added tests and so on

spec/models/supporter_spec.rb

@@ -0,0 +1,7 @@
+require 'rails_helper'
+
+describe Supporter do
+  it { is_expected.to validate_presence_of(:email) }
+  it { is_expected.to validate_uniqueness_of(:email) }
+  it { is_expected.to validate_presence_of(:support) }
+end

spec/rails_helper.rb

@@ -0,0 +1,25 @@
+# This file is copied to spec/ when you run 'rails generate rspec:install'
+ENV['RAILS_ENV'] ||= 'test'
+require File.expand_path('../../config/environment', __FILE__)
+# Prevent database truncation if the environment is production
+abort('The Rails environment is running in production mode!') if Rails.env.production?
+require 'spec_helper'
+require 'rspec/rails'
+# Add additional requires below this line. Rails is not loaded until this point!
+
+# Requires supporting ruby files with custom matchers and macros, etc, in
+# spec/support/ and its subdirectories. Files matching `spec/**/*_spec.rb` are
+# run as spec files by default. This means that files in spec/support that end
+# in _spec.rb will both be required and run as specs, causing the specs to be
+# run twice. It is recommended that you do not name files matching this glob to
+# end with _spec.rb. You can configure this pattern with the --pattern
+# option on the command line or in ~/.rspec, .rspec or `.rspec-local`.
+#
+# The following line is provided for convenience purposes. It has the downside
+# of increasing the boot-up time by auto-requiring all files in the support
+# directory. Alternatively, in the individual `*_spec.rb` files, manually
+# require only the support files necessary.
+#
+# Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }
+
+RSpec.configure(&:infer_spec_type_from_file_location!)

spec/spec_helper.rb

@@ -0,0 +1,47 @@
+# This file is copied to spec/ when you run 'rails generate rspec:install'
+ENV['RAILS_ENV'] ||= 'test'
+require File.expand_path('../../config/environment', __FILE__)
+
+require 'rspec/rails'
+require 'mongoid-rspec'
+
+Mongo::Logger.logger.level = Logger::WARN # Set log level to DEBUG to see everything
+
+Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }
+
+# Require the gems listed in Gemfile, including any gems
+# you've limited to :test, :development, or :production.
+Bundler.require(*Rails.groups)
+
+RSpec.configure do |config|
+  config.include Mongoid::Matchers, type: :model
+
+  # rspec-expectations config goes here. You can use an alternate
+  # assertion/expectation library such as wrong or the stdlib/minitest
+  # assertions if you prefer.
+  config.expect_with :rspec do |expectations|
+    # This option will default to `true` in RSpec 4. It makes the `description`
+    # and `failure_message` of custom matchers include text for helper methods
+    # defined using `chain`, e.g.:
+    #     be_bigger_than(2).and_smaller_than(4).description
+    #     # => "be bigger than 2 and smaller than 4"
+    # ...rather than:
+    #     # => "be bigger than 2"
+    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
+  end
+
+  # rspec-mocks config goes here. You can use an alternate test double
+  # library (such as bogus or mocha) by changing the `mock_with` option here.
+  config.mock_with :rspec do |mocks|
+    # Prevents you from mocking or stubbing a method that does not exist on
+    # a real object. This is generally recommended, and will default to
+    # `true` in RSpec 4.
+    mocks.verify_partial_doubles = true
+  end
+
+  config.order = :random
+
+  config.after(:each) do
+    Mongoid.purge!
+  end
+end