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

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.

Examples:


def each_child_node(*types)               # count begins: 1
  unless block_given?                     # unless: +1
    return to_enum(__method__, *types)
  end

  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 in_pattern 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

#on_block, #on_def

Methods included from ExcludeLimit

#exclude_limit

Methods included from Utils::RepeatedCsendDiscount

#discount_for_repeated_csend?, #reset_on_lvasgn, #reset_repeated_csend

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #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