From 6cf2ab47ea728cf1f0e2f7e683e2a202215b87f9 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 27 May 2021 00:27:12 +0200
Subject: [PATCH] app-api: sync with core at master@e9e70677

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 packages/app-api/src/app/createApp.test.tsx | 25 +++++++++++++++++++-
 packages/app-api/src/app/createApp.tsx      | 26 +++++++++++++++++----
 2 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/packages/app-api/src/app/createApp.test.tsx b/packages/app-api/src/app/createApp.test.tsx
index 31f584b68c..a800c11ea6 100644
--- a/packages/app-api/src/app/createApp.test.tsx
+++ b/packages/app-api/src/app/createApp.test.tsx
@@ -14,7 +14,10 @@
  * limitations under the License.
  */
 
-import { defaultConfigLoader } from './createApp';
+import { render } from '@testing-library/react';
+import React from 'react';
+import { MemoryRouter } from 'react-router-dom';
+import { defaultConfigLoader, OptionallyWrapInRouter } from './createApp';
 
 (process as any).env = { NODE_ENV: 'test' };
 const anyEnv = process.env as any;
@@ -92,3 +95,23 @@ describe('defaultConfigLoader', () => {
     ]);
   });
 });
+
+describe('OptionallyWrapInRouter', () => {
+  it('should wrap with router if not yet inside a router', async () => {
+    const { getByText } = render(
+      <OptionallyWrapInRouter>Test</OptionallyWrapInRouter>,
+    );
+
+    expect(getByText('Test')).toBeInTheDocument();
+  });
+
+  it('should not wrap with router if already inside a router', async () => {
+    const { getByText } = render(
+      <MemoryRouter>
+        <OptionallyWrapInRouter>Test</OptionallyWrapInRouter>
+      </MemoryRouter>,
+    );
+
+    expect(getByText('Test')).toBeInTheDocument();
+  });
+});
diff --git a/packages/app-api/src/app/createApp.tsx b/packages/app-api/src/app/createApp.tsx
index 445e7495ef..a0ef11199a 100644
--- a/packages/app-api/src/app/createApp.tsx
+++ b/packages/app-api/src/app/createApp.tsx
@@ -14,10 +14,14 @@
  * limitations under the License.
  */
 
-import React from 'react';
+import React, { PropsWithChildren } from 'react';
 import { AppOptions, BootErrorPageProps, AppConfigLoader } from './types';
 import { defaultAppIcons } from './icons';
-import { BrowserRouter, MemoryRouter } from 'react-router-dom';
+import {
+  BrowserRouter,
+  MemoryRouter,
+  useInRouterContext,
+} from 'react-router-dom';
 import LightIcon from '@material-ui/icons/WbSunny';
 import DarkIcon from '@material-ui/icons/Brightness2';
 import { ErrorPage, Progress } from '@backstage/components';
@@ -52,7 +56,10 @@ export const defaultConfigLoader: AppConfigLoader = async (
   const configs = (appConfig.slice() as unknown) as AppConfig[];
 
   // Avoiding this string also being replaced at runtime
-  if (runtimeConfigJson !== '__app_injected_runtime_config__'.toUpperCase()) {
+  if (
+    runtimeConfigJson !==
+    '__app_injected_runtime_config__'.toLocaleUpperCase('en-US')
+  ) {
     try {
       const data = JSON.parse(runtimeConfigJson) as JsonObject;
       if (Array.isArray(data)) {
@@ -80,6 +87,13 @@ export const defaultConfigLoader: AppConfigLoader = async (
 // The actual implementation of the app class still lives in core-api,
 // as it needs to be used by dev- and test-utils.
 
+export function OptionallyWrapInRouter({ children }: PropsWithChildren<{}>) {
+  if (useInRouterContext()) {
+    return <>{children}</>;
+  }
+  return <MemoryRouter>{children}</MemoryRouter>;
+}
+
 /**
  * Creates a new Backstage App.
  */
@@ -91,12 +105,14 @@ export function createApp(options?: AppOptions) {
     let message = '';
     if (step === 'load-config') {
       message = `The configuration failed to load, someone should have a look at this error: ${error.message}`;
+    } else if (step === 'load-chunk') {
+      message = `Lazy loaded chunk failed to load, try to reload the page: ${error.message}`;
     }
     // TODO: figure out a nicer way to handle routing on the error page, when it can be done.
     return (
-      <MemoryRouter>
+      <OptionallyWrapInRouter>
         <ErrorPage status="501" statusMessage={message} />
-      </MemoryRouter>
+      </OptionallyWrapInRouter>
     );
   };