From f2530417fc103d4ed61e578b60e672be44c5917b Mon Sep 17 00:00:00 2001
From: David Chin <davidchin.yf@gmail.com>
Date: Tue, 10 Sep 2019 13:33:05 +1000
Subject: [PATCH] fix(common): CHECKOUT-4412 Retry if unable to load asset
 chunk

---
 src/app/checkout/Checkout.tsx        | 25 +++++++++---------
 src/app/common/utility/index.ts      |  5 ++++
 src/app/common/utility/retry.spec.ts | 38 ++++++++++++++++++++++++++++
 src/app/common/utility/retry.ts      | 28 ++++++++++++++++++++
 src/app/order/OrderConfirmation.tsx  |  9 ++++---
 5 files changed, 89 insertions(+), 16 deletions(-)
 create mode 100644 src/app/common/utility/retry.spec.ts
 create mode 100644 src/app/common/utility/retry.ts

diff --git a/src/app/checkout/Checkout.tsx b/src/app/checkout/Checkout.tsx
index b0e90f3fbd..0b25afb73a 100644
--- a/src/app/checkout/Checkout.tsx
+++ b/src/app/checkout/Checkout.tsx
@@ -7,6 +7,7 @@ import { NoopStepTracker, StepTracker } from '../analytics';
 import { StaticBillingAddress } from '../billing';
 import { EmptyCartMessage } from '../cart';
 import { ErrorLogger, ErrorModal } from '../common/error';
+import { retry } from '../common/utility';
 import { CustomerInfo, CustomerSignOutEvent, CustomerViewType } from '../customer';
 import { isEmbedded, EmbeddedCheckoutStylesheet } from '../embeddedCheckout';
 import { withLanguage, TranslatedString, WithLanguageProps } from '../locale';
@@ -24,35 +25,35 @@ import CheckoutStepStatus from './CheckoutStepStatus';
 import CheckoutStepType from './CheckoutStepType';
 import CheckoutSupport from './CheckoutSupport';
 
-const Billing = lazy(() => import(
+const Billing = lazy(() => retry(() => import(
     /* webpackChunkName: "billing" */
     '../billing/Billing'
-));
+)));
 
-const CartSummary = lazy(() => import(
+const CartSummary = lazy(() => retry(() => import(
     /* webpackChunkName: "cart-summary" */
     '../cart/CartSummary'
-));
+)));
 
-const CartSummaryDrawer = lazy(() => import(
+const CartSummaryDrawer = lazy(() => retry(() => import(
     /* webpackChunkName: "cart-summary-drawer" */
     '../cart/CartSummaryDrawer'
-));
+)));
 
-const Customer = lazy(() => import(
+const Customer = lazy(() => retry(() => import(
     /* webpackChunkName: "customer" */
     '../customer/Customer'
-));
+)));
 
-const Payment = lazy(() => import(
+const Payment = lazy(() => retry(() => import(
     /* webpackChunkName: "payment" */
     '../payment/Payment'
-));
+)));
 
-const Shipping = lazy(() => import(
+const Shipping = lazy(() => retry(() => import(
     /* webpackChunkName: "shipping" */
     '../shipping/Shipping'
-));
+)));
 
 export interface CheckoutProps {
     checkoutId: string;
diff --git a/src/app/common/utility/index.ts b/src/app/common/utility/index.ts
index b80e50305a..4e19bd8c8a 100644
--- a/src/app/common/utility/index.ts
+++ b/src/app/common/utility/index.ts
@@ -1 +1,6 @@
+import { RetryOptions } from './retry';
+
+export type RetryOptions = RetryOptions;
+
 export * from './emptyData';
+export { default as retry } from './retry';
diff --git a/src/app/common/utility/retry.spec.ts b/src/app/common/utility/retry.spec.ts
new file mode 100644
index 0000000000..7a84edbfc6
--- /dev/null
+++ b/src/app/common/utility/retry.spec.ts
@@ -0,0 +1,38 @@
+import retry from './retry';
+
+describe('retry()', () => {
+    it('retries async call for specified number of times', async () => {
+        const error = new Error('Request timeout');
+        const call = jest.fn(() => Promise.reject(error));
+
+        try {
+            await retry(() => call(), { count: 3, interval: 1 });
+        } catch (thrown) {
+            expect(call)
+                .toHaveBeenCalledTimes(3);
+            expect(thrown)
+                .toEqual(error);
+        }
+    });
+
+    it('stops retrying async call if it succeeds', async () => {
+        let times = 0;
+
+        const response = 'Foobar';
+        const error = new Error('Request timeout');
+        const call = jest.fn(() => {
+            times++;
+
+            return times === 2 ?
+                Promise.resolve(response) :
+                Promise.reject(error);
+        });
+
+        const output = await retry(() => call(), { interval: 1 });
+
+        expect(call)
+            .toHaveBeenCalledTimes(2);
+        expect(output)
+            .toEqual(response);
+    });
+});
diff --git a/src/app/common/utility/retry.ts b/src/app/common/utility/retry.ts
new file mode 100644
index 0000000000..00555a9023
--- /dev/null
+++ b/src/app/common/utility/retry.ts
@@ -0,0 +1,28 @@
+const DEFAULT_OPTIONS = {
+    count: 5,
+    interval: 1000,
+};
+
+export interface RetryOptions {
+    count?: number;
+    interval?: number;
+}
+
+export default async function retry<T>(
+    fn: () => Promise<T>,
+    options?: RetryOptions
+): Promise<T> {
+    const { count, interval } = { ...DEFAULT_OPTIONS, ...options };
+
+    try {
+        return await fn();
+    } catch (error) {
+        if (count === 1) {
+            throw error;
+        }
+
+        await new Promise(resolve => setTimeout(resolve, interval));
+
+        return retry(fn, { interval, count: count - 1 });
+    }
+}
diff --git a/src/app/order/OrderConfirmation.tsx b/src/app/order/OrderConfirmation.tsx
index ec917b412a..1a5a39854f 100644
--- a/src/app/order/OrderConfirmation.tsx
+++ b/src/app/order/OrderConfirmation.tsx
@@ -6,6 +6,7 @@ import React, { lazy, Component, Fragment, ReactNode, Suspense } from 'react';
 import { StepTracker } from '../analytics';
 import { withCheckout, CheckoutContextProps } from '../checkout';
 import { ErrorLogger, ErrorModal } from '../common/error';
+import { retry } from '../common/utility';
 import { isEmbedded, EmbeddedCheckoutStylesheet } from '../embeddedCheckout';
 import { CreatedCustomer, GuestSignUpForm, SignedUpSuccessAlert, SignUpFormValues } from '../guestSignup';
 import { AccountCreationFailedError, AccountCreationRequirementsError } from '../guestSignup/errors';
@@ -21,15 +22,15 @@ import OrderStatus from './OrderStatus';
 import PrintLink from './PrintLink';
 import ThankYouHeader from './ThankYouHeader';
 
-const OrderSummary = lazy(() => import(
+const OrderSummary = lazy(() => retry(() => import(
     /* webpackChunkName: "order-summary" */
     './OrderSummary'
-));
+)));
 
-const OrderSummaryDrawer = lazy(() => import(
+const OrderSummaryDrawer = lazy(() => retry(() => import(
     /* webpackChunkName: "order-summary-drawer" */
     './OrderSummaryDrawer'
-));
+)));
 
 export interface OrderConfirmationState {
     error?: Error;