Ehsan Akhgari is a programmer living in Toronto working for Mozilla. He has over 10 years of experience on browsers and the web platform and Firefox. Learn more about him here.

Identifying regressions when working on bugs

Many of the patches that we write are fixes to things that have broken as a result of a change, often known as regressions. An important aspect of a high quality release is for us to be able to identify and fix as many of these regressions as we can for each release, and this requires collaboration between people who file bugs, those who triage them, people who fix them, and of course the release managers.

Quantum Flow Engineering Newsletter #22

With around three weeks left in the development cycle for Firefox 57, everyone seems to be busy getting the last fixes in to shape up this long-awaited release. On the Quantum Flow project, we have kept up with the triage of the incoming bug reports that are tagged as [qf], and as we're getting closer to the beta uplift date, the realistic opportunity for fixing bugs is getting narrower, and as such the bar for prioritizing incoming bug reports as [qf:p1] keeps getting higher.

Quantum Flow Engineering Newsletter #21

We're now about mid-way through the Firefox 57 development cycle. The progress of Quantum Flow bugs has been steady, we now have 65 open [qf:p1] bugs at the time of this writing and 283 fixed bugs. There are still more bugs being flagged for triage constantly. I haven't really spoken much about the triage process lately and the reason is that it has been working as per usual and the output should be fairly visible to everyone through our dashboard.

Quantum Flow Engineering Newsletter #20

It is hard to believe that we've gotten to the twentieth of these newsletters. That also means that we're very quickly approaching the finish line for this sprint. We only have a bit more than five more weeks to go before Firefox 57 merges to beta. It may be a good time to start to think more carefully about what we pay attention to in the remaining time, both in terms of the risk of patches landing, and the opportunity cost of what we decide to put off until 58 and the releases after.

Quantum Flow Engineering Newsletter #19

As usual, I have some quick updates to share about what we've been up to on improving the performance of the browser in the past week or so. Let's first look at our progress on the Speedometer benchmark. Our performance goal for Firefox 57 was to get within 20% of Chrome's benchmark score on our Acer reference hardware on Win64. Those of you who watch the Firefox Health Dashboards every once in a while may have noticed that now we are well within that target:

Quantum Flow Engineering Newsletter #18

This has been a busy week. A lot of fixes have landed, setting up the Firefox 57 cycle for a good start. On the platform side, a notable change that will be in the upcoming Nightly is the fix for document.cookie using synchronous IPC. This super popular API call slows down various web pages today in Firefox, and starting from tomorrow, the affected pages should experience a great speedup. I have sometimes seen the slowdown caused by this one issue to amount to a second or more in some situations, thanks a lot to Amy and Josh for their hard work on this feature.