class RuboCop::Cop::Lint::Void

end
some_var
do_something
def some_method
# good
@example
end
some_num * 10
do_something
def some_method
# good
@example
end
do_something
some_var
def some_method
# bad
@example
end
do_something
some_num * 10
def some_method
# bad
@example
in void context.
This cop checks for operators, variables and literals used

def check_begin(node) 

def check_begin(node)
  expressions = *node
  expressions.drop_last(1).each do |expr|
    check_for_void_op(expr)
    check_for_literal(expr)
    check_for_var(expr)
    check_for_self(expr)
    check_for_defined(expr)
  end
end

def check_for_defined(node) 

def check_for_defined(node)
  return unless node.defined_type?
  add_offense(node, :expression, format(DEFINED_MSG, node.source))
end

def check_for_literal(node) 

def check_for_literal(node)
  return if !node.literal? || node.xstr_type?
  add_offense(node, :expression, format(LIT_MSG, node.source))
end

def check_for_self(node) 

def check_for_self(node)
  return unless node.self_type?
  add_offense(node, :expression, SELF_MSG)
end

def check_for_var(node) 

def check_for_var(node)
  return unless node.variable? || node.const_type?
  add_offense(node, :name, format(VAR_MSG, node.loc.name.source))
end

def check_for_void_op(node) 

def check_for_void_op(node)
  return unless node.send_type? && node.loc.selector
  op = node.loc.selector.source
  add_offense(node, :selector, format(OP_MSG, op)) if OPS.include?(op)
end

def on_begin(node) 

def on_begin(node)
  check_begin(node)
end

def on_kwbegin(node) 

def on_kwbegin(node)
  check_begin(node)
end