school.rb

# Implementing http://beust.com/weblog/2013/02/13/coding-challenge-light-edition in Ruby
# Contract for eql? and hash as per: http://stackoverflow.com/questions/2328685/how-to-make-object-instance-a-hash-key-in-ruby
class School
  attr_accessor :name, :nickname

  def initialize(name, nickname)
    self.name = name
    self.nickname = nickname
  end

  def eql?(other)
    self.name == other.name || self.nickname == other.nickname
  end

  def hash()
    [self.name, self.nickname].hash
  end
end

school_test.rb

require "test_helper"

class SchoolTest < ActiveSupport::TestCase
  def setup
    @school = School.new("James Madison University", "JMU" )
    @identical_school = School.new("James Madison University", "JMU" )
    @different_name = School.new("James Madison", "JMU")
    @different_nick = School.new("James Madison University", "Dukes" )
    @different_school =  School.new("University of Virginia", "UVA" )
  end

  test "equality" do
    assert @school.eql?(@identical_school)
    assert @school.eql?(@different_name)
    assert @school.eql?(@different_nick)
    refute @school.eql?(@different_school)
  end

  test "Hash" do
    assert_equal Fixnum, @school.hash.class
    assert_equal @school.hash, @identical_school.hash
  end
end