Class: RuboCop::Cop::Metrics::PerceivedComplexity

Inherits:

CyclomaticComplexity

• Object
• Base
• CyclomaticComplexity
• RuboCop::Cop::Metrics::PerceivedComplexity

Defined in:

lib/rubocop/cop/metrics/perceived_complexity.rb

Overview

Tries to produce a complexity score that's a measure of the complexity the reader experiences when looking at a method. For that reason it considers when nodes as something that doesn't add as much complexity as an if or a &&. Except if it's one of those special case/when constructs where there's no expression after case. Then the cop treats it as an if/elsif/elsif... and lets all the when nodes count. In contrast to the CyclomaticComplexity cop, this cop considers else nodes as adding complexity.

A case/in branch whose pattern is a simple literal (e.g. in 1, in "red", in 1..10) or a constant/type (e.g. in Integer) and has no guard is just as easy to read as a when branch, so it is discounted the same way. Branches with structural patterns (e.g. array, hash, or find patterns), bindings, alternatives, or a guard add the full complexity of a decision point.

Examples:

def example_1                   # 1
  if cond                       # 1
    case var                    # 2 (0.8 + 4 * 0.2, rounded)
    when 1 then func_one
    when 2 then func_two
    when 3 then func_three
    when 4..10 then func_other
    end
  else                          # 1
    do_something until a && b   # 2
  end                           # ===
end                             # 7 complexity points

def example_2                   # 1
  case color                    # 1 (3 * 0.2, rounded)
  in "red" then func_red
  in "blue" then func_blue
  in "green" then func_green
  end                           # ===
end                             # 2 complexity points

Constant Summary

MSG =

'Perceived complexity for `%<method>s` is too high. [%<complexity>d/%<max>d]'

COUNTED_NODES =

(
  CyclomaticComplexity::COUNTED_NODES - %i[when in_pattern] + %i[case case_match]
).freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source, #project_index

Method Summary

Methods included from RuboCop::Cop::MethodComplexity

#on_block, #on_def

Methods included from ExcludeLimit

cop_dir_for, #exclude_limit, read_limits

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_gem_version, #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