From ad4fbba7385597dbc394fe59b0e54d576013681c Mon Sep 17 00:00:00 2001
From: Christopher Hiller <boneskull@boneskull.com>
Date: Mon, 14 Sep 2020 16:28:04 -0700
Subject: [PATCH] do not leak polyfills into global context; closes #4423

---
 package-lock.json | 44 ++++++++++++++++++++++++++++++++++++++++++++
 package.json      |  3 ++-
 rollup.config.js  | 18 +++---------------
 3 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 12ccfc1fb7..562c6bed02 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2757,6 +2757,26 @@
         "@babel/helper-plugin-utils": "^7.10.4"
       }
     },
+    "@babel/plugin-transform-runtime": {
+      "version": "7.11.5",
+      "resolved": "https://registry.npmjs.org/@babel/plugin-transform-runtime/-/plugin-transform-runtime-7.11.5.tgz",
+      "integrity": "sha512-9aIoee+EhjySZ6vY5hnLjigHzunBlscx9ANKutkeWTJTx6m5Rbq6Ic01tLvO54lSusR+BxV7u4UDdCmXv5aagg==",
+      "dev": true,
+      "requires": {
+        "@babel/helper-module-imports": "^7.10.4",
+        "@babel/helper-plugin-utils": "^7.10.4",
+        "resolve": "^1.8.1",
+        "semver": "^5.5.1"
+      },
+      "dependencies": {
+        "semver": {
+          "version": "5.7.1",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
+          "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
+          "dev": true
+        }
+      }
+    },
     "@babel/plugin-transform-shorthand-properties": {
       "version": "7.10.4",
       "resolved": "https://registry.npmjs.org/@babel/plugin-transform-shorthand-properties/-/plugin-transform-shorthand-properties-7.10.4.tgz",
@@ -2997,6 +3017,24 @@
         }
       }
     },
+    "@babel/runtime-corejs3": {
+      "version": "7.11.2",
+      "resolved": "https://registry.npmjs.org/@babel/runtime-corejs3/-/runtime-corejs3-7.11.2.tgz",
+      "integrity": "sha512-qh5IR+8VgFz83VBa6OkaET6uN/mJOhHONuy3m1sgF0CV6mXdPSEBdA7e1eUbVvyNtANjMbg22JUv71BaDXLY6A==",
+      "dev": true,
+      "requires": {
+        "core-js-pure": "^3.0.0",
+        "regenerator-runtime": "^0.13.4"
+      },
+      "dependencies": {
+        "regenerator-runtime": {
+          "version": "0.13.7",
+          "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.13.7.tgz",
+          "integrity": "sha512-a54FxoJDIr27pgf7IgeQGxmqUNYrcV338lf/6gH456HZ/PhX+5BcwHXG9ajESmwe6WRO0tAzRUrRmNONWgkrew==",
+          "dev": true
+        }
+      }
+    },
     "@babel/template": {
       "version": "7.8.6",
       "resolved": "https://registry.npmjs.org/@babel/template/-/template-7.8.6.tgz",
@@ -7281,6 +7319,12 @@
         }
       }
     },
+    "core-js-pure": {
+      "version": "3.6.5",
+      "resolved": "https://registry.npmjs.org/core-js-pure/-/core-js-pure-3.6.5.tgz",
+      "integrity": "sha512-lacdXOimsiD0QyNf9BC/mxivNJ/ybBGJXQFKzRekp1WTHoVUWsUHEn+2T8GJAzzIhyOuXA+gOxCVN3l+5PLPUA==",
+      "dev": true
+    },
     "core-util-is": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz",
diff --git a/package.json b/package.json
index 5853a92d19..7bf21de03a 100644
--- a/package.json
+++ b/package.json
@@ -79,7 +79,9 @@
   "devDependencies": {
     "@11ty/eleventy": "^0.11.0",
     "@11ty/eleventy-plugin-inclusive-language": "^1.0.0",
+    "@babel/plugin-transform-runtime": "^7.11.5",
     "@babel/preset-env": "^7.11.0",
+    "@babel/runtime-corejs3": "^7.11.2",
     "@mocha/docdash": "^3.0.1",
     "@rollup/plugin-babel": "^5.1.0",
     "@rollup/plugin-commonjs": "^14.0.0",
@@ -93,7 +95,6 @@
     "chai": "^4.2.0",
     "coffee-script": "^1.12.7",
     "configstore": "^5.0.1",
-    "core-js": "^3.6.5",
     "coveralls": "^3.1.0",
     "cross-env": "^7.0.2",
     "cross-spawn": "^7.0.3",
diff --git a/rollup.config.js b/rollup.config.js
index 4b4f3494e4..0086d64db3 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -32,21 +32,9 @@ const config = {
     }),
     babel({
       exclude: /core-js/,
-      presets: [
-        [
-          '@babel/preset-env',
-          {
-            modules: false,
-            useBuiltIns: 'usage',
-            forceAllTransforms: true,
-            corejs: {
-              version: 3,
-              proposals: false
-            }
-          }
-        ]
-      ],
-      babelHelpers: 'bundled'
+      presets: [['@babel/preset-env', {modules: false}]],
+      plugins: [['@babel/plugin-transform-runtime', {corejs: 3}]],
+      babelHelpers: 'runtime'
     })
   ],
   onwarn: (warning, warn) => {