Update babel en disable ES5 builds on dev (#4876)

build-scripts/babel.js

@@ -34,6 +34,7 @@ module.exports.babelLoaderConfig = ({ latestBuild }) => {
             },
           ],
           "@babel/plugin-proposal-optional-chaining",
+          "@babel/plugin-proposal-nullish-coalescing-operator",
           [
             require("@babel/plugin-proposal-decorators").default,
             { decoratorsBeforeExport: true },

build-scripts/gulp/webpack.js

@@ -57,7 +57,7 @@ const handler = (done) => (err, stats) => {
 
 gulp.task("webpack-watch-app", () => {
   // we are not calling done, so this command will run forever
-  webpack(bothBuilds(createAppConfig, { isProdBuild: false })).watch(
+  webpack(createAppConfig({ isProdBuild: false, latestBuild: true })).watch(
     {},
     handler()
   );

package.json

@@ -109,16 +109,17 @@
     "xss": "^1.0.6"
   },
   "devDependencies": {
-    "@babel/core": "^7.7.4",
-    "@babel/plugin-external-helpers": "^7.7.4",
-    "@babel/plugin-proposal-class-properties": "^7.7.4",
-    "@babel/plugin-proposal-decorators": "^7.7.4",
-    "@babel/plugin-proposal-object-rest-spread": "^7.7.4",
-    "@babel/plugin-proposal-optional-chaining": "^7.7.4",
-    "@babel/plugin-syntax-dynamic-import": "^7.7.4",
-    "@babel/plugin-transform-react-jsx": "^7.7.4",
-    "@babel/preset-env": "^7.7.4",
-    "@babel/preset-typescript": "^7.7.4",
+    "@babel/core": "^7.8.4",
+    "@babel/plugin-external-helpers": "^7.8.3",
+    "@babel/plugin-proposal-class-properties": "^7.8.3",
+    "@babel/plugin-proposal-decorators": "^7.8.3",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.8.3",
+    "@babel/plugin-proposal-object-rest-spread": "^7.8.3",
+    "@babel/plugin-proposal-optional-chaining": "^7.8.3",
+    "@babel/plugin-syntax-dynamic-import": "^7.8.3",
+    "@babel/plugin-transform-react-jsx": "^7.8.3",
+    "@babel/preset-env": "^7.8.4",
+    "@babel/preset-typescript": "^7.8.3",
     "@types/chai": "^4.1.7",
     "@types/chromecast-caf-receiver": "^3.0.12",
     "@types/chromecast-caf-sender": "^1.0.1",