refactor(helcim): normalize listHelcimCustomerCards return shape

tests/server/utils/helcim.test.js

@@ -1,6 +1,7 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
 
 import {
+  listHelcimCustomerCards,
   listHelcimCustomerTransactions,
   updateHelcimCustomerDefaultPaymentMethod,
   updateHelcimSubscriptionPaymentMethod
@@ -25,6 +26,56 @@ function errResponse(status = 500, body = 'boom') {
   }
 }
 
+describe('listHelcimCustomerCards', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+  afterEach(() => {
+    mockFetch.mockReset()
+  })
+
+  it('passes through a bare array response', async () => {
+    const cards = [
+      { id: 1, cardToken: 'tok-a' },
+      { id: 2, cardToken: 'tok-b' }
+    ]
+    mockFetch.mockResolvedValue(okResponse(cards))
+
+    const result = await listHelcimCustomerCards('2488717')
+
+    expect(result).toEqual(cards)
+  })
+
+  it('unwraps a { cards: [...] } response envelope', async () => {
+    const cards = [{ id: 1, cardToken: 'tok-a' }]
+    mockFetch.mockResolvedValue(okResponse({ cards }))
+
+    const result = await listHelcimCustomerCards('2488717')
+
+    expect(result).toEqual(cards)
+  })
+
+  it('unwraps a { data: [...] } response envelope', async () => {
+    const cards = [{ id: 1, cardToken: 'tok-a' }]
+    mockFetch.mockResolvedValue(okResponse({ data: cards }))
+
+    const result = await listHelcimCustomerCards('2488717')
+
+    expect(result).toEqual(cards)
+  })
+
+  it('returns an empty array for null, undefined, or unrecognized object responses', async () => {
+    mockFetch.mockResolvedValueOnce(okResponse(null))
+    expect(await listHelcimCustomerCards('2488717')).toEqual([])
+
+    mockFetch.mockResolvedValueOnce(okResponse(undefined))
+    expect(await listHelcimCustomerCards('2488717')).toEqual([])
+
+    mockFetch.mockResolvedValueOnce(okResponse({ unexpected: 'shape' }))
+    expect(await listHelcimCustomerCards('2488717')).toEqual([])
+  })
+})
+
 describe('listHelcimCustomerTransactions', () => {
   beforeEach(() => {
     vi.clearAllMocks()