Class: RuboCop::Cop::Metrics::Utils::AbcSizeCalculator

Inherits:
Object
  • Object
show all
Includes:
IteratingBlock, RepeatedAttributeDiscount, RepeatedCsendDiscount
Defined in:
lib/rubocop/cop/metrics/utils/abc_size_calculator.rb

Overview

ABC is .. a software size metric .. computed by counting the number of assignments, branches and conditions for a section of code. http://c2.com/cgi/wiki?AbcMetric

We separate the calculator from the cop so that the calculation, the formula itself, is easier to test.

Constant Summary

Constants included from IteratingBlock

IteratingBlock::KNOWN_ITERATING_METHODS

Class Method Summary collapse

Instance Method Summary collapse

Methods included from RepeatedCsendDiscount

#discount_for_repeated_csend?, #reset_on_lvasgn, #reset_repeated_csend

Methods included from IteratingBlock

#block_method_name, #iterating_block?, #iterating_method?

Methods included from RepeatedAttributeDiscount

#discount_repeated_attributes?

Constructor Details

#initialize(node) ⇒ AbcSizeCalculator

Returns a new instance of AbcSizeCalculator.



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# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 34

def initialize(node)
  @assignment = 0
  @branch = 0
  @condition = 0
  @node = node
  reset_repeated_csend
end

Class Method Details

.calculate(node, discount_repeated_attributes: false) ⇒ Object 



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# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 30

def self.calculate(node, discount_repeated_attributes: false)
  new(node, discount_repeated_attributes: discount_repeated_attributes).calculate
end

Instance Method Details

#calculate ⇒ Object 



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# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 42

def calculate
  visit_depth_last(@node) { |child| calculate_node(child) }

  [
    Math.sqrt((@assignment**2) + (@branch**2) + (@condition**2)).round(2),
    "<#{@assignment}, #{@branch}, #{@condition}>"
  ]
end

#else_branch?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 65

def else_branch?(node)
  %i[case if].include?(node.type) && node.else? && node.loc.else.is?('else')
end

#evaluate_branch_nodes(node) ⇒ Object 



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# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 51

def evaluate_branch_nodes(node)
  if node.comparison_method?
    @condition += 1
  else
    @branch += 1
    @condition += 1 if node.csend_type? && !discount_for_repeated_csend?(node)
  end
end

#evaluate_condition_node(node) ⇒ Object 



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# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 60

def evaluate_condition_node(node)
  @condition += 1 if else_branch?(node)
  @condition += 1
end