Rails: Array#to_sentence

Documentation

Converts the array to comma-seperated sentence where the last element is joined by the connector word. Options:

• :connector: The word used to join the last element in arrays with two or more elements (default: "and")
  
• :skip_last_comma: Set to true to return "a, b and c" instead of "a, b, and c".

Usage
Array#to_sentence is perfect for joining information stored in an array that needs to be presented in a human readable format (e.g. an array of errors).

Test

require 'rubygems'
require 'active_support'
require 'test/unit'
require 'dust'

unit_tests do
  test "words are joined nicely" do
    expected = "one, two, and three"
    assert_equal expected, ['one', 'two', 'three'].to_sentence
  end
end