Add method enum field to Payment component

Add new method field to Payment component with 10 payment method values
(bank_debit, bank_redirect, bank_transfer, buy_now_pay_later, card, crypto,
digital_wallet, gift_card, real_time_payment, rewards) to specify the
payment method associated with the transaction. Includes comprehensive
test coverage and documentation.

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

Co-Authored-By: Claude <[email protected]>

Author: horgh

CHANGELOG.md

@@ -10,6 +10,9 @@
 * Added the input `/event/party`. This is the party submitting the
   transaction. You may provide this using the `party` attribute on
   `Minfraud::Components::Event`.
+* Added the input `/payment/method`. This is the payment method associated
+  with the transaction. You may provide this using the `method` attribute
+  on `Minfraud::Components::Payment`.
 
 ## v2.8.0 (2025-05-23)
 

lib/minfraud/components/payment.rb

@@ -9,6 +9,28 @@ class Payment < Base
       include ::Minfraud::Enum
       include Minfraud::Validates
 
+      # The payment method associated with the transaction. This must be one of
+      # +:bank_debit+, +:bank_redirect+, +:bank_transfer+, +:buy_now_pay_later+,
+      # +:card+, +:crypto+, +:digital_wallet+, +:gift_card+,
+      # +:real_time_payment+, or +:rewards+.
+      #
+      # @!attribute method
+      #
+      # @return [Symbol, nil]
+      enum_accessor :method,
+                    %i[
+                      bank_debit
+                      bank_redirect
+                      bank_transfer
+                      buy_now_pay_later
+                      card
+                      crypto
+                      digital_wallet
+                      gift_card
+                      real_time_payment
+                      rewards
+                    ]
+
       # The payment processor used for the transaction. The value is one
       # listed as a valid value, as a symbol.
       #
@@ -196,6 +218,7 @@ class Payment < Base
       def initialize(params = {})
         @was_authorized = params[:was_authorized]
         @decline_code   = params[:decline_code]
+        self.method     = params[:method]
         self.processor  = params[:processor]
 
         validate

spec/components/payment_spec.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Minfraud::Components::Payment do
+  describe '#initialize' do
+    context 'with an invalid processor' do
+      it 'raises an exception' do
+        expect do
+          described_class.new({ processor: :invalid_processor })
+        end.to raise_exception(Minfraud::NotEnumValueError)
+      end
+    end
+
+    context 'with an invalid method' do
+      it 'raises an exception' do
+        expect do
+          described_class.new({ method: :invalid_method })
+        end.to raise_exception(Minfraud::NotEnumValueError)
+      end
+    end
+  end
+
+  describe 'validation' do
+    before do
+      Minfraud.configure { |c| c.enable_validation = 1 }
+    end
+
+    it 'does not raise an exception for valid values' do
+      described_class.new(
+        processor:      :stripe,
+        method:         :card,
+        was_authorized: true,
+        decline_code:   'insufficient_funds',
+      )
+    end
+
+    it 'accepts bank_debit as a valid method' do
+      described_class.new(
+        method: :bank_debit,
+      )
+    end
+
+    it 'accepts digital_wallet as a valid method' do
+      described_class.new(
+        method: :digital_wallet,
+      )
+    end
+
+    it 'accepts buy_now_pay_later as a valid method' do
+      described_class.new(
+        method: :buy_now_pay_later,
+      )
+    end
+  end
+end