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

Inherits:
Cop
  • Object
show all
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/empty_case_condition.rb

Overview

This cop 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.'.freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AST::Sexp

#s

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens

Methods included from PathUtil

absolute?, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(case_node) ⇒ Object



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# File 'lib/rubocop/cop/style/empty_case_condition.rb', line 58

def autocorrect(case_node)
  when_branches = case_node.when_branches

  lambda do |corrector|
    correct_case_when(corrector, case_node, when_branches)
    correct_when_conditions(corrector, when_branches)
  end
end

#on_case(case_node) ⇒ Object



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# File 'lib/rubocop/cop/style/empty_case_condition.rb', line 44

def on_case(case_node)
  return if case_node.condition
  return if case_node.when_branches.any? do |when_branch|
    when_branch.each_descendant.any?(&:return_type?)
  end

  if (else_branch = case_node.else_branch)
    return if else_branch.return_type? ||
              else_branch.each_descendant.any?(&:return_type?)
  end

  add_offense(case_node, location: :keyword)
end