Class: Reek::Smells::ControlCouple

Control Coupling occurs when a method or block checks the value of a parameter in order to decide which execution path to take. The offending parameter is often called a Control Couple.

A simple example would be the quoted parameter in the following method:

 def write(quoted)
   if quoted
     write_quoted(@value)
   else
     puts @value
   end
 end

Control Coupling is a kind of duplication, because the calling method already knows which path should be taken.

Control Coupling reduces the code‘s flexibility by creating a dependency between the caller and callee: any change to the possible values of the controlling parameter must be reflected on both sides of the call.

A Control Couple also reveals a loss of simplicity: the called method probably has more than one responsibility, because it includes at least two different code paths.

Methods

default_config examine_context new

Public Class methods

default_config()

[Source]

# File lib/reek/smells/control_couple.rb, line 42
      def self.default_config
        super.adopt(EXCLUDE_KEY => ['initialize'])
      end

new(config = ControlCouple.default_config)

[Source]

# File lib/reek/smells/control_couple.rb, line 46
      def initialize(config = ControlCouple.default_config)
        super
      end

Public Instance methods

examine_context(cond)

Checks whether the given conditional statement relies on a control couple. Remembers any smells found.

[Source]

# File lib/reek/smells/control_couple.rb, line 54
      def examine_context(cond)
        return unless cond.tests_a_parameter?
        found(cond, "is controlled by argument #{SexpFormatter.format(cond.if_expr)}")
      end