class RuboCop::Cop::Lint::LiteralInInterpolation

“result is #{10}”
@example
This cop checks for interpolated literals.

def on_dstr(node) 

def on_dstr(node)
  node.children.select { |n| n.type == :begin }.each do |begin_node|
    final_node = begin_node.children.last
    next unless final_node
    # handle strings like __FILE__
    return if special_string?(final_node)
    next unless LITERALS.include?(final_node.type)
    add_offense(final_node, :expression)
  end
end

def special_string?(node) 

def special_string?(node)
  node.type == :str && !node.loc.respond_to?(:begin)
end