fix(cbe): update response code from 3 to 2 for business failures in CBE integration

integration/src/cbe-bill.it.ts

@@ -122,15 +122,18 @@ describe("CBE Unified Bill (payment service as biller)", () => {
       End_To_End_Txn_Id: txnId("q404"),
       Bill_Id: "000000000000",
     });
-    // Business failures are HTTP 200 + Response_Code "3" — CBE treats a non-200
+    // Business failures are HTTP 200 + Response_Code "2" — CBE treats a non-200
     // as a channel fault and retries.
     expect(res.status).toBe(200);
-    expect(res.body.Response_Code).toBe("3");
+    expect(res.body.Response_Code).toBe("2");
   });
 
+  let settleBody: Record<string, string>;
+  let settledTxnRef: string;
+
   it("settles the freight invoice when CBE reports the debit", async () => {
     const invoice = await currentInvoice(invoiceId);
-    const res = await cbe(token, "/cbe/payment", {
+    settleBody = {
       Destination_Api_Name: API_NAME,
       End_To_End_Txn_Id: txnId("p1"),
       Cbe_Txn_Ref: `CBE${Date.now()}`,
@@ -140,9 +143,11 @@ describe("CBE Unified Bill (payment service as biller)", () => {
       Currency: "ETB",
       Full_Name: "IT Payer",
       Phone_No: "+251911000001",
-    });
+    };
+    const res = await cbe(token, "/cbe/payment", settleBody);
     expect(res.status).toBe(200);
     expect(res.body.Response_Code).toBe("0");
+    settledTxnRef = res.body.Destination_Txn_Ref;
 
     const paid = await poll<{ status: string }>(
       "invoice PAID via CBE bill",
@@ -154,6 +159,24 @@ describe("CBE Unified Bill (payment service as biller)", () => {
     expect(paid.status).toBe("PAID");
   });
 
+  it("replays the stored success when CBE retries the same attempt verbatim", async () => {
+    const res = await cbe(token, "/cbe/payment", settleBody);
+    expect(res.status).toBe(200);
+    expect(res.body.Response_Code).toBe("0");
+    // The stored body, not a re-settlement — same order id as the first answer.
+    expect(res.body.Destination_Txn_Ref).toBe(settledTxnRef);
+  });
+
+  it("rejects a settled End_To_End_Txn_Id reused with a different amount", async () => {
+    const res = await cbe(token, "/cbe/payment", {
+      ...settleBody,
+      Amount: "1.00",
+    });
+    expect(res.status).toBe(200);
+    expect(res.body.Response_Code).toBe("2");
+    expect(res.body.Response_Description).toContain("already used by a different payment");
+  });
+
   it("rejects a second debit on the same bill", async () => {
     const res = await cbe(token, "/cbe/payment", {
       Destination_Api_Name: API_NAME,
@@ -165,7 +188,7 @@ describe("CBE Unified Bill (payment service as biller)", () => {
       Currency: "ETB",
     });
     expect(res.status).toBe(200);
-    expect(res.body.Response_Code).toBe("3");
+    expect(res.body.Response_Code).toBe("2");
   });
 
   it("reports an already-paid bill on a later query", async () => {
@@ -175,6 +198,6 @@ describe("CBE Unified Bill (payment service as biller)", () => {
       Bill_Id: billId,
     });
     expect(res.status).toBe(200);
-    expect(res.body.Response_Code).toBe("3");
+    expect(res.body.Response_Code).toBe("2");
   });
 });