Add Stripe Cancellation Webhook

Envfile

@@ -130,6 +130,7 @@ variable :SLACK_WEBHOOK_URL, :String, default: "Optional"
 # Stripe for payment system
 variable :STRIPE_PUBLISHABLE_KEY, :String, default: "Optional"
 variable :STRIPE_SECRET_KEY, :String, default: "Optional"
+variable :STRIPE_CANCELLATION_SECRET, :String, default: "Optional"
 
 # For browser webpush notifications (webpush gem) (totally random base64 nums)
 variable :VAPID_PUBLIC_KEY, :String, default: "dGhpcyBpcyBkZXYudG8gdGVzdCBkYXRh"

app/controllers/stripe_cancellations_controller.rb

@@ -0,0 +1,39 @@
+class StripeCancellationsController < ApplicationController
+  skip_before_action :verify_authenticity_token, only: :create
+
+  def create
+    verify_stripe_signature
+    unsubscribe_customer
+  end
+
+  def verify_stripe_signature
+    payload = request.body.read
+    sig_header = request.env["HTTP_STRIPE_SIGNATURE"]
+
+    begin
+      Stripe::Webhook.construct_event(
+        payload, sig_header, Rails.configuration.stripe[:stripe_cancellation_secret]
+      )
+    rescue JSON::ParserError
+      # Invalid payload
+      status 400
+      return
+    rescue Stripe::SignatureVerificationError
+      # Invalid signature
+      status 400
+      return
+    end
+  end
+
+  def unsubscribe_customer
+    event = Stripe::Event.retrieve(params[:id])
+    stripe_id = event.data.object.customer
+    customer = Stripe::Customer.retrieve(stripe_id)
+    monthly_dues = event.data.object.items.data[0].plan.amount
+    user = User.where(stripe_id_code: stripe_id).first
+    MembershipService.new(customer, user, monthly_dues).unsubscribe_customer
+    render body: nil, status: 200
+  rescue Stripe::APIConnectionError, Stripe::StripeError
+    render body: nil, status: 400
+  end
+end

app/services/membership_service.rb

@@ -42,6 +42,8 @@ def create_subscription
   end
 
   def cancel_subscription
+    return true if customer.subscriptions.none?
+
     subscription.delete
   end
 

config/initializers/stripe.rb

@@ -1,6 +1,7 @@
 Rails.configuration.stripe = {
   publishable_key: ApplicationConfig["STRIPE_PUBLISHABLE_KEY"],
-  secret_key: ApplicationConfig["STRIPE_SECRET_KEY"]
+  secret_key: ApplicationConfig["STRIPE_SECRET_KEY"],
+  stripe_cancellation_secret: ApplicationConfig["STRIPE_CANCELLATION_SECRET"]
 }
 
 Stripe.api_key = Rails.configuration.stripe[:secret_key]

config/routes.rb

@@ -112,6 +112,7 @@
   resources :tags, only: [:index]
   resources :stripe_subscriptions, only: %i[create update destroy]
   resources :stripe_active_cards, only: %i[create update destroy]
+  resources :stripe_cancellations, only: [:create]
   resources :live_articles, only: [:index]
   resources :github_repos, only: %i[create update]
   resources :buffered_articles, only: [:index]

spec/requests/stripe_cancellations_spec.rb

@@ -0,0 +1,32 @@
+require "rails_helper"
+
+RSpec.describe "StripeCancellations", type: :request do
+  let(:user) { create(:user) }
+  let(:stripe_helper) { StripeMock.create_test_helper }
+
+  before do
+    StripeMock.start
+    allow_any_instance_of(StripeCancellationsController).to receive(:verify_stripe_signature).and_return(true)
+  end
+
+  after { StripeMock.stop }
+
+  it "mocks a stripe cancellation webhook" do
+    customer = Stripe::Customer.create(
+      email: user.email,
+      source: stripe_helper.generate_card_token,
+    )
+    MembershipService.new(customer, user, 12).subscribe_customer
+    user.reload
+    expect(user.monthly_dues).not_to eq(0)
+
+    event = StripeMock.mock_webhook_event(
+      "customer.subscription.deleted",
+      customer: user.stripe_id_code, total_count: 1,
+    )
+    post "/stripe_cancellations", params: event.as_json
+    user.reload
+    expect(user.monthly_dues).to eq(0)
+    expect(response).to have_http_status(200)
+  end
+end