Class: RuboCop::Cop::Style::EmptyCaseCondition

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/empty_case_condition.rb

Overview

Checks for case statements with an empty condition.

Examples:


# bad:
case
when x == 0
  puts 'x is 0'
when y == 0
  puts 'y is 0'
else
  puts 'neither is 0'
end

# good:
if x == 0
  puts 'x is 0'
elsif y == 0
  puts 'y is 0'
else
  puts 'neither is 0'
end

# good: (the case condition node is not empty)
case n
when 0
  puts 'zero'
when 1
  puts 'one'
else
  puts 'more'
end

Constant Summary collapse

MSG = 
'Do not use empty `case` condition, instead use an `if` expression.'
NOT_SUPPORTED_PARENT_TYPES = 
%i[return break next send csend].freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

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 ExcludeLimit

#exclude_limit

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

Instance Method Details

#on_case(case_node) ⇒ Object

rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity



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# File 'lib/rubocop/cop/style/empty_case_condition.rb', line 46

def on_case(case_node)
  if case_node.condition || NOT_SUPPORTED_PARENT_TYPES.include?(case_node.parent&.type)
    return
  end

  branch_bodies = [*case_node.when_branches.map(&:body), case_node.else_branch].compact

  return if branch_bodies.any? do |body|
    body.return_type? || body.each_descendant.any?(&:return_type?)
  end

  add_offense(case_node.loc.keyword) { |corrector| autocorrect(corrector, case_node) }
end