Add method to locate plans by the stripe price id

saas/app/controllers/stripe/webhooks_controller.rb

@@ -80,6 +80,6 @@ class Stripe::WebhooksController < ApplicationController
 
     def plan_key_for(stripe_subscription)
       price_id = stripe_subscription.items.data.first&.price&.id
-      Plan.all.find { |plan| plan.stripe_price_id == price_id }&.key
+      Plan.find_by_price_id(price_id)&.key
     end
 end

saas/app/models/plan.rb

@@ -29,6 +29,10 @@ class Plan
       @all_by_key[key]
     end
 
+    def find_by_price_id(price_id)
+      all.find { |plan| plan.stripe_price_id == price_id }
+    end
+
     alias [] find
   end
 

saas/test/models/plan_test.rb

@@ -8,4 +8,11 @@ class PlanTest < ActiveSupport::TestCase
   test "monthly plan is not free" do
     assert_not Plan[:monthly_v1].free?
   end
+
+  test "find plan by its price id" do
+    Plan.paid.stubs(:stripe_price_id).returns("price_monthly_v1")
+
+    assert_equal Plan.paid, Plan.find_by_price_id("price_monthly_v1")
+    assert_nil Plan.find_by_price_id("unknown_price_id")
+  end
 end