Class: RuboCop::Cop::Metrics::CyclomaticComplexity

Inherits:
Base
  • Object
show all
Includes:
RuboCop::Cop::MethodComplexity, Utils::IteratingBlock
Defined in:
lib/rubocop/cop/metrics/cyclomatic_complexity.rb

Overview

This cop 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

Direct Known Subclasses

PerceivedComplexity

Constant Summary collapse

MSG =
'Cyclomatic complexity for %<method>s is too high. ' \
'[%<complexity>d/%<max>d]'
COUNTED_NODES =
%i[if while until for csend block block_pass
rescue when and or or_asgn and_asgn].freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Method Summary

Methods included from RuboCop::Cop::MethodComplexity

included, #on_block, #on_def

Methods included from Utils::RepeatedCsendDiscount

#discount_for_repeated_csend?, #reset_on_lvasgn, #reset_repeated_csend

Methods included from IgnoredMethods

#ignored_method?, #ignored_methods, included

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base