Testing custom ActiveRecord validators with rspec and with_model

excitement_validator.rb

class ExcitementValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    unless value =~ /.*!/
      record.errors.add attribute, (options[:message] || "must end with an exclamation point")
    end
  end
end

excitement_validator_spec.rb

require 'spec_helper'

describe ExcitementValidator do
  with_model :post do
    table do |t|
      t.string :title
    end

    model do
      validates :title, excitement: true
    end
  end

  it "should be valid with an excited title" do
    Post.new(title: 'My amazing day!').should be_valid
  end

  it "should be invalid with an unexcited title" do
    Post.new(title: 'My lousy day.').should_not be_valid
  end
end