class RuboCop::Cop::Lint::Void

end
some_var
do_something
def some_method(some_var)
# good
@example
end
some_num * 10
do_something
def some_method
# good
@example
end
do_something
some_var
def some_method(some_var)
# 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 = expressions.drop_last(1) unless in_void_context?(node)
  expressions.each do |expr|
    check_void_op(expr)
    check_literal(expr)
    check_var(expr)
    check_self(expr)
    check_defined(expr)
  end
end

def check_defined(node) 

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

def check_literal(node) 

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

def check_self(node) 

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

def check_var(node) 

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

def check_void_op(node) 

def check_void_op(node)
  return unless node.send_type? && OPERATORS.include?(node.method_name)
  add_offense(node, :selector, format(OP_MSG, node.method_name))
end

def in_void_context?(node) 

def in_void_context?(node)
  parent = node.parent
  return false unless parent && parent.children.last == node
  VOID_CONTEXT_TYPES.include?(parent.type) && parent.void_context?
end

def on_begin(node) 

def on_begin(node)
  check_begin(node)
end