Refactoring

Notes from Industrial Logic course

Extract example

Original code

def printOwing(amount):
    printBanner()
    print "name: %s" % name
    print "amount: %f" % amount
    
def printLateNotice(amount):
    printBanner()
    print "name: %s" % name
    print "amount: %f" % amount

Refactored

def printOwing(amount):
    printBanner()
    printDetails()
    
def printLateNotice(amount):
    printBanner()
    printDetails()

def printDetails(amount):
    print "name: %s" % name
    print "amount: %f" % amount

Unlocking the Awesome Power of Refactoring

by J. B. Rainsberger tech excellence talk

Deliberate practice, Learned Helplessness.

Nanosteps –> Microsteps –> Moves Repetition –> Ease –> Chunking (autonomic, subconscious, higher order thinking) –> Confidence –> Courage

Pattern: Item –> Collection (ex function arg)

1. add extra arg f(x) --> f(x, xs: List).
2. modifiy calls of f(x) in the code base to use new signature.
3. modify f(x) to use xs instead of x.
4. verify that the behaviour of f() is the same.
5. remove x so that we are left with f(xs).

Start practicing now: 30min refactoring at the end of a day or even week. Throw the changes away.

Practice is not performance!

“Cleaning the kitchen as you cook”.