stripe service can create subscriptions

app/services/discourse_donations/stripe.rb

@@ -23,6 +23,18 @@ module DiscourseDonations
       @charge
     end
 
+    def subscribe(email, opts)
+      customer = ::Stripe::Customer.create(
+        email: email,
+        source: opts[:stripeToken]
+      )
+      @subscription = ::Stripe::Subscription.create(
+        customer: customer.id,
+        plan: opts[:plan]
+      )
+      @subscription
+    end
+
     def successful?
       @charge[:paid]
     end

spec/services/discourse_donations/stripe_spec.rb

@@ -6,7 +6,6 @@ module DiscourseDonations
     before { SiteSetting.stubs(:discourse_donations_secret_key).returns('secret-key-yo') }
 
     let(:stripe_options) { { description: 'hi there', currency: 'AUD' } }
-    let(:params) { { email: email, stripeToken: 'stripe-token', amount: '1234', other: 'redundant param' } }
     let(:email) { 'ray-zintoast@example.com' }
     let(:customer) { stub(id: 1) }
     let!(:subject) { described_class.new('secret-key-yo', stripe_options) }
@@ -15,6 +14,25 @@ module DiscourseDonations
       expect(::Stripe.api_key).to eq 'secret-key-yo'
     end
 
+    describe 'subscribe' do
+      let(:params) { { email: email, stripeToken: 'stripe-token', plan: 'subscription-plan-1234', other: 'redundant param' } }
+
+      it 'creates a customer and a subscription' do
+        ::Stripe::Customer.expects(:create).with(
+          email: email,
+          source: 'stripe-token'
+        ).returns(customer)
+        ::Stripe::Subscription.expects(:create).with(
+          customer: customer.id,
+          plan: params[:plan]
+        )
+        subject.subscribe(email, params)
+      end
+    end
+
+    describe 'charge' do
+      let(:params) { { email: email, stripeToken: 'stripe-token', amount: '1234', other: 'redundant param' } }
+
       it 'creates a customer and charges them an amount' do
         ::Stripe::Customer.expects(:create).with(
           email: email,
@@ -33,8 +51,10 @@ module DiscourseDonations
         )
         subject.charge(email, params)
       end
+    end
 
     describe '.successful?' do
+      let(:params) { { email: email, stripeToken: 'stripe-token', amount: '1234', other: 'redundant param' } }
       let(:charge_options) { { customer: customer.id, amount: params[:amount], description: stripe_options[:description], currency: stripe_options[:currency] } }
 
       before do