Thoughtworks Brazil, Code Quality

Ola.  

You’re  making  me    refactor.  

You  won’t  like  me  when  I  refactor  

Refactoring?  

ThoughtWorks  

a  change  made  to  the  internal  structure  of  so=ware  to  make  it  easier  to  understand  and  cheaper  

to  modify  without  changing  its  observable  behavior  

 Don't  touch  anything  that  doesn't  have  coverage.  

Otherwise,  you're  not  refactoring;  you're  just  changing  shit  

ThoughtWorks  

a  change  made  to  the  internal  structure  of  so=ware  to  make  it  

easier  to  understand  and  cheaper  to  modify  without  changing  its  observable  behavior  

SomeHmes  it  just  feels  right.  

Step  1:  Measure  the  

toxicity.  

Smells  in  the  code  

CyclomaHc  Complexity  

5  to  7  is  decent  for  most  ruby  code  

Saikuro  

Assignments,  Branches,  Calls    with  Flog  

Watch  for  scores  greater  than  40  

Flog  

DuplicaHon  with  Flay  

Watch  for  scores  greater  than  30  

Control  Couples  and  more    with  Reek  

Simulated  Polymorphism  Feature  Envy  UHlity  Methods  

LinHng  with  Dust/Nitpick  

JSLint  for  Ruby  

Common  smells    in  Ruby    

PrimiHve  Obsession  

Feature  Envy  

Meta-­‐programming  

Keep  it  simple.    Keep  it  declaraHve  

Toxicity  is  more  than  code  smells  

“The  real  problem  I  have  with  the  CK  suite  and  similar  metrics  is  that  they  only  measure  a  single  module  (or  class  in  this  case).    I  claim  that  the  quality  of  the  design  of  a  system  is  not  something  that  can  be  determined  by  looking  at  individual  classes.    It  is  conceivable  that  every  class  in  a  system  could  be  considered  reasonable  by  whatever  single-­‐class  metrics  are  being  used,  but  the  overall  design  is  considered  bad.”  

hDp://www.cs.auckland.ac.nz/~ewan/  

Ewan  Tempero:  A  Research  Agenda  

DEPENDENCY  

Tangles  

Step  2:  Make  it  visible  

Treemaps  (Max  CC)  

hbp://mbostock.github.com/protovis/  

Treemaps  

Dependency  matrix  

Step  3:  Agree  on  the  fix  

Step  4:      Go  fix  it  

Obrigado