You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: if.rb
    path of file: ./repos/opal/lib/opal/nodes
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require 'opal/nodes/base'
require 'opal/ast/matcher'

module Opal
  module Nodes
    class IfNode < Base
      handle :if

      children :test, :true_body, :false_body

      def compile
        if sh
    
      def simple?(body)
        case body
        when AST::Node
          case body.type
          when :return, :js_return, :break, :next, :redo, :retry
            false
          when :xstr
            XStringNode.single_line?(
              XStringNode.strip_empty_children(body.children)
            )
          else
            body.children.all? { |i| simple?(i) }
          end