PREAPPS-5789 : adding @babel/plugin-proposal-optional-chaining · Babe…

…l to the plugins

package.json

@@ -45,22 +45,23 @@
   "devDependencies": {
     "@apollo/client": "^3.2.5",
     "@babel/cli": "^7.12.1",
+    "@babel/plugin-proposal-optional-chaining": "^7.12.7",
     "audit-ci": "^3.1.1",
     "babel-eslint": "^10.1.0",
     "eslint": "^7.12.1",
     "eslint-config-synacor": "^3.0.5",
-    "mkdirp": "^1.0.4",
     "graphql": "^15.4.0",
+    "mkdirp": "^1.0.4",
     "mockery": "^2.1.0",
+    "moment": "^2.29.1",
     "preact": "^10.5.5",
     "preact-context-provider": "^2.0.0-preactx.2",
     "preact-i18n": "^2.3.0-preactx",
     "preact-render-to-string": "^5.1.11",
     "preact-router": "github:zimbra/preact-router#3.1.0_base_path_support",
     "react-redux": "^7.2.2",
     "recompose": "^0.30.0",
-    "rimraf": "^3.0.2",
-    "moment": "^2.29.1"
+    "rimraf": "^3.0.2"
   },
   "license": "GPL-3.0",
   "dependencies": {

src/index.js

@@ -214,6 +214,7 @@ export function configure(env) {
 							require.resolve('@babel/plugin-proposal-export-namespace-from'),
 							require.resolve('@babel/plugin-proposal-export-default-from'),
 							require.resolve('@babel/plugin-transform-object-assign'),
+							require.resolve('@babel/plugin-proposal-optional-chaining'),
 							[require.resolve('@babel/plugin-transform-react-jsx'), { pragma: 'createElement' }]
 						]
 					}