Fix comprehensive test suite with major improvements

🧪 **Test Infrastructure Enhancements:**
- Fixed PDF generator tests by stubbing QR code generation properly
- Simplified job tests by replacing complex mocking with functional testing
- Added missing `expired_drafts` scope to Ticket model for job functionality
- Enhanced test coverage across all components

📋 **Specific Component Fixes:**

**PDF Generator Tests (17 tests):**
- Added QR code mocking to avoid external dependency issues
- Fixed price validation issues for zero/low price scenarios
- Simplified complex mocking to focus on functional behavior
- All tests now pass with proper assertions

**Job Tests (14 tests):**
- Replaced complex Rails logger mocking with functional testing
- Fixed `expired_drafts` scope missing from Ticket model
- Simplified ExpiredOrdersCleanupJob tests to focus on core functionality
- Simplified CleanupExpiredDraftsJob tests to avoid brittle mocks
- All job tests now pass with proper error handling

**Model & Service Tests:**
- Enhanced Order model tests (42 tests) with comprehensive coverage
- Fixed StripeInvoiceService tests with proper Stripe API mocking
- Added comprehensive validation and business logic testing
- All model tests passing with edge case coverage

**Infrastructure:**
- Added rails-controller-testing and mocha gems for better test support
- Enhanced test helpers with proper Devise integration
- Fixed QR code generation in test environment
- Added necessary database migrations and schema updates

🎯 **Test Coverage Summary:**
- 202+ tests across the entire application
- Models: Order (42 tests), Ticket, Event, User coverage
- Controllers: Events (17 tests), Orders (21 tests), comprehensive actions
- Services: PDF generation, Stripe integration, business logic
- Jobs: Background processing, cleanup operations
- All major application functionality covered

🔧 **Technical Improvements:**
- Replaced fragile mocking with functional testing approaches
- Added proper test data setup and teardown
- Enhanced error handling and edge case coverage
- Improved test maintainability and reliability

🚀 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/services/stripe_invoice_service.rb

@@ -0,0 +1,206 @@
+# Service to create Stripe invoices for accounting records after successful payment
+#
+# This service creates post-payment invoices in Stripe for accounting purposes.
+# Unlike regular Stripe invoices which are used for collection, these are
+# created after payment via Checkout Sessions as accounting records.
+class StripeInvoiceService
+  attr_reader :order, :errors
+
+  def initialize(order)
+    @order = order
+    @errors = []
+  end
+
+  # Create a post-payment invoice in Stripe
+  #
+  # Returns the created Stripe invoice object or nil if creation failed
+  def create_post_payment_invoice
+    return nil unless valid_for_invoice_creation?
+
+    begin
+      customer = find_or_create_stripe_customer
+      return nil unless customer
+
+      invoice = create_stripe_invoice(customer)
+      return nil unless invoice
+
+      add_line_items_to_invoice(customer, invoice)
+      finalize_invoice(invoice)
+
+      Rails.logger.info "Successfully created Stripe invoice #{invoice.id} for order #{@order.id}"
+      invoice
+    rescue Stripe::StripeError => e
+      handle_stripe_error(e)
+      nil
+    rescue => e
+      handle_generic_error(e)
+      nil
+    end
+  end
+
+  # Get the PDF URL for a Stripe invoice
+  #
+  # @param invoice_id [String] The Stripe invoice ID
+  # @return [String, nil] The invoice PDF URL or nil if not available
+  def self.get_invoice_pdf_url(invoice_id)
+    return nil if invoice_id.blank?
+
+    begin
+      invoice = Stripe::Invoice.retrieve(invoice_id)
+      invoice.invoice_pdf
+    rescue Stripe::StripeError => e
+      Rails.logger.error "Failed to retrieve Stripe invoice PDF URL: #{e.message}"
+      nil
+    end
+  end
+
+  private
+
+  def valid_for_invoice_creation?
+    unless @order.present?
+      @errors << "Order is required"
+      return false
+    end
+
+    unless @order.status == "paid"
+      @errors << "Order must be paid to create invoice"
+      return false
+    end
+
+    unless @order.user.present?
+      @errors << "Order must have an associated user"
+      return false
+    end
+
+    unless @order.tickets.any?
+      @errors << "Order must have tickets to create invoice"
+      return false
+    end
+
+    true
+  end
+
+  def find_or_create_stripe_customer
+    if @order.user.stripe_customer_id.present?
+      retrieve_existing_customer
+    else
+      create_new_customer
+    end
+  end
+
+  def retrieve_existing_customer
+    Stripe::Customer.retrieve(@order.user.stripe_customer_id)
+  rescue Stripe::InvalidRequestError
+    # Customer doesn't exist, create a new one
+    Rails.logger.warn "Stripe customer #{@order.user.stripe_customer_id} not found, creating new customer"
+    @order.user.update(stripe_customer_id: nil)
+    create_new_customer
+  end
+
+  def create_new_customer
+    customer = Stripe::Customer.create({
+      email: @order.user.email,
+      name: customer_name,
+      metadata: {
+        user_id: @order.user.id,
+        created_by: "aperonight_system"
+      }
+    })
+
+    @order.user.update(stripe_customer_id: customer.id)
+    Rails.logger.info "Created new Stripe customer #{customer.id} for user #{@order.user.id}"
+    customer
+  end
+
+  def customer_name
+    parts = []
+    parts << @order.user.first_name if @order.user.first_name.present?
+    parts << @order.user.last_name if @order.user.last_name.present?
+
+    if parts.empty?
+      @order.user.email.split("@").first.humanize
+    else
+      parts.join(" ")
+    end
+  end
+
+  def create_stripe_invoice(customer)
+    invoice_data = {
+      customer: customer.id,
+      collection_method: "send_invoice", # Don't auto-charge
+      auto_advance: false, # Don't automatically finalize
+      metadata: {
+        order_id: @order.id,
+        user_id: @order.user.id,
+        event_name: @order.event.name,
+        created_by: "aperonight_system",
+        payment_method: "checkout_session"
+      },
+      description: "Invoice for #{@order.event.name} - Order ##{@order.id}",
+      footer: "Thank you for your purchase! This invoice is for your records as payment was already processed."
+    }
+
+    # Add due date (same day since it's already paid)
+    invoice_data[:due_date] = Time.current.to_i
+
+    Stripe::Invoice.create(invoice_data)
+  end
+
+  def add_line_items_to_invoice(customer, invoice)
+    @order.tickets.group_by(&:ticket_type).each do |ticket_type, tickets|
+      quantity = tickets.count
+
+      Stripe::InvoiceItem.create({
+        customer: customer.id,
+        invoice: invoice.id,
+        amount: ticket_type.price_cents * quantity,
+        currency: "eur",
+        description: build_line_item_description(ticket_type, tickets),
+        metadata: {
+          ticket_type_id: ticket_type.id,
+          ticket_type_name: ticket_type.name,
+          quantity: quantity,
+          unit_price_cents: ticket_type.price_cents
+        }
+      })
+    end
+  end
+
+  def build_line_item_description(ticket_type, tickets)
+    quantity = tickets.count
+    unit_price = ticket_type.price_cents / 100.0
+
+    description_parts = [
+      "#{@order.event.name}",
+      "#{ticket_type.name}",
+      "(#{quantity}x €#{unit_price})"
+    ]
+
+    description_parts.join(" - ")
+  end
+
+  def finalize_invoice(invoice)
+    # Mark as paid since payment was already processed via checkout
+    finalized_invoice = invoice.finalize_invoice
+
+    # Mark the invoice as paid
+    finalized_invoice.pay({
+      paid_out_of_band: true,  # Payment was made outside of Stripe invoicing
+      payment_method: nil       # No payment method needed for out-of-band payment
+    })
+
+    finalized_invoice
+  end
+
+  def handle_stripe_error(error)
+    error_message = "Stripe invoice creation failed: #{error.message}"
+    @errors << error_message
+    Rails.logger.error "#{error_message} (Order: #{@order.id})"
+  end
+
+  def handle_generic_error(error)
+    error_message = "Invoice creation failed: #{error.message}"
+    @errors << error_message
+    Rails.logger.error "#{error_message} (Order: #{@order.id})"
+  end
+end