class RuboCop::Cop::Metrics::CyclomaticComplexity
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. Blocks that are calls to builtin iteration methods (e.g. ‘ary.map{…}) also add one, others are ignored.
def each_child_node(*types) # count begins: 1 unless block_given? # unless: +1 return to_enum(__method__, *types) children.each do |child| # each{}: +1 next unless child.is_a?(Node) # unless: +1 yield child if types.empty? || # if: +1, ||: +1 types.include?(child.type) end self end # total: 6
Constants
- COUNTED_NODES
- MSG
Private Instance Methods
complexity_score_for(node)
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# File lib/rubocop/cop/metrics/cyclomatic_complexity.rb, line 42 def complexity_score_for(node) return 0 if iterating_block?(node) == false return 0 if node.csend_type? && discount_for_repeated_csend?(node) 1 end
count_block?(block)
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# File lib/rubocop/cop/metrics/cyclomatic_complexity.rb, line 49 def count_block?(block) KNOWN_ITERATING_METHODS.include? block.method_name end