Fix bug where transaction id is not recognised

packages/gafl-webapp-service/src/handlers/__tests__/agreed-handler-recurring-payments.spec.js

@@ -36,7 +36,7 @@ describe('The agreed handler', () => {
     cache: () => ({
       helpers: {
         transaction: {
-          get: async () => ({ id: 'id-111', cost: 0 }),
+          get: async () => ({ cost: 0 }),
           set: async () => {}
         },
         status: {
@@ -90,6 +90,41 @@ describe('The agreed handler', () => {
       expect(transactionPayload.id).toBe(v4guid)
     })
 
+    it("doesn't overwrite transaction id if one is already set", async () => {
+      const setTransaction = jest.fn()
+      const transactionId = 'abc-123-def-456'
+      uuidv4.mockReturnValue('def-789-ghi-012')
+      salesApi.finaliseTransaction.mockReturnValueOnce({
+        permissions: []
+      })
+      const mockRequest = {
+        cache: () => ({
+          helpers: {
+            status: {
+              get: async () => ({
+                [COMPLETION_STATUS.agreed]: true,
+                [COMPLETION_STATUS.posted]: true,
+                [COMPLETION_STATUS.finalised]: false,
+                [RECURRING_PAYMENT]: false
+              }),
+              set: () => {}
+            },
+            transaction: {
+              get: async () => ({ cost: 0, id: transactionId }),
+              set: setTransaction
+            }
+          }
+        })
+      }
+
+      await agreedHandler(mockRequest, getRequestToolkit())
+
+      expect(salesApi.finaliseTransaction).toHaveBeenCalledWith(
+        transactionId,
+        undefined // prepareApiFinalisationPayload has no mocked return value
+      )
+    })
+
     it('sends a recurring payment creation request to Gov.UK Pay', async () => {
       const preparedPayment = Symbol('preparedPayment')
       prepareRecurringPayment.mockResolvedValueOnce(preparedPayment)

packages/gafl-webapp-service/src/handlers/agreed-handler.js

@@ -241,7 +241,9 @@ const finaliseTransaction = async (request, transaction, status) => {
 export default async (request, h) => {
   const status = await request.cache().helpers.status.get()
   const transaction = await request.cache().helpers.transaction.get()
-  transaction.id = uuidv4()
+  if (!transaction.id) {
+    transaction.id = uuidv4()
+  }
 
   // If the agreed flag is not set to true then throw an exception
   if (!status[COMPLETION_STATUS.agreed]) {
@@ -279,6 +281,7 @@ export default async (request, h) => {
 
   // If the transaction has already been finalised then redirect to the order completed page
   if (!status[COMPLETION_STATUS.finalised]) {
+    console.log('finalising transaction', request, transaction, status)
     await finaliseTransaction(request, transaction, status)
   } else {
     debug('Transaction %s already finalised, redirect to order complete: %s', transaction.id)