Add initial Conference model implementation

app/models/conference.rb

@@ -0,0 +1,16 @@
+class Conference < ActiveRecord::Base
+  validates :title, presence: true, uniqueness: true
+  validates :email, presence: true, format: {with: /\A[^@]+@[^@]+\z/}
+  validates :description, presence: true
+  validates :start_date, presence: true
+  validates :end_date, presence: true
+  validate :end_date_is_before_start_date
+
+  private
+
+  def end_date_is_before_start_date
+    if start_date.present? and end_date.present? and start_date > end_date
+      errors.add(:end_date, :cannot_be_before_start_date)
+    end
+  end
+end

db/migrate/20140810162730_create_conferences.rb

@@ -0,0 +1,13 @@
+class CreateConferences < ActiveRecord::Migration
+  def change
+    create_table :conferences do |t|
+      t.string :title, null: false
+      t.string :email, null: false
+      t.text :description, null: false
+      t.timestamp :start_date, null: false
+      t.timestamp :end_date, null: false
+
+      t.timestamps
+    end
+  end
+end

spec/factories/conferences.rb

@@ -0,0 +1,11 @@
+# Read about factories at https://github.com/thoughtbot/factory_girl
+
+FactoryGirl.define do
+  factory :conference do
+    title { |n| "Conference-#{n}"}
+    email
+    description 'MyText'
+    start_date '2014-07-29 21:29:13'
+    end_date '2014-07-31 21:29:13'
+  end
+end

spec/models/conference_spec.rb

@@ -0,0 +1,42 @@
+require 'rails_helper'
+
+RSpec.describe Conference, :type => :model do
+  describe 'title' do
+    it 'must not be blank' do
+      expect(build(:conference, title: '')).to have_error_on :title
+    end
+
+    it 'must be unique' do
+      create :conference, title: 'ExampleConf'
+      expect(build(:conference, title: 'ExampleConf')).to have_error_on :title
+    end
+  end
+
+  describe 'email' do
+    it 'must be present' do
+      expect(build(:conference, email: '')).to have_error_on :email
+    end
+
+    it 'can contain exatly one @' do
+      expect(build(:conference, email: 'test@@example.com')).to have_error_on :email
+      expect(build(:conference, email: 'test@example.com')).to_not have_error_on :email
+      expect(build(:conference, email: 'testexample.com')).to have_error_on :email
+    end
+  end
+
+  it 'is invalid without a description' do
+    expect(build(:conference, description: '')).to have_error_on :description
+  end
+
+  it 'is invalid without a start date' do
+    expect(build(:conference, start_date: nil)).to have_error_on :start_date
+  end
+
+  it 'is invalid without an end date' do
+    expect(build(:conference, end_date: nil)).to have_error_on :end_date
+  end
+
+  it 'is invalid when the end date is before the start date' do
+    expect(build(:conference, start_date: '2014-07-29 21:29:13', end_date: '2014-07-28 01:00:00')).to have_error_on :end_date
+  end
+end