Switch to core-js for polyfills

babel.config.json

@@ -2,6 +2,8 @@
   "presets": [
     [
       "@babel/preset-env", {
+        "useBuiltIns": "usage",
+        "corejs": 3,
         "modules": false
       }
     ]

config/rollup.config.legacy.js

@@ -29,7 +29,9 @@ export default {
     commonjs(),
     json({ indent: '' }),
     babel({
-      babelHelpers: 'bundled'
+      babelHelpers: 'bundled',
+      // avoid circular dependencies due to `useBuiltIns: usage` option
+      exclude: [/\/core-js\//]
     })
   ]
 };

modules/id.js

@@ -1,10 +1,12 @@
-import 'browser-polyfills';
-import 'es6-symbol/implement';
+// polyfills newer JS functionality for older browsers
+import 'core-js/stable';
 import 'regenerator-runtime/runtime';
-import 'string.fromcodepoint/auto';
+
+// polyfill window.fetch and AbortController (not included in core-js)
+import 'whatwg-fetch';
 import 'abortcontroller-polyfill/dist/polyfill-patch-fetch';
 
-// polyfill requestIdleCallback
+// polyfill idle callback functions (not included in core-js)
 window.requestIdleCallback = window.requestIdleCallback ||
     function(cb) {
         var start = Date.now();
@@ -17,7 +19,6 @@ window.requestIdleCallback = window.requestIdleCallback ||
             });
         });
     };
-
 window.cancelIdleCallback = window.cancelIdleCallback ||
     function(id) {
         window.cancelAnimationFrame(id);

package.json

@@ -50,9 +50,8 @@
     "abortcontroller-polyfill": "^1.4.0",
     "aes-js": "^3.1.2",
     "alif-toolkit": "^1.2.9",
-    "browser-polyfills": "~1.5.0",
+    "core-js": "^3.6.5",
     "diacritics": "1.3.0",
-    "es6-symbol": "^3.1.3",
     "fast-deep-equal": "~3.1.1",
     "fast-json-stable-stringify": "2.1.0",
     "lodash-es": "~4.17.15",
@@ -63,7 +62,7 @@
     "pannellum": "2.5.6",
     "rbush": "3.0.1",
     "regenerator-runtime": "^0.13.7",
-    "string.fromcodepoint": "1.0.0",
+    "whatwg-fetch": "^3.4.1",
     "which-polygon": "2.2.0"
   },
   "devDependencies": {