Nil Check

Introduction

A NilCheck is a type check. Failures of NilCheck violate the "tell, don't ask" principle. Additionally to that, type checks often mask bigger problems in your source code like not using OOP and / or polymorphism when you should.

Example

Given

class Klass
  def nil_checker(argument)
    if argument.nil?
      puts "argument isn't nil!"
    end
  end
end

reek would emit the following warning:

test.rb -- 1 warning:
  [3]:Klass#nil_checker performs a nil-check. (NilCheck)

Current Support in Reek

NilCheck reports use of

• .nil? method
• == and === operators when checking vs. nil
• case statements that use syntax like when nil

Configuration

Nil Check offers the Basic Smell Options.