[kaffeinecoma]

In a static language this would be flagged as an error. I assume something less than ideal happens in languages such as Ruby.

I once worked at a company where a very early piece of code had a typo "properites" instead of "properties". This misspelling became institutionalized, and was used throughout the codebase because it was deemed too expensive to fix. And this was with a static language (with good IDE refactoring support)!

[Wilya]

In ruby, and I think most dynamic languages, this type of typo is likely to raise an exception. It could hurt, but a simple test run is likely to discover it.

The way javascript (which is what is linked) handles this, as amirhhz described it, leads to silent errors which could turn out a lot worse.

[kaffeinecoma]

Yes, but it would raise the exception at run-time, and only when the particular path is taken.

[xxbondsxx]

There's actually no exception, it just returns "undefined" and the if statement fails. That's why it's such a deadly bug -- no exception, and path dependent. Combine that with the async nature of JS and it's going to be a long night tracking that one down

[p4lindromica]

There are ways to raise this sort of error even in static languages: objc_sendMessage comes to mind

[palish]

I'm confused as to why they couldn't simply:

  grep -R properites .

[kaffeinecoma]

The whole software infrastructure was a scary house of cards. They were afraid that there was unknown code that might be depending on it. For example RESTful services in other departments that were not under our immediate control.

[storborg]

Perhaps the same reason why "referer" has not been corrected to "referrer".

[kaffeinecoma]

Yes, it was exactly like that- lots of code had grown around the "bug", and it was not immediately obvious what other software had come to depend upon it. "Little hairs", as Joel might say.

[evanlong]

Obviously you have never worked on a code base with 1000s of developers. If you edit almost every file then basically everyone needs to stop writing new code while the change is made. Otherwise the merges others have to do is going to be a disaster.

[adambyrtek]

Honestly, do you really work on the same code base with "1000s of developers"? I find it really dubious.

[evanlong]

Yes. It's called Microsoft.

[adambyrtek]

Well, then problems with such process are pretty well documented[1]. For comparison, at Google global refactorings are pretty common and usually painless, there are even custom tools to support such changes (push them through code review, ensure no tests are broken etc.)

[1] http://moishelettvin.blogspot.com/2006/11/windows-shutdown-c...

[evanlong]

I know the Microsoft process all too painfully. RI,FI,RI,FI,RI,FI,RI,RC,RTM,Ship It,Repeat.

But as to the "usually painless" at Google. So when does that pain happen?

Can you take me through the following scenarios: change a variable name, change a base class name that lots of people extend from, file renames?

How do you go about refactoring? Do everything at once? Breaking it into pieces? Do file rename then variable and base class renames? Or smallest piece at a time?

Once the refactoring is complete how do you communicate to others the changes so when they merge the code in they don't get too messed up? Or worse undo something in the refactoring. (Also follow up is it better to do the big refactoring so there is the one big merge or a bunch of little refactorings and lots of little merges across the spectrum).

I guess the code change isn't the problem. It's making a big change and getting people on the same page is much harder. Especially when their are varying degrees of skill and experience on a project. And it's this stuff that is painful and leads to not wanting to do big refactorings at a lot of shops.

[chernevik]

Perhaps they were using . . . something other than *nix.

EDIT: Justly downvoted <strikeout>chastised</strikeout> for attempting humor without understanding.

[palish]

That command works nicely for me in Cygwin.

EDIT: Eh, apologies if this sounded like chastising -- I didn't mean to. As a developer who's been trapped in "Windows-mindset" for many years, I wanted to try to inspire other Windows devs to try to use *nix-based solutions even if their only option is Windows development. Cygwin is in a very good spot right now -- it's achieved so much acceptance that even the most hardened institutions now allow it to be installed.

[chernevik]

No snarkier than my remark, and less snarky than it might have been for being so much smarter.