handle transient pay errors (fixes #6607)

Also add a test case for the behavior.

3 files changed, 230 insertions, 8 deletions

diff --git a/packages/taler-integrationtests/src/test-payment-transient.ts b/packages/taler-integrationtests/src/test-payment-transient.ts
new file mode 100644
index 000000000..aa0bda2c5
--- /dev/null
+++ b/packages/taler-integrationtests/src/test-payment-transient.ts
@@ -0,0 +1,169 @@
+/*
+ This file is part of GNU Taler
+ (C) 2020 Taler Systems S.A.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+/**
+ * Imports.
+ */
+import { runTest, GlobalTestState, MerchantPrivateApi } from "./harness";
+import {
+  withdrawViaBank,
+  createFaultInjectedMerchantTestkudosEnvironment,
+} from "./helpers";
+import {
+  PreparePayResultType,
+  codecForMerchantOrderStatusUnpaid,
+  ConfirmPayResultType,
+  URL,
+  codecForExchangeKeysJson,
+  TalerErrorDetails,
+  TalerErrorCode,
+} from "taler-wallet-core";
+import axios from "axios";
+import { FaultInjectionRequestContext, FaultInjectionResponseContext } from "./faultInjection";
+
+/**
+ * Run test for a payment where the merchant has a transient
+ * failure in /pay
+ */
+runTest(async (t: GlobalTestState) => {
+  // Set up test environment
+
+  const {
+    wallet,
+    bank,
+    exchange,
+    faultyMerchant,
+  } = await createFaultInjectedMerchantTestkudosEnvironment(t);
+
+  // Withdraw digital cash into the wallet.
+
+  await withdrawViaBank(t, { wallet, bank, exchange, amount: "TESTKUDOS:20" });
+
+  const merchant = faultyMerchant;
+
+  let orderResp = await MerchantPrivateApi.createOrder(merchant, "default", {
+    order: {
+      summary: "Buy me!",
+      amount: "TESTKUDOS:5",
+      fulfillment_url: "https://example.com/article42",
+    },
+  });
+
+  let orderStatus = await MerchantPrivateApi.queryPrivateOrderStatus(merchant, {
+    orderId: orderResp.order_id,
+    sessionId: "mysession-one",
+  });
+
+  t.assertTrue(orderStatus.order_status === "unpaid");
+
+  t.assertTrue(orderStatus.already_paid_order_id === undefined);
+  let publicOrderStatusUrl = orderStatus.order_status_url;
+
+  let publicOrderStatusResp = await axios.get(publicOrderStatusUrl, {
+    validateStatus: () => true,
+  });
+
+  if (publicOrderStatusResp.status != 402) {
+    throw Error(
+      `expected status 402 (before claiming), but got ${publicOrderStatusResp.status}`,
+    );
+  }
+
+  let pubUnpaidStatus = codecForMerchantOrderStatusUnpaid().decode(
+    publicOrderStatusResp.data,
+  );
+
+  console.log(pubUnpaidStatus);
+
+  let preparePayResp = await wallet.preparePay({
+    talerPayUri: pubUnpaidStatus.taler_pay_uri,
+  });
+
+  t.assertTrue(preparePayResp.status === PreparePayResultType.PaymentPossible);
+
+  const proposalId = preparePayResp.proposalId;
+
+  publicOrderStatusResp = await axios.get(publicOrderStatusUrl, {
+    validateStatus: () => true,
+  });
+
+  if (publicOrderStatusResp.status != 402) {
+    throw Error(
+      `expected status 402 (after claiming), but got ${publicOrderStatusResp.status}`,
+    );
+  }
+
+  pubUnpaidStatus = codecForMerchantOrderStatusUnpaid().decode(
+    publicOrderStatusResp.data,
+  );
+
+  let faultInjected = false;
+
+  faultyMerchant.faultProxy.addFault({
+    modifyResponse(ctx: FaultInjectionResponseContext) {
+      console.log("in modifyResponse");
+      const url = new URL(ctx.request.requestUrl);
+      console.log("pathname is", url.pathname);
+      if (!url.pathname.endsWith("/pay")) {
+        return;
+      }
+      if (faultInjected) {
+        console.log("not injecting pay fault");
+        return;
+      }
+      faultInjected = true;
+      console.log("injecting pay fault");
+      const err: TalerErrorDetails = {
+        code: TalerErrorCode.PAY_DB_FETCH_TRANSACTION_ERROR,
+        details: {},
+        hint: "huh",
+        message: "something went wrong",
+      };
+      ctx.responseBody = Buffer.from(JSON.stringify(err));
+      ctx.statusCode = 500;
+    }
+  });
+
+  const confirmPayResp = await wallet.confirmPay({
+    proposalId,
+  });
+
+  console.log(confirmPayResp);
+
+  t.assertTrue(confirmPayResp.type === ConfirmPayResultType.Pending);
+  t.assertTrue(faultInjected);
+
+  const confirmPayRespTwo = await wallet.confirmPay({
+    proposalId,
+  });
+
+  t.assertTrue(confirmPayRespTwo.type === ConfirmPayResultType.Done);
+
+  // Now ask the merchant if paid
+
+  publicOrderStatusResp = await axios.get(publicOrderStatusUrl, {
+    validateStatus: () => true,
+  });
+
+  console.log(publicOrderStatusResp.data);
+
+  if (publicOrderStatusResp.status != 202) {
+    console.log(publicOrderStatusResp.data);
+    throw Error(
+      `expected status 202 (after paying), but got ${publicOrderStatusResp.status}`,
+    );
+  }
+});
diff --git a/packages/taler-wallet-core/src/operations/pay.ts b/packages/taler-wallet-core/src/operations/pay.ts
index 6079ea08f..442aeca71 100644
--- a/packages/taler-wallet-core/src/operations/pay.ts
+++ b/packages/taler-wallet-core/src/operations/pay.ts
@@ -435,7 +435,7 @@ async function recordConfirmPay(
   } else {
     sessionId = proposal.downloadSessionId;
   }
-  logger.trace(`recording payment with session ID ${sessionId}`);
+  logger.trace(`recording payment on ${proposal.orderId} with session ID ${sessionId}`);
   const payCostInfo = await getTotalPaymentCost(ws, coinSelection);
   const t: PurchaseRecord = {
     abortStatus: AbortStatus.None,
@@ -530,10 +530,6 @@ async function incrementProposalRetry(
   }
 }
 
-/**
- * FIXME: currently pay operations aren't ever automatically retried.
- * But we still keep a payRetryInfo around in the database.
- */
 async function incrementPurchasePayRetry(
   ws: InternalWalletState,
   proposalId: string,
@@ -947,7 +943,7 @@ async function submitPay(
       session_id: purchase.lastSessionId,
     };
 
-    logger.trace("making pay request", JSON.stringify(reqBody, undefined, 2));
+    logger.trace("making pay request ... ", JSON.stringify(reqBody, undefined, 2));
 
     const resp = await ws.runSequentialized([EXCHANGE_COINS_LOCK], () =>
       ws.http.postJson(payUrl, reqBody, {
@@ -955,6 +951,27 @@ async function submitPay(
       }),
     );
 
+    logger.trace(`got resp ${JSON.stringify(resp)}`);
+
+    // Hide transient errors.
+    if (
+      purchase.payRetryInfo.retryCounter <= 5 &&
+      resp.status >= 500 &&
+      resp.status <= 599
+    ) {
+      logger.trace("treating /pay error as transient");
+      const err = makeErrorDetails(
+        TalerErrorCode.WALLET_UNEXPECTED_REQUEST_ERROR,
+        "/pay failed",
+        getHttpResponseErrorDetails(resp),
+      );
+      incrementPurchasePayRetry(ws, proposalId, undefined);
+      return {
+        type: ConfirmPayResultType.Pending,
+        lastError: err,
+      };
+    }
+    
     const merchantResp = await readSuccessResponseJsonOrThrow(
       resp,
       codecForMerchantPayResponse(),
@@ -989,6 +1006,23 @@ async function submitPay(
     const resp = await ws.runSequentialized([EXCHANGE_COINS_LOCK], () =>
       ws.http.postJson(payAgainUrl, reqBody),
     );
+    // Hide transient errors.
+    if (
+      purchase.payRetryInfo.retryCounter <= 5 &&
+      resp.status >= 500 &&
+      resp.status <= 599
+    ) {
+      const err = makeErrorDetails(
+        TalerErrorCode.WALLET_UNEXPECTED_REQUEST_ERROR,
+        "/paid failed",
+        getHttpResponseErrorDetails(resp),
+      );
+      incrementPurchasePayRetry(ws, proposalId, undefined);
+      return {
+        type: ConfirmPayResultType.Pending,
+        lastError: err,
+      };
+    }
     if (resp.status !== 204) {
       throw OperationFailedError.fromCode(
         TalerErrorCode.WALLET_UNEXPECTED_REQUEST_ERROR,
@@ -999,6 +1033,11 @@ async function submitPay(
     await storePayReplaySuccess(ws, proposalId, sessionId);
   }
 
+  ws.notify({
+    type: NotificationType.PayOperationSuccess,
+    proposalId: purchase.proposalId,
+  });
+
   return {
     type: ConfirmPayResultType.Done,
     contractTerms: JSON.parse(purchase.contractTermsRaw),
@@ -1171,7 +1210,7 @@ export async function confirmPay(
 
   let purchase = await ws.db.get(
     Stores.purchases,
-    d.contractData.contractTermsHash,
+    proposalId,
   );
 
   if (purchase) {
diff --git a/packages/taler-wallet-core/src/types/notifications.ts b/packages/taler-wallet-core/src/types/notifications.ts
index d86c5ae59..7faf730ef 100644
--- a/packages/taler-wallet-core/src/types/notifications.ts
+++ b/packages/taler-wallet-core/src/types/notifications.ts
@@ -53,6 +53,7 @@ export enum NotificationType {
   ProposalOperationError = "proposal-error",
   TipOperationError = "tip-error",
   PayOperationError = "pay-error",
+  PayOperationSuccess = "pay-operation-success",
   WithdrawOperationError = "withdraw-error",
   ReserveNotYetFound = "reserve-not-yet-found",
   ReserveOperationError = "reserve-error",
@@ -220,6 +221,18 @@ export interface ReserveRegisteredWithBankNotification {
   type: NotificationType.ReserveRegisteredWithBank;
 }
 
+/**
+ * Notification sent when a pay (or pay replay) operation succeeded.
+ * 
+ * We send this notification because the confirmPay request can return
+ * a "confirmed" response that indicates that the payment has been confirmed
+ * by the user, but we're still waiting for the payment to succeed or fail.
+ */
+export interface PayOperationSuccessNotification {
+  type: NotificationType.PayOperationSuccess;
+  proposalId: string;
+}
+
 export type WalletNotification =
   | WithdrawOperationErrorNotification
   | ReserveOperationErrorNotification
@@ -254,4 +267,5 @@ export type WalletNotification =
   | PendingOperationProcessedNotification
   | ProposalRefusedNotification
   | ReserveRegisteredWithBankNotification
-  | ReserveNotYetFoundNotification;
+  | ReserveNotYetFoundNotification
+  | PayOperationSuccessNotification;