feat: allow increment response to accept credits

enterprise/app/models/enterprise/account/plan_usage_and_limits.rb

@@ -15,9 +15,9 @@ module Enterprise::Account::PlanUsageAndLimits
     }
   end
 
-  def increment_response_usage
+  def increment_response_usage(credits: 1)
     current_usage = custom_attributes[CAPTAIN_RESPONSES_USAGE].to_i || 0
-    custom_attributes[CAPTAIN_RESPONSES_USAGE] = current_usage + 1
+    custom_attributes[CAPTAIN_RESPONSES_USAGE] = current_usage + credits
     save
   end
 

spec/enterprise/models/enterprise/account/plan_usage_and_limits_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Enterprise::Account::PlanUsageAndLimits do
+  let(:account) { create(:account) }
+
+  describe '#increment_response_usage' do
+    it 'increments usage by 1 by default' do
+      initial_usage = account.custom_attributes['captain_responses_usage'].to_i
+      account.increment_response_usage
+      account.reload
+      expect(account.custom_attributes['captain_responses_usage']).to eq(initial_usage + 1)
+    end
+
+    it 'increments usage by the specified credits' do
+      initial_usage = account.custom_attributes['captain_responses_usage'].to_i
+      account.increment_response_usage(credits: 3)
+      account.reload
+      expect(account.custom_attributes['captain_responses_usage']).to eq(initial_usage + 3)
+    end
+
+    it 'handles zero initial usage' do
+      account.custom_attributes['captain_responses_usage'] = nil
+      account.save!
+      account.increment_response_usage(credits: 2)
+      account.reload
+      expect(account.custom_attributes['captain_responses_usage']).to eq(2)
+    end
+  end
+end