Add new methods

lib/stripe_mock/request_handlers/subscriptions.rb

@@ -102,7 +102,7 @@ def create_subscription(route, method_url, params, headers)
           customer[:default_source] = new_card[:id]
         end
 
-        allowed_params = %w(customer application_fee_percent coupon items metadata plan quantity source tax_percent trial_end trial_period_days current_period_start created prorate billing_cycle_anchor billing days_until_due idempotency_key enable_incomplete_payments cancel_at_period_end default_tax_rates payment_behavior pending_invoice_item_interval)
+        allowed_params = %w(customer application_fee_percent coupon items metadata plan quantity source tax_percent trial_end trial_period_days current_period_start created prorate billing_cycle_anchor billing days_until_due idempotency_key enable_incomplete_payments cancel_at_period_end default_tax_rates payment_behavior pending_invoice_item_interval default_payment_method expand)
         unknown_params = params.keys - allowed_params.map(&:to_sym)
         if unknown_params.length > 0
           raise Stripe::InvalidRequestError.new("Received unknown parameter: #{unknown_params.join}", unknown_params.first.to_s, http_status: 400)

lib/stripe_mock/test_strategies/base.rb

@@ -41,6 +41,17 @@ def create_plan_params(params={})
         }.merge(params)
       end
 
+      def create_payment_method(params={})
+        Stripe::PaymentMethod.create(params)
+      end
+
+      def create_customer(params={})
+        Stripe::Customer.create(params)
+      end
+
+      def create_subscription(params={})
+        Stripe::Subscription.create(params)
+      end
 
       def list_subscriptions(limit)
         Stripe::Subscription.list(limit: limit)