Am I the only one who thinks a lot of this is a little too specific on so many things? This thing reads like a list of things discovered while building an app, now they're making it gospel to know all these nuances. Knowing the trialing-comma thing, for example, is an I.E. only thing. What if you just don't code with trailing-commas to begin with because it doesn't look right, so you've never come across that? Anyway…
As an engineer whose recent focus has been front-end, I wish this was true.
The iOS7 rollout is what's been on my mind lately. That version of Mobile Safari had a number of new quirks/bugs which caused some significant usability issues on the site of a major automaker that I've been working on most of this year.
After poking at one of the biggest problems for two weeks, we eventually came to the conclusion that there was no fix available, and the choices were (a) live with the problem (b) entirely re-engineer some components just to accommodate iOS7, or (c) gracefully degrade for the newest version of what is likely the most significant mobile browser.
I've enjoyed watching and participating in a lot of the progress and excitement on the front-end over the last 10 years. But this development really depresses my enthusiasm. It was kindof understood years ago that, sure, for now we might have to make sure we knew the quirky minutia of each of the major 3-4 rendering engines, but the promise was the quirks would fade, browsers would converge on standards, we'd paper over whatever Microsoft couldn't/wouldn't manage to fix themselves, and eventually get on with the actual engineering.
Watching another major vendor introduce new quirky minutia in 2013 makes me wonder if front-end engineering will always mean that you'll have to fill up your head and your time with ephemeral, non-generalizable knowledge that will never really help you grow into a better problem solver.