perf(v2): use @babel/runtime plugin to reduce codesize (#2035)

packages/docusaurus/package.json

@@ -34,8 +34,10 @@
   "dependencies": {
     "@babel/core": "^7.7.2",
     "@babel/plugin-syntax-dynamic-import": "^7.2.0",
+    "@babel/plugin-transform-runtime": "^7.7.4",
     "@babel/preset-env": "^7.7.1",
     "@babel/preset-react": "^7.7.0",
+    "@babel/runtime": "^7.7.4",
     "@docusaurus/utils": "^2.0.0-alpha.36",
     "@endiliey/static-site-generator-webpack-plugin": "^4.0.0",
     "babel-loader": "^8.0.6",

packages/docusaurus/src/webpack/utils.ts

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import path from 'path';
 import MiniCssExtractPlugin from 'mini-css-extract-plugin';
 import env from 'std-env';
 import merge from 'webpack-merge';
@@ -83,6 +84,9 @@ export function getCacheLoader(
 }
 
 export function getBabelLoader(isServer: boolean, babelOptions?: {}): Loader {
+  const absoluteRuntimePath = path.dirname(
+    require.resolve(`@babel/runtime/package.json`),
+  );
   return {
     loader: require.resolve('babel-loader'),
     options: Object.assign(
@@ -116,6 +120,22 @@ export function getBabelLoader(isServer: boolean, babelOptions?: {}): Loader {
           '@babel/react',
         ],
         plugins: [
+          // Polyfills the runtime needed for async/await, generators, and friends
+          // https://babeljs.io/docs/en/babel-plugin-transform-runtime
+          [
+            '@babel/plugin-transform-runtime',
+            {
+              corejs: false,
+              helpers: true,
+              regenerator: true,
+              useESModules: true,
+              // Undocumented option that lets us encapsulate our runtime, ensuring
+              // the correct version is used
+              // https://github.com/babel/babel/blob/090c364a90fe73d36a30707fc612ce037bdbbb24/packages/babel-plugin-transform-runtime/src/index.js#L35-L42
+              absoluteRuntime: absoluteRuntimePath,
+            },
+          ],
+          // Adds syntax support for import()
           isServer ? 'dynamic-import-node' : '@babel/syntax-dynamic-import',
         ],
       },

yarn.lock

@@ -261,6 +261,13 @@
   dependencies:
     "@babel/types" "^7.7.0"
 
+"@babel/helper-module-imports@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/helper-module-imports/-/helper-module-imports-7.7.4.tgz#e5a92529f8888bf319a6376abfbd1cebc491ad91"
+  integrity sha512-dGcrX6K9l8258WFjyDLJwuVKxR4XZfU0/vTUgOQYWEnRD8mgr+p4d6fCUMq/ys0h4CCt/S5JhbvtyErjWouAUQ==
+  dependencies:
+    "@babel/types" "^7.7.4"
+
 "@babel/helper-module-transforms@^7.1.0":
   version "7.5.5"
   resolved "https://registry.yarnpkg.com/@babel/helper-module-transforms/-/helper-module-transforms-7.5.5.tgz#f84ff8a09038dcbca1fd4355661a500937165b4a"
@@ -817,6 +824,16 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-transform-runtime@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-transform-runtime/-/plugin-transform-runtime-7.7.4.tgz#51fe458c1c1fa98a8b07934f4ed38b6cd62177a6"
+  integrity sha512-O8kSkS5fP74Ad/8pfsCMGa8sBRdLxYoSReaARRNSz3FbFQj3z/QUvoUmJ28gn9BO93YfnXc3j+Xyaqe8cKDNBQ==
+  dependencies:
+    "@babel/helper-module-imports" "^7.7.4"
+    "@babel/helper-plugin-utils" "^7.0.0"
+    resolve "^1.8.1"
+    semver "^5.5.1"
+
 "@babel/plugin-transform-shorthand-properties@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-transform-shorthand-properties/-/plugin-transform-shorthand-properties-7.2.0.tgz#6333aee2f8d6ee7e28615457298934a3b46198f0"
@@ -988,6 +1005,13 @@
   dependencies:
     regenerator-runtime "^0.13.2"
 
+"@babel/runtime@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.7.4.tgz#b23a856751e4bf099262f867767889c0e3fe175b"
+  integrity sha512-r24eVUUr0QqNZa+qrImUk8fn5SPhHq+IfYvIoIMg0do3GdK9sMdiLKP3GYVVaxpPKORgm8KRKaNTEhAjgIpLMw==
+  dependencies:
+    regenerator-runtime "^0.13.2"
+
 "@babel/template@^7.1.0", "@babel/template@^7.4.4", "@babel/template@^7.6.0":
   version "7.6.0"
   resolved "https://registry.yarnpkg.com/@babel/template/-/template-7.6.0.tgz#7f0159c7f5012230dad64cca42ec9bdb5c9536e6"
@@ -1102,6 +1126,15 @@
     lodash "^4.17.13"
     to-fast-properties "^2.0.0"
 
+"@babel/types@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.7.4.tgz#516570d539e44ddf308c07569c258ff94fde9193"
+  integrity sha512-cz5Ji23KCi4T+YIE/BolWosrJuSmoZeN1EFnRtBwF+KKLi8GG/Z2c2hOJJeCXPk4mwk4QFvTmwIodJowXgttRA==
+  dependencies:
+    esutils "^2.0.2"
+    lodash "^4.17.13"
+    to-fast-properties "^2.0.0"
+
 "@cnakazawa/watch@^1.0.3":
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/@cnakazawa/watch/-/watch-1.0.3.tgz#099139eaec7ebf07a27c1786a3ff64f39464d2ef"
@@ -14075,6 +14108,13 @@ resolve@^1.11.0, resolve@^1.12.0, resolve@^1.3.2:
   dependencies:
     path-parse "^1.0.6"
 
+resolve@^1.8.1:
+  version "1.12.2"
+  resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.12.2.tgz#08b12496d9aa8659c75f534a8f05f0d892fff594"
+  integrity sha512-cAVTI2VLHWYsGOirfeYVVQ7ZDejtQ9fp4YhYckWDEkFfqbVjaT11iM8k6xSAfGFMM+gDpZjMnFssPu8we+mqFw==
+  dependencies:
+    path-parse "^1.0.6"
+
 responselike@1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/responselike/-/responselike-1.0.2.tgz#918720ef3b631c5642be068f15ade5a46f4ba1e7"