fix: switch to core-js@2 until @babel/polyfill update

Author: gregberge

packages/smooth/package.json

@@ -55,7 +55,7 @@
     "babel-loader": "^8.0.5",
     "camelcase": "^5.3.1",
     "commander": "^2.20.0",
-    "core-js": "^3.0.1",
+    "core-js": "^2.6.5",
     "cors": "^2.8.5",
     "cwd": "^0.10.0",
     "errorhandler": "^1.5.0",

packages/smooth/src/babel/preset.js

@@ -15,7 +15,7 @@ const nodeConfig = opts => ({
       {
         loose: true,
         useBuiltIns: 'entry',
-        corejs: 'core-js@3',
+        corejs: 'core-js@2',
         targets: {
           node: 'current',
         },
@@ -35,7 +35,7 @@ const webConfig = opts => ({
         modules: false,
         loose: true,
         useBuiltIns: 'entry',
-        corejs: 'core-js@3',
+        corejs: 'core-js@2',
         ...opts['preset-env'],
       },
     ],

yarn.lock

@@ -4020,10 +4020,10 @@ core-js@^1.0.0:
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-1.2.7.tgz#652294c14651db28fa93bd2d5ff2983a4f08c636"
   integrity sha1-ZSKUwUZR2yj6k70tX/KYOk8IxjY=
 
-core-js@^3.0.1:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.0.1.tgz#1343182634298f7f38622f95e73f54e48ddf4738"
-  integrity sha512-sco40rF+2KlE0ROMvydjkrVMMG1vYilP2ALoRXcYR4obqbYIuV3Bg+51GEDW+HF8n7NRA+iaA4qD0nD9lo9mew==
+core-js@^2.6.5:
+  version "2.6.5"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.5.tgz#44bc8d249e7fb2ff5d00e0341a7ffb94fbf67895"
+  integrity sha512-klh/kDpwX8hryYL14M9w/xei6vrv6sE8gTHDG7/T/+SEovB/G4ejwcfE/CBzO6Edsu+OETZMZ3wcX/EjUkrl5A==
 
 core-util-is@1.0.2, core-util-is@~1.0.0:
   version "1.0.2"