So I find the post "debatable"...
Well I thought refactoring went all the way back to Forth.
I'm sure that with some language xyz it worked out very well for some project abc and that obviously disproves my whole point and you can move on...
I found writing large projects in Python - a language I was very familiar with, expert even - to become very difficult to extend aka maintain after a long time. My post should be seen in the bigger picture of the post I was following up about "Scaling My Server", and others I have written.
The original refactoring browser was in Smalltalk. Forth programmers don't go about that type of thing the same way as other language since the goal is really to write good "words" that express your program. It is more building a better language than traditional refactoring.
Of course, sweeping generalizations about static versus dynamic languages tend to fall flat.
Well, I think he has an interesting data-point, and makes some interesting points despite maybe making a somewhat incorrect generalization.
But even that generalization points to something I find interesting, which is that Python and JavaScript (maybe Ruby as well) possibly form a separate group with the characteristics he describes.
I also found the observation that Mock object testing doesn't seem to respond well to changes in the underlying code interesting.
It's that mix that makes it "debatable" ;-)
rspec-fire for example validates that the object you're mocking responds to the method name you've used, and takes the same number of arguments. It also does it conditionally based on whether the class in question has been loaded, so your unit tests can run in isolation, but when you run your full test suite it will catch any mocking errors.
Pretty handy!
> If you misspell a variable [...], you discover this at run time. Ouch.
CL-USER> (defun square (n) (* nn n)) ;; Ouch! nn isn't defined!
; in: DEFUN SQUARE ; (* NN N) ; ; caught WARNING: ; undefined variable: NN ; ; compilation unit finished ; Undefined variable: ; NN ; caught 1 WARNING condition SQUARE
Technically speaking, the more reflection a language provides, the less correct this becomes. Python code can dynamically inject local variables into stack frames, attributes into objects and so on in more or less silly and probably non-portable ways. So in the end, you end up with pragmatic correctness for mostly sane code. If that's enough for you and your project, go with it.
$ perl -Mstrict -E 'say $foo'
Global symbol "$foo" requires explicit package name at -e line 1.
$ cat err.py
def a():
print b
$ pylint -E err.py
************* Module err
E: 2,8:a: Undefined variable 'b'