Testing Private Methods

Friday, March 09, 2007 by Nate Murray.

This probably isn't news to most of you, but it might help someone. Sometimes you want to test private methods. If you want you can just set the method to be public from within a #class_eval. Then call it in your test. For example:

def test_private_method
  product = products(:first) # grab our fixture
  product.class.class_eval do
    public :some_private_method
  end

  assert product.some_private_method
end

Labels: beginner, ruby, snippets

Directory Trees

Tuesday, March 06, 2007 by Nate Murray.

Below is a code snippet for putting directory tree into a data structure. Basically what I wanted was for each folder to be a hash with the key being the folder name and the value was an array of the files and folders it contains. For example: The folders:

       content/policy
       content/policy/privacy_policy.txt
       content/policy/about_us.txt
       content/policy/mean_policy
       content/policy/mean_policy/nice_people.txt
       content/policy/mean_policy/mean_people.txt
       content/index.txt
       content/content
       content/content/misc

Creates the structure:

      {"content"=>
         [{"content"=>[{"misc"=>[]}]},
           "index.txt",
          {"policy"=>
            ["about_us.txt",
            {"mean_policy"=>["mean_people.txt", "nice_people.txt"]},
             "privacy_policy.txt"]}]}

The recursive code snippet is posted below:

    def content_files_in_dir(dir, results = {}, opts = {})
      return nil unless File.exist?(dir)
      entries = Dir.entries(dir).delete_if { |f| f =~ /^\./ }

      key = File.basename(dir)
      values = []

      entries.each do |entry|
        full_entry = File.join(dir, entry)
        values << ( File.directory?(full_entry) ?
          content_files_in_dir(full_entry, results, opts) :
          entry )
      end
      { key => values }
    end

Labels: recursion, ruby, snippets

Using Parameters as Default Parameters

by Nate Murray.

I noticed something interesting about arguments in parameters today. You can actually use default parameters in data structures in other default parameters. For instance:

[nathan@nate ~]$ irb
>> def foo(arg1, arg2 = [arg1])
>>   puts arg1.inspect
>>   puts arg2.inspect
>> end
=> nil
>> foo 3
3
[3]
=> nil

Labels: interesting, ruby, snippets