static page support for modules (source-academy#1098)

Add modules repository as a submodule and change the module backend URL according to the .env file.

Author: Hou-Rui

.env.example

@@ -2,4 +2,6 @@ REACT_APP_LUMINUS_CLIENT_ID=your_luminus_client_id_here
 REACT_APP_VERSION=$npm_package_version
 REACT_APP_BACKEND_URL=http://localhost:4001
 REACT_APP_USE_BACKEND=TRUE
-REACT_APP_CHATKIT_INSTANCE_LOCATOR=instance_locator_here_otherwise_empty_string
+REACT_APP_CHATKIT_INSTANCE_LOCATOR=instance_locator_here_otherwise_empty_string
+
+MODULE_BACKEND_URL=http://ec2-54-169-81-133.ap-southeast-1.compute.amazonaws.com

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "public/modules"]
+	path = public/modules
+	url = https://github.com/source-academy/modules.git

package-lock.json

@@ -47,7 +47,7 @@
     "draft-js": "^0.10.5",
     "flexboxgrid": "^6.3.1",
     "flexboxgrid-helpers": "^1.1.3",
-    "js-slang": "^0.4.44",
+    "js-slang": "^0.4.45",
     "jwt-decode": "^2.2.0",
     "lodash": "^4.17.15",
     "lz-string": "^1.4.4",

package.json

@@ -1,11 +1,13 @@
+import { setBackendStaticURL } from 'js-slang/dist/modules/moduleLoader';
+
 import * as React from 'react';
 import { render } from 'react-dom';
 import { Provider } from 'react-redux';
 import { ConnectedRouter } from 'react-router-redux';
 
 import ApplicationContainer from './containers/ApplicationContainer';
 import { store } from './createStore';
-import { LINKS, SOURCE_ACADEMY_VERSION } from './utils/constants';
+import { LINKS, MODULE_BACKEND_URL, SOURCE_ACADEMY_VERSION } from './utils/constants';
 import { history } from './utils/history';
 import registerServiceWorker from './utils/registerServiceWorker';
 
@@ -20,6 +22,10 @@ console.log(
   'font-weight: bold;'
 );
 
+setBackendStaticURL(MODULE_BACKEND_URL);
+// tslint:disable-next-line
+console.log(`Using module backend: ${MODULE_BACKEND_URL}`);
+
 render(
   <Provider store={store}>
     <ConnectedRouter history={history}>

public/modules

@@ -16,6 +16,11 @@ export const INSTANCE_LOCATOR = process.env.REACT_APP_CHATKIT_INSTANCE_LOCATOR;
 export const DEFAULT_SOURCE_CHAPTER = 4;
 export const DEFAULT_SOURCE_VARIANT = 'default';
 
+export const MODULE_BACKEND_URL =
+  process.env.MODULE_BACKEND_URL === undefined || process.env.MODULE_BACKEND_URL === ''
+    ? 'modules'
+    : process.env.MODULE_BACKEND_URL;
+
 export enum LINKS {
   GITHUB_ISSUES = 'https://github.com/source-academy/cadet-frontend/issues',
   GITHUB_ORG = 'https://github.com/source-academy',

src/index.tsx

@@ -21,6 +21,7 @@
   "exclude": [
     "node_modules",
     "public/externalLibs",
+    "public/modules",
     "build",
     "scripts",
     "acceptance-tests",