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

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, RepeatedAttributeDiscount, RuboCop::AST::Sexp, RepeatedCsendDiscount, IteratingBlock
Inherits: Object
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

IteratingBlock - Included

KNOWN_ITERATING_METHODS

RepeatedAttributeDiscount - Included

VAR_SETTER_TO_GETTER

Class Method Summary

Instance Attribute Summary

RepeatedAttributeDiscount - Included

#discount_repeated_attributes?

Instance Method Summary

RepeatedAttributeDiscount - Included

#calculate_node, #evaluate_branch_nodes,
#initialize

Plug into the calculator.
#attribute_call?, #discount_repeated_attribute?,
#find_attributes

Returns the "known_attributes" for the node by walking the receiver tree If at any step the subdirectory does not exist, it is yielded with the associated key (method_name) If the node is not a series of (c)send calls with no arguments, then nil is yielded.
#root_node?,
#setter_to_getter

or nil if it is not a setter.
#update_repeated_attribute

RepeatedCsendDiscount - Included

#discount_for_repeated_csend?, #reset_on_lvasgn, #reset_repeated_csend

IteratingBlock - Included

#block_method_name

Returns the name of the method called with a block if node is a block node, or a block-pass node.
#iterating_block?

Returns nil if node is neither a block node or a block-pass node.
#iterating_method?

Returns true iff name is a known iterating type (e.g.

Constructor Details

.new(node) ⇒ AbcSizeCalculator

[ GitHub ] 

  


# 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)  
  

  [ GitHub ]


  

  


# 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



  

    #argument?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 127



def argument?(node)
  node.argument_type? && capturing_variable?(node.children.first)
end


  








  

    #assignment?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 86



def assignment?(node)
  return compound_assignment(node) if node.masgn_type? || node.shorthand_asgn?

  node.for_type? ||
    (node.respond_to?(:setter_method?) && node.setter_method?) ||
    simple_assignment?(node) ||
    argument?(node)
end


  








  

    #branch?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 123



def branch?(node)
  BRANCH_NODES.include?(node.type)
end


  








  

    #calculate  
  

  [ GitHub ]


  

  


# 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


  








  

    #calculate_node(node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 76



def calculate_node(node)
  @assignment += 1 if assignment?(node)

  if branch?(node)
    evaluate_branch_nodes(node)
  elsif condition?(node)
    evaluate_condition_node(node)
  end
end


  








  

    #capturing_variable?(name)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 119



def capturing_variable?(name)
  name && !name.start_with?('_')
end


  








  

    #compound_assignment(node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 95



def compound_assignment(node)
  # Methods setter cannot be detected for multiple assignments
  # and shorthand assigns, so we'll count them here instead
  children = node.masgn_type? ? node.children[0].children : node.children

  will_be_miscounted = children.count do |child|
    child.respond_to?(:setter_method?) && !child.setter_method?
  end
  @assignment += will_be_miscounted

  false
end


  








  

    #condition?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 131



def condition?(node)
  return false if iterating_block?(node) == false

  CONDITION_NODES.include?(node.type)
end


  








  

    #else_branch?(node)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# 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)  
  

  [ GitHub ]


  

  


# 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)  
  

  [ GitHub ]


  

  


# 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


  








  

    #simple_assignment?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 108



def simple_assignment?(node)
  if !node.equals_asgn?
    false
  elsif node.lvasgn_type?
    reset_on_lvasgn(node)
    capturing_variable?(node.children.first)
  else
    true
  end
end


  








  

    #visit_depth_last(node) {|node| ... }  (private)
  



  

    
  





  
Yields:


    
  
  • 
    (node)
  
    • 





  [ GitHub ]


  

  


# File 'lib/rubocop/cop/metrics/utils/abc_size_calculator.rb', line 71



def visit_depth_last(node, &block)
  node.each_child_node { |child| visit_depth_last(child, &block) }
  yield node
end