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