. Thank you!
The Browser Console shares the same code with the Web Console. This
means you will get all of the improvements we are working on - we
are gearing up for a console output UI
If you want to enable the Error Console you can change the
devtools.errorconsole.enabled option to
true from about:config.
Pro tip: in your Firefox chrome code (including
extensions) you can do:
The above code will output to the Browser Console if you have it
open - you can inspect objects, print stack traces
console.trace()) and do a bit of timing
Update: these changes should have no impact in
Thunderbird, XULRunner or any other applications. Currently the
changes are limited to hiding the Error Console menu item from
Firefox by default, and the Ctrl/Cmd-Shift-J keyboard
shortcut now opens the Browser Console instead of the Error
9 April 2013, 14:12
Today we just landed three new Web Console features you can play
with in tomorrow's Firefox
On a related note, Victor Porof also landed the new network monitor
which gives you a very nice UI for working with the log of network
requests and responses. The new tool uses the
Web Console actors we worked on for making the Web Console
remotable - both tools share the same network logging mechanism.
Whenever you are debugging a script in the page you can now
sure you select in which stackframe you want to evaluate your code
- just switch to the desired frame in the Debugger view. Until
today the Web Console locked up while debugging pages. For
technical details, see bug
This feature required a number of important changes. The Web
Console now uses only the
debugger API to access the content JS objects. With these
changes we are fixing a number of bugs reports by users.
New object inspector
The old object inspector popup has been replaced with the same
variables view from the debugger, allowing us to fix long standing
issues with the old inspector. This is not just pretty UI: you can
now filter/search through the properties by name and value, edit
property name and value, delete properties, and more. You can also
variables view: when you edit a value you can just write
$("foo") or whatever you wish.
With this change object inspection works slightly different: you
will notice that many of the methods and properties of DOM objects
show in the prototype of the objects you inspect. The switch to the
The new Browser Console
To enable the Browser Console make sure you set
true in about:config (Firefox restart is needed). Open
the Browser Console from the Web Developer > Browser
Console menu item.
The new Console is meant for browser and addon developers: you can
see all of window.console API calls, from all windows,
all script and style errors/warnings, and all network requests from
all over the browser and from addons.
We plan to replace the Error Console with the Browser Console as
soon as possible: the Error Console provides users with less
capabilities than the Browser Console, and it is not remotable. You
can currently connect to any Firefox Mobile, Firefox OS and Firefox
for desktop instance and see all of the logs in the Browser Console
from the remote instance.
Given the amount of logging happening we plan to support better
ways of filtering output. For example, we would like to allow
developers to filter messages by addon.
The screenshot shows the Browser Console with the new object
What is next
All of the three features are the outcome of a lot of work from the
entire team. Still, I want to thank Panagiotis Astithas and Jim Blandy for the
debugger-related work and reviews, and Victor for the variables
Download a Firefox nightly
build, play with the new features until you break them. :)
Please let us know if you have any comments and report any bugs you find!
10 October 2012, 08:49
Here is a summary of the improvements we have made to the Web
Console in the latest versions of Firefox. In the new
Firefox 16 release we have added the ability to
Security Policy warnings and errors. We are also highlighting
network requests that happen over HTTP on HTTPS pages (and
vice-versa), and we did more output performance fine-tuning.
In the new Firefox Beta we have moved the Web
Console UI into its own
<iframe> - which gives
us better flexibility for upcoming work we will do. We changed the
UI to match the developer tools theme and we made objects you pass
console.log() inspectable. For example, if you call
console.log(document) you can click
also received a number of improvements. Last, but not least, now
you can zoom in/out the text in the Web Console - just press
Ctrl-- / Ctrl-+. The default font size should
also match your system's font size settings.
In the new Firefox Aurora release we landed a big
chunk of work that makes the Web Console remotable - we now make
use of the Remote
Debugging Protocol. This means you will be soon able to connect
Web Console instances to your B2G, Fennec or other Firefox for
desktop browser instances. We currently lack UI to allow you to do
this, but we are working on it. This work also paves the way to a
Global Console that could replace the Error Console, some
At the end of September the developer tools team had a
meetup in London. There I had the chance to
demo the Web Console client connected to a B2G
In the above screenshot you can see the Web Console client running
in a local Firefox for desktop build while connected to a local
build of B2G
Desktop running Gaia. You can see network logging, object
inspection, network request/response information and script errors
coming from B2G.
To learn more about the Web Console remoting capabilities see
768096 and the
wiki page on MDN. To follow the progress
with B2G integration see bug
What is next? We are going to complete work on B2G
integration, improve the way Web Console output works, and we will
probably add a Global Console. We also plan to improve the user
experience of the object inspector and the network panel.
19 August 2012, 09:20
A quick post to point fellow mozillians and users of Ruby on Rails to a useful gem made by
a friend of mine, Dennis: BrowserID (Persona)
authentication support for Devise. Thank you Dennis for your