Class: RuboCop::Cop::Style::CaseLikeIf

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

Overview

Identifies places where if-elsif constructions can be replaced with case-when.

Examples:

MinBranchesCount: 3 (default)

# bad
if status == :active
  perform_action
elsif status == :inactive || status == :hibernating
  check_timeout
elsif status == :invalid
  report_invalid
else
  final_action
end

# good
case status
when :active
  perform_action
when :inactive, :hibernating
  check_timeout
when :invalid
  report_invalid
else
  final_action
end

MinBranchesCount: 4

# good
if status == :active
  perform_action
elsif status == :inactive || status == :hibernating
  check_timeout
elsif status == :invalid
  report_invalid
else
  final_action
end

Cop Safety Information:

  • This cop is unsafe. case statements use === for equality, so if the original conditional used a different equality operator, the behavior may be different.

Constant Summary collapse

MSG =
'Convert `if-elsif` to `case-when`.'

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, autocorrect_incompatible_with, badge, #begin_investigation, 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, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, 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_if(node) ⇒ Object



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# File 'lib/rubocop/cop/style/case_like_if.rb', line 57

def on_if(node)
  return unless should_check?(node)

  target = find_target(node.condition)
  return unless target

  conditions = []
  convertible = true

  branch_conditions(node).each do |branch_condition|
    return false if regexp_with_working_captures?(branch_condition)

    conditions << []
    convertible = collect_conditions(branch_condition, target, conditions.last)
    break unless convertible
  end

  return unless convertible

  add_offense(node) { |corrector| autocorrect(corrector, node) }
end