class RuboCop::Cop::Style::EmptyCaseCondition

end
puts ‘more’
else
puts ‘one’
when 1
puts ‘zero’
when 0
case n
# good: (the case condition node is not empty)
end
puts ‘neither is 0’
else
puts ‘y is 0’
elsif y == 0
puts ‘x is 0’
if x == 0
# good:
end
puts ‘neither is 0’
else
puts ‘y is 0’
when y == 0
puts ‘x is 0’
when x == 0
case
# bad:
@example
This cop checks for case statements with an empty condition.

def autocorrect(case_node) 

def autocorrect(case_node)
  lambda do |corrector|
    _cond_node, *when_nodes, _else_node = *case_node
    correct_case_whens(corrector, case_node, when_nodes)
    correct_multiple_alternative_whens(corrector, when_nodes)
  end
end

def correct_case_whens(corrector, case_node, when_nodes) 

def correct_case_whens(corrector, case_node, when_nodes)
  case_to_first_when =
    case_node.loc.keyword.join(when_nodes.first.loc.keyword)
  corrector.replace(case_to_first_when, 'if')
  when_nodes.drop(1).each do |when_node|
    corrector.replace(when_node.loc.keyword, 'elsif')
  end
end

def correct_multiple_alternative_whens(corrector, when_nodes)

correct `when x, y` to `if x || y`.
Since an if condition containing commas is not syntactically valid, we 
def correct_multiple_alternative_whens(corrector, when_nodes)
  when_nodes.each do |when_node|
    # In `when a; r` we have two children: [a, r].
    # In `when a, b, c; r` we have 4.
    # In `when a, b then r` we have 3.
    *children, _ = when_node.children
    next unless children.size > 1
    first = children.first
    last = children.last
    range = range_between(first.loc.expression.begin_pos,
                          last.loc.expression.end_pos)
    corrector.replace(range, children.map(&:source).join(' || '))
  end
end

def on_case(case_node) 

def on_case(case_node)
  condition_node = case_node.children.first
  add_offense(case_node, :keyword, MSG) if condition_node.nil?
end