Psych outputs a different file than it read in

deep_merge_and_output.rb

require 'yaml'
my_yaml = YAML::load(File.read('en.yml')).to_yaml

=begin
 1.9.3-p0 :002 > YAML::load(File.read('en.yml')).to_yaml
 => "---\nen:\n  refinery:\n    plugins:\n      lovelies:\n        title: Lovely Profiles\n    people:\n      admin:\n        lovelies:\n          actions:\n            create_new: Add New Lovely profile\n            reorder: Reorder Lovely profiles\n            reorder_done: Done Reordering Lovely profiles\n          records:\n            title: Lovely\n            sorry_no_results: Sorry! There are no results found.\n            no_items_yet: There are no Lovely profiles yet. Click \"Add New Lovely\n              profile\" to add one.\n          lovely:\n            view_live_html: View the lovely area live <br/><em>(opens in a new window)</em>\n            edit: Edit this lovely profile\n            delete: Remove this lovely profile forever\n      lovelies:\n        show:\n          other: Other Lovely profiles\n  activerecord:\n    attributes:\n      refinery/things/lovely:\n        name: Name\n        title: Title\n        photo: Photo\n        bio: Bio\n"
=end

# the problem is this: no_items_yet: There are no Lovely profiles yet. Click \"Add New Lovely\n              profile\" to add one.

# Note how after \"Add New Lovely there is a \n as is demonstrated in en_after.yml

File.open('en_after.yml', 'w+') {|f| f.puts my_yaml }

en.yml

en:
  refinery:
    plugins:
      lovelies:
        title: Lovely Profiles
    people:
      admin:
        lovelies:
          actions:
            create_new: Add New Lovely profile
            reorder: Reorder Lovely profiles
            reorder_done: Done Reordering Lovely profiles
          records:
            title: Lovely
            sorry_no_results: Sorry! There are no results found.
            no_items_yet: There are no Lovely profiles yet. Click "Add New Lovely profile" to add one.
          lovely:
            view_live_html: View the lovely area live <br/><em>(opens in a new window)</em>
            edit: Edit this lovely profile
            delete: Remove this lovely profile forever
      lovelies:
        show:
          other: Other Lovely profiles
  activerecord:
    attributes:
      'refinery/things/lovely':
        name: Name
        title: Title
        photo: Photo
        bio: Bio

en_after.yml

---
en:
  refinery:
    plugins:
      lovelies:
        title: Lovely Profiles
    people:
      admin:
        lovelies:
          actions:
            create_new: Add New Lovely profile
            reorder: Reorder Lovely profiles
            reorder_done: Done Reordering Lovely profiles
          records:
            title: Lovely
            sorry_no_results: Sorry! There are no results found.
            no_items_yet: There are no Lovely profiles yet. Click "Add New Lovely
              profile" to add one.
          lovely:
            view_live_html: View the lovely area live <br/><em>(opens in a new window)</em>
            edit: Edit this lovely profile
            delete: Remove this lovely profile forever
      lovelies:
        show:
          other: Other Lovely profiles
  activerecord:
    attributes:
      refinery/things/lovely:
        name: Name
        title: Title
        photo: Photo
        bio: Bio

I can't seem to get libyaml to stop wrapping that string. It's definitely a behavior of libyaml and not psych (the ruby wrapper). Is there a reason you need to prevent wrapping? Libyaml will roundtrip the data structures correctly. Even though a newline is added, when you read the YAML back in, the data will be exactly the same.

Here is an example test to show what I mean:

require 'psych'
require 'minitest/autorun'

class RoundTripTest < MiniTest::Unit::TestCase
  def test_load
    load_original = Psych.load_file 'en.yml'

    my_yaml = load_original.to_yaml

    # Make sure the dumped YAML is different than the file
    refute_equal my_yaml, File.read('en.yml')

    # Make sure the first load equals the second load
    assert_equal load_original, Psych.load(my_yaml)
  end
end

Note that even though the output yaml is different than the original file, the ruby data structures are exactly the same. I hope this was helpful. :(

Thanks Aaron! I'll have to live with "it's valid" :-)