class RuboCop::Cop::Metrics::Utils::AbcSizeCalculator
> ABC is .. a software size metric .. computed by counting the number > of assignments, branches and conditions for a section of code. > c2.com/cgi/wiki?AbcMetric
We separate the calculator from the cop so that the calculation, the formula itself, is easier to test.
Constants
- ARGUMENT_TYPES
TODO: move to rubocop-ast
- BRANCH_NODES
> Branch – an explicit forward program branch out of scope – a > function call, class method call .. > c2.com/cgi/wiki?AbcMetric
- CONDITION_NODES
> Condition – a logical/Boolean test, == != <= >= < > else case > default try catch ? and unary conditionals. > c2.com/cgi/wiki?AbcMetric
Public Class Methods
calculate(node, discount_repeated_attributes: false)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 28 def self.calculate(node, discount_repeated_attributes: false) new(node, discount_repeated_attributes: discount_repeated_attributes).calculate end
new(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 37 def initialize(node) @assignment = 0 @branch = 0 @condition = 0 @node = node reset_repeated_csend end
Public Instance Methods
calculate()
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 45 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)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 68 def else_branch?(node) %i[case if].include?(node.type) && node.else? && node.loc.else.is?('else') end
evaluate_branch_nodes(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 54 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)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 63 def evaluate_condition_node(node) @condition += 1 if else_branch?(node) @condition += 1 end
Private Instance Methods
argument?(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 131 def argument?(node) ARGUMENT_TYPES.include?(node.type) && capturing_variable?(node.children.first) end
assignment?(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 89 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)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 127 def branch?(node) BRANCH_NODES.include?(node.type) end
calculate_node(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 79 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)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 122 def capturing_variable?(name) # TODO: Remove `Symbol#to_s` after supporting only Ruby >= 2.7. name && !name.to_s.start_with?('_') end
compound_assignment(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 98 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)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 135 def condition?(node) return false if iterating_block?(node) == false CONDITION_NODES.include?(node.type) end
simple_assignment?(node)
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 111 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| ... }
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# File lib/rubocop/cop/metrics/utils/abc_size_calculator.rb, line 74 def visit_depth_last(node, &block) node.each_child_node { |child| visit_depth_last(child, &block) } yield node end