Static code analysis

On the way to being a great programmer, everyone hits the same roadblock. Code Smells. One of the tools I have started using to help me recognize and locate code smells is “Static Code Analysis”.

Static code analysis is the process of running a program that instead of running your code, looks at how it was written. Though there are many of these tools out there, the two I’ve become reliant on are Reek and Pelusa.

Reek

Reek is the older of the two tools and provides a good foundation for programmers to get started with.

threebythree_implementations/brute_force_implementation.rb -- 5 warnings:
  TicTacToe::BruteForceImplementation#block_fork! has approx 7 statements (LongMethod)
  TicTacToe::BruteForceImplementation#corner_from_index has approx 6 statements (LongMethod)
  TicTacToe::BruteForceImplementation#each_position calls Board::SIZE.times twice (Duplication)
  TicTacToe::BruteForceImplementation#each_position contains iterators nested 2 deep (NestedIterators)
  TicTacToe::BruteForceImplementation#each_position doesn't depend on instance state (LowCohesion)

Reek looks at ones code, and provides a quick summary for whats wrong. The best part of reek, is its Wiki.
There one can get detailed descriptions of the code smells it finds, how suggestions how how to fix them.

Pelusa

Pelusa is a relatively new comer to the SCA tools and definitely not for the faint of heart. Based on this blog post Pelusa is a harsh grader.

class GameTree
    ✿ Is below 50 lines ✗
  This class has 63 lines.
    ✿ Uses less than 3 ivars ✗
  This class uses 5 instance variables: @evaluator, @state, @depth, @alpha, @beta.
    ✿ Respects Demeter law ✗
  There are 1 Demeter law violations in lines 123.
    ✿ Doesn't use more than one indentation level inside methods ✗
  There's too much indentation in lines 138, 157.
    ✿ Doesn't use else clauses ✓
    ✿ Doesn't use getters, setters or properties ✓
    ✿ Doesn't mix array instance variables with others ✓
    ✿ Uses descriptive names ✓
    ✿ Methods have short argument lists ✗
  Methods with more than 3 arguments: initialize
    ✿ Doesn't use eval statement ✓

As you can see, Pelusa goes the extra step to make sure your code is following the very best OO design patterns. Getting a perfect score may be hard, but if done, your code will thank you.

As one grows as a programmer, they’ll probably find that SCA tools become less useful as they can spots smells easier. But for new programmers trying to up their game, I can’t suggest them enough.