Fetch YARP AST for a method

yarp_ast.rb

require "yarp"

module YARPAST
  def yarp_ast
    ast =
      begin
        RubyVM::AbstractSyntaxTree.of(self, keep_script_lines: true)
      rescue ArgumentError
      end

    return unless ast
    lines = ast.script_lines
    source = lines[(ast.first_lineno - 1)..(ast.last_lineno - 1)]

    source[-1] = source[-1].byteslice(...ast.last_column)
    source[0] = source[0].byteslice(ast.first_column..)

    YARP.parse(source.join)
  end

  Method.include(self)
  UnboundMethod.include(self)
end

pp YARP::Location.method(:null).yarp_ast