refactor(billing): rename coerce to to_supported and fix find_plan param name

enterprise/app/services/enterprise/billing/currencies.rb

@@ -29,8 +29,8 @@ module Enterprise::Billing::Currencies
     SUPPORTED.include?(normalize(code))
   end
 
-  # Coerce arbitrary input to a usable supported code, else DEFAULT.
-  def coerce(code)
+  # Map arbitrary input to a supported code, else DEFAULT.
+  def to_supported(code)
     supported?(code) ? normalize(code) : DEFAULT
   end
 
@@ -39,10 +39,10 @@ module Enterprise::Billing::Currencies
   end
 
   def country_for(code)
-    COUNTRY_BY_CURRENCY[coerce(code)]
+    COUNTRY_BY_CURRENCY[to_supported(code)]
   end
 
   def preferred_locale_for(code)
-    PREFERRED_LOCALE_BY_CURRENCY[coerce(code)]
+    PREFERRED_LOCALE_BY_CURRENCY[to_supported(code)]
   end
 end

enterprise/app/services/enterprise/billing/handle_stripe_event_service.rb

@@ -151,7 +151,7 @@ class Enterprise::Billing::HandleStripeEventService
     @account ||= Account.where("custom_attributes->>'stripe_customer_id' = ?", subscription.customer).first
   end
 
-  def find_plan(plan_id)
-    Enterprise::Billing::PlanConfiguration.find_plan_by_product_id(plan_id)
+  def find_plan(product_id)
+    Enterprise::Billing::PlanConfiguration.find_plan_by_product_id(product_id)
   end
 end

enterprise/app/services/enterprise/billing/plan_configuration.rb

@@ -25,7 +25,7 @@ module Enterprise::Billing::PlanConfiguration
   # Price id for `plan` in `currency`, falling back to usd then any configured price.
   def price_id_for(plan, currency)
     by_currency = price_ids_by_currency(plan)
-    code = Enterprise::Billing::Currencies.coerce(currency)
+    code = Enterprise::Billing::Currencies.to_supported(currency)
 
     (by_currency[code].presence ||
      by_currency[Enterprise::Billing::Currencies::DEFAULT].presence ||