ActiveModel lint tests for rspec

active_model_lint.rb

# put the file into spec/support
shared_examples_for "ActiveModel" do
  include ActiveModel::Lint::Tests

  # to_s is to support ruby-1.9
  ActiveModel::Lint::Tests.public_instance_methods.map{|m| m.to_s}.grep(/^test/).each do |m|
    example m.gsub('_',' ') do
      send m
    end
  end

  def model
    subject
  end
end

example_spec.rb

# implicit subject
describe MyLooksLikeModelClass do
  it_behaves_like "ActiveModel"
end

# explicit subject
describe "my looks like model class" do
  subject { MyLooksLikeModelClass.new }
  it_behaves_like "ActiveModel"
end