Ruby: require vs require_relative - best practice to workaround running in both Ruby <1>=1.9.2

Question

What is the best practice if I want to require a relative file in Ruby and I want it to work in both 1.8.x and >=1.9.2?

I see a few options:

Answer 1

$LOAD_PATH << '.'

$LOAD_PATH << File.dirname(__FILE__)

It's not a good security habit: why should you expose your whole directory?

require './path/to/file'

This doesn't work if RUBY_VERSION < 1.9.2

use weird constructions such as

require File.join(File.dirname(__FILE__), 'path/to/file')

Even weirder construction:

require File.join(File.expand_path(File.dirname(__FILE__)), 'path/to/file')

Use backports gem - it's kind of heavy, it requires rubygems infrastructure and includes tons of other workarounds, while I just want require to work with relative files.

You have already answered why these are not the best options.

check if RUBY_VERSION < 1.9.2, then define require_relative as require, use require_relative everywhere where it's needed afterwards

check if require_relative already exists, if it does, try to proceed as in previous case

This may work, but there's safer and quicker way: to deal with the LoadError exception:

begin
  # require statements for 1.9.2 and above, such as:
  require "./path/to/file"
  # or
  require_local "path/to/file"
rescue LoadError
  # require statements other versions:
  require "path/to/file"
end