From 6a35aa7ac67a66a59d3999889400cbd3a99310b4 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sat, 9 Nov 2019 14:17:07 +0800
Subject: [PATCH 1/2] merge fisker:corejs-support

---
 cspell.json              |  1 +
 package.json             |  1 +
 scripts/build/bundler.js | 33 ++++++++++++++++++++++++++++-----
 scripts/build/config.js  |  1 +
 yarn.lock                |  5 +++++
 5 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/cspell.json b/cspell.json
index 2dcef816911a..5ee054463707 100644
--- a/cspell.json
+++ b/cspell.json
@@ -61,6 +61,7 @@
         "codemirror",
         "codemod",
         "codemods",
+        "corejs",
         "combinator",
         "commonmark",
         "concating",
diff --git a/package.json b/package.json
index 892631d09cc8..d3664782e07c 100644
--- a/package.json
+++ b/package.json
@@ -82,6 +82,7 @@
     "benchmark": "2.1.4",
     "builtin-modules": "3.1.0",
     "codecov": "3.6.1",
+    "core-js": "3.4.0",
     "cross-env": "6.0.3",
     "eslint": "6.6.0",
     "eslint-config-prettier": "6.5.0",
diff --git a/scripts/build/bundler.js b/scripts/build/bundler.js
index 7cdc86387a16..bf99ff5febf3 100644
--- a/scripts/build/bundler.js
+++ b/scripts/build/bundler.js
@@ -40,21 +40,40 @@ function getBabelConfig(bundle) {
   const config = {
     babelrc: false,
     plugins: bundle.babelPlugins || [],
+    exclude: [],
     compact: bundle.type === "plugin" ? false : "auto"
   };
+  const presetEnvConfig = {
+    targets: {
+      node: "4"
+    },
+    modules: false
+  };
   if (bundle.type === "core") {
     config.plugins.push(
       require.resolve("./babel-plugins/transform-custom-require")
     );
+
+    if (bundle.corejs) {
+      Object.assign(presetEnvConfig, {
+        useBuiltIns: "usage",
+        corejs: {
+          version: 3,
+          proposals: true
+        }
+      });
+      config.exclude.push(/\/core-js\//);
+    }
   }
-  const targets = { node: 4 };
   if (bundle.target === "universal") {
     // From https://jamie.build/last-2-versions
-    targets.browsers = [">0.25%", "not ie 11", "not op_mini all"];
+    presetEnvConfig.targets.browsers = [
+      ">0.25%",
+      "not ie 11",
+      "not op_mini all"
+    ];
   }
-  config.presets = [
-    [require.resolve("@babel/preset-env"), { targets, modules: false }]
-  ];
+  config.presets = [[require.resolve("@babel/preset-env"), presetEnvConfig]];
   return config;
 }
 
@@ -206,6 +225,10 @@ function runWebpack(config) {
 }
 
 module.exports = async function createBundle(bundle, cache) {
+  if (bundle.corejs && bundle.type !== "core") {
+    throw new Error("Only core bundles can use corejs");
+  }
+
   const inputOptions = getRollupConfig(bundle);
   const outputOptions = getRollupOutputOptions(bundle);
 
diff --git a/scripts/build/config.js b/scripts/build/config.js
index bacf937871f1..62009c11fdad 100644
--- a/scripts/build/config.js
+++ b/scripts/build/config.js
@@ -19,6 +19,7 @@ const babelReplaceArrayIncludesWithIndexof = require.resolve(
  * @property {Object.<string, string>} replace - map of strings to replace when processing the bundle
  * @property {string[]} babelPlugins - babel plugins
  * @property {Object?} terserOptions - options for `terser`
+ * @property {boolean?} corejs - use corejs for `@babel/preset-env`
 
  * @typedef {Object} CommonJSConfig
  * @property {Object} namedExports - for cases where rollup can't infer what's exported
diff --git a/yarn.lock b/yarn.lock
index cb575cf966df..7ea3470d8fd7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1991,6 +1991,11 @@ core-js-pure@3.1.3:
   resolved "https://registry.yarnpkg.com/core-js-pure/-/core-js-pure-3.1.3.tgz#4c90752d5b9471f641514f3728f51c1e0783d0b5"
   integrity sha512-k3JWTrcQBKqjkjI0bkfXS0lbpWPxYuHWfMMjC1VDmzU4Q58IwSbuXSo99YO/hUHlw/EB4AlfA2PVxOGkrIq6dA==
 
+core-js@3.4.0:
+  version "3.4.0"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.4.0.tgz#29ea478601789c72f2978e9bb98f43546f89d3aa"
+  integrity sha512-lQxb4HScV71YugF/X28LtePZj9AB7WqOpcB+YztYxusvhrgZiQXPmCYfPC5LHsw/+ScEtDbXU3xbqH3CjBRmYA==
+
 core-js@^2.4.0, core-js@^2.5.0:
   version "2.5.1"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.5.1.tgz#ae6874dc66937789b80754ff5428df66819ca50b"

From b44d40511a8ef025c1a397f3ffec1929f406b625 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sat, 9 Nov 2019 14:18:18 +0800
Subject: [PATCH 2/2] Enable `corejs` option for core bundle `bin-prettier.js`
 and `third-party.js`

---
 scripts/build/config.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/build/config.js b/scripts/build/config.js
index 62009c11fdad..fe03bbcc4e1c 100644
--- a/scripts/build/config.js
+++ b/scripts/build/config.js
@@ -173,12 +173,14 @@ const coreBundles = [
     input: "bin/prettier.js",
     type: "core",
     output: "bin-prettier.js",
+    corejs: true,
     target: "node",
     externals: [path.resolve("src/common/third-party.js")]
   },
   {
     input: "src/common/third-party.js",
     type: "core",
+    corejs: true,
     target: "node",
     replace: {
       // cosmiconfig@5 -> import-fresh uses `require` to resolve js config, which caused Error: