test: add tests for Server model

spec/rails_helper.rb

@@ -9,6 +9,7 @@ require "factory_bot"
 require "timecop"
 require "database_cleaner"
 require "webmock/rspec"
+require "shoulda-matchers"
 
 DatabaseCleaner.allow_remote_database_url = true
 ActiveRecord::Base.logger = Logger.new("/dev/null")
@@ -16,8 +17,17 @@ ActiveRecord::Base.logger = Logger.new("/dev/null")
 Dir[File.expand_path("factories/*.rb", __dir__)].each { |f| require f }
 Dir[File.expand_path("helpers/**/*.rb", __dir__)].each { |f| require f }
 
+ActionMailer::Base.delivery_method = :test
+
 ActiveRecord::Migration.maintain_test_schema!
 
+Shoulda::Matchers.configure do |config|
+  config.integrate do |with|
+    with.test_framework :rspec
+    with.library :rails
+  end
+end
+
 RSpec.configure do |config|
   config.use_transactional_fixtures = true
   config.infer_spec_type_from_file_location!