Contents

# encoding: utf-8

module Rubocop
  module Cop
    module Style
      # This cop checks that the cyclomatic complexity of methods is not higher
      # than the configured maximum. The cyclomatic complexity is the number of
      # linearly independent paths through a method. The algorithm counts
      # decision points and adds one.
      #
      # An if statement (or unless or ?:) increases the complexity by one. An
      # else branch does not, since it doesn't add a decision point. The &&
      # operator (or keyword and) can be converted to a nested if statement,
      # and ||/or is shorthand for a sequence of ifs, so they also add one.
      # Loops can be said to have an exit condition, so they add one.
      class CyclomaticComplexity < Cop
        include CheckMethods
        include ConfigurableMax

        MSG = 'Cyclomatic complexity for %s is too high. [%d/%d]'
        DECISION_POINT_NODES = [:if, :while, :until, :for, :rescue, :when,
                                :and, :or]

        private

        def check(node, method_name, *_)
          complexity = 1
          on_node(DECISION_POINT_NODES, node) { complexity += 1 }

          max = cop_config['Max']
          if complexity > max
            add_offence(node, :keyword,
                        sprintf(MSG, method_name, complexity, max)) do
              self.max = complexity
            end
          end
        end
      end
    end
  end
end

Version data entries

4 entries across 4 versions & 1 rubygems

Version	Path
rubocop-0.18.1	lib/rubocop/cop/style/cyclomatic_complexity.rb
rubocop-0.18.0	lib/rubocop/cop/style/cyclomatic_complexity.rb
rubocop-0.17.0	lib/rubocop/cop/style/cyclomatic_complexity.rb
rubocop-0.16.0	lib/rubocop/cop/style/cyclomatic_complexity.rb