feat: wire payment return url payloads

frontend/src/components/payment/__tests__/paymentFlow.spec.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from 'vitest'
 import type { CreateOrderResult, MethodLimit } from '@/types/payment'
 import {
+  buildCreateOrderPayload,
   decidePaymentLaunch,
   getVisibleMethods,
   readPaymentRecoverySnapshot,
@@ -106,6 +107,42 @@ describe('decidePaymentLaunch', () => {
   })
 })
 
+describe('buildCreateOrderPayload', () => {
+  it('normalizes visible method aliases and attaches a canonical result URL', () => {
+    expect(buildCreateOrderPayload({
+      amount: 88,
+      paymentType: 'alipay_direct',
+      orderType: 'balance',
+      origin: 'https://app.example.com/',
+      isWechatBrowser: false,
+    })).toEqual({
+      amount: 88,
+      payment_type: 'alipay',
+      order_type: 'balance',
+      return_url: 'https://app.example.com/payment/result',
+      payment_source: 'hosted_redirect',
+    })
+  })
+
+  it('uses WeChat in-app resume source for visible WeChat payments in the WeChat browser', () => {
+    expect(buildCreateOrderPayload({
+      amount: 128,
+      paymentType: 'wxpay',
+      orderType: 'subscription',
+      planId: 7,
+      origin: 'https://app.example.com',
+      isWechatBrowser: true,
+    })).toEqual({
+      amount: 128,
+      payment_type: 'wxpay',
+      order_type: 'subscription',
+      plan_id: 7,
+      return_url: 'https://app.example.com/payment/result',
+      payment_source: 'wechat_in_app_resume',
+    })
+  })
+})
+
 describe('readPaymentRecoverySnapshot', () => {
   it('restores an unexpired snapshot when the resume token matches', () => {
     const snapshot: PaymentRecoverySnapshot = {

frontend/src/components/payment/paymentFlow.ts

@@ -1,4 +1,4 @@
-import type { CreateOrderResult, MethodLimit, OrderType } from '@/types/payment'
+import type { CreateOrderRequest, CreateOrderResult, MethodLimit, OrderType } from '@/types/payment'
 
 export const PAYMENT_RECOVERY_STORAGE_KEY = 'payment.recovery.current'
 
@@ -49,6 +49,15 @@ export interface PaymentLaunchDecision {
   stripeMethod?: StripeVisibleMethod
 }
 
+export interface BuildCreateOrderPayloadInput {
+  amount: number
+  paymentType: string
+  orderType: OrderType
+  planId?: number
+  origin?: string
+  isWechatBrowser: boolean
+}
+
 type CreateOrderFlowResult = CreateOrderResult & {
   resume_token?: string
 }
@@ -77,6 +86,28 @@ export function getVisibleMethods(methods: Record<string, MethodLimit>): Record<
   return visible
 }
 
+export function buildCreateOrderPayload(input: BuildCreateOrderPayloadInput): CreateOrderRequest {
+  const visibleMethod = normalizeVisibleMethod(input.paymentType) || input.paymentType.trim()
+  const normalizedOrigin = (input.origin || '').trim().replace(/\/+$/, '')
+  const payload: CreateOrderRequest = {
+    amount: input.amount,
+    payment_type: visibleMethod,
+    order_type: input.orderType,
+    payment_source: visibleMethod === 'wxpay' && input.isWechatBrowser
+      ? 'wechat_in_app_resume'
+      : 'hosted_redirect',
+  }
+
+  if (input.planId) {
+    payload.plan_id = input.planId
+  }
+  if (normalizedOrigin) {
+    payload.return_url = `${normalizedOrigin}/payment/result`
+  }
+
+  return payload
+}
+
 export function decidePaymentLaunch(
   result: CreateOrderFlowResult,
   context: PaymentLaunchContext,