gsub_file_spec.rb

require 'fileutils'
require 'rspec'

describe 'regex_gsub' do

  before(:each) do
    @content = "Rails::Initializer.run do |config|\nend"
  end

  it 'should match against a string' do
    check_content(@content)
  end

  it 'should match when read from a file' do
    file_name = 'temp_gsub_file'
    File.open(file_name, 'wb') { |file| file.write(@content) }
    content_from_file = File.read(file_name)
    FileUtils.rm_f(file_name)
    check_content(content_from_file)
  end

  def check_content(content)
    data = "config.gem 'torquebox', :version => '2.2.0'"
    sentinel = 'Rails::Initializer.run do |config|'
    regexp = /(#{Regexp.escape(sentinel)})/mi
    replaced_content = content.gsub(regexp) do |match|
      "#{match}\n  " << data
    end
    replaced_content.should include('torquebox')
  end
end

output

bbrowning@bbrowning-mbp:~/tmp$ jruby -v
jruby 1.7.0.RC1 (1.9.3p203) 2012-09-25 df7874f on Java HotSpot(TM) 64-Bit Server VM 1.6.0_35-b10-428-10M3811 [darwin-x86_64]
bbrowning@bbrowning-mbp:~/tmp$ jruby --1.8 -S rspec gsub_file_spec.rb 
..

Finished in 0.041 seconds
2 examples, 0 failures
bbrowning@bbrowning-mbp:~/tmp$ jruby --1.9 -S rspec gsub_file_spec.rb 
.F

Failures:

  1) regex_gsub should match when read from a file
     Failure/Error: replaced_content.should include('torquebox')
       expected "Rails::Initializer.run do |config|\nend" to include "torquebox"
       Diff:
       @@ -1,2 +1,3 @@
       -torquebox
       +Rails::Initializer.run do |config|
       +end
     # ./gsub_file_spec.rb:29:in `check_content'
     # ./gsub_file_spec.rb:19:in `(root)'

Finished in 0.081 seconds
2 examples, 1 failure

Failed examples:

rspec ./gsub_file_spec.rb:14 # regex_gsub should match when read from a file
bbrowning@bbrowning-mbp:~/tmp$