migrate @babel/preset-env to babel-preset-modules (#24780)

* modern preset * switch language_out to be NO_TRANSPILE when esm flag is used * fix formatting issue
ampproject · Sep 30, 2019 · 587f0b4 · 587f0b4
1 parent 8370cee
commit 587f0b4
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Showing 6 changed files with 34 additions and 17 deletions.
diff --git a/babel.config.js b/babel.config.js
@@ -37,10 +37,6 @@ const noModuleTarget = {
     : ['Last 2 versions'],
 };
 
-const moduleTarget = {
-  'esmodules': true,
-};
-
 // eslint-disable-next-line local/no-module-exports
 module.exports = function(api) {
   api.cache(true);
@@ -51,14 +47,21 @@ module.exports = function(api) {
   }
   return {
     'presets': [
-      [
-        '@babel/preset-env',
-        {
-          'modules': isDist ? false : 'commonjs',
-          'loose': true,
-          'targets': esm ? moduleTarget : noModuleTarget,
-        },
-      ],
+      esm
+        ? [
+            'babel-preset-modules',
+            {
+              'loose': true,
+            },
+          ]
+        : [
+            '@babel/preset-env',
+            {
+              'modules': isDist ? false : 'commonjs',
+              'loose': true,
+              'targets': noModuleTarget,
+            },
+          ],
     ],
     'compact': false,
     'sourceType': 'module',

diff --git a/build-system/compile/compile.js b/build-system/compile/compile.js
@@ -256,7 +256,7 @@ function compile(entryModuleFilenames, outputDir, outputFilename, options) {
       assume_function_wrapper: true,
       // Transpile from ES6 to ES5 if not running with `--esm`
       // otherwise transpilation is done by Babel
-      language_in: 'ECMASCRIPT6',
+      language_in: argv.esm ? 'ECMASCRIPT_2017' : 'ECMASCRIPT6',
       language_out: argv.esm ? 'NO_TRANSPILE' : 'ECMASCRIPT5',
       // We do not use the polyfills provided by closure compiler.
       // If you need a polyfill. Manually include them in the

diff --git a/build-system/compile/single-pass.js b/build-system/compile/single-pass.js
@@ -105,14 +105,16 @@ exports.getFlags = function(config) {
     source_map_include_content: !!argv.full_sourcemaps,
     source_map_location_mapping: ['|/'],
     //new_type_inf: true,
-    language_in: 'ES6',
     // By default closure puts all of the public exports on the global, but
     // because of the wrapper modules (to mitigate async loading of scripts)
     // that we add to the js binaries this prevents other js binaries from
     // accessing the symbol, we remedy this by attaching all public exports
     // to `_` and everything imported across modules is is accessed through `_`.
     rename_prefix_namespace: '_',
-    language_out: config.language_out || 'ES5',
+    language_in: config.esm ? 'ECMASCRIPT_2017' : 'ECMASCRIPT6',
+    language_out: config.esm
+      ? 'NO_TRANSPILE'
+      : config.language_out || 'ECMASCRIPT5',
     chunk_output_path_prefix: config.writeTo || 'out/',
     module_resolution: 'NODE',
     process_common_js_modules: true,
@@ -551,6 +553,7 @@ exports.singlePassCompile = async function(entryModule, options) {
     .getFlags({
       modules: [entryModule].concat(extensions),
       writeTo: singlePassDest,
+      esm: options.esm,
       define: options.define,
       externs: options.externs,
       hideWarningsFor: options.hideWarningsFor,

diff --git a/build-system/typescript.js b/build-system/typescript.js
@@ -36,8 +36,8 @@ exports.transpileTs = function(srcDir, srcFilename) {
   const tsEntry = path.join(srcDir, srcFilename).replace(/\.js$/, '.ts');
   const tsConfig = ts.convertCompilerOptionsFromJson(
     {
-      'module': 'ES6',
-      'target': 'ES6',
+      'module': 'esnext',
+      'target': 'esnext',
     },
     srcDir
   );

diff --git a/package.json b/package.json
@@ -20,6 +20,7 @@
   "dependencies": {
     "@ampproject/animations": "0.2.0",
     "@ampproject/worker-dom": "0.19.0",
+    "babel-preset-modules": "0.0.2",
     "document-register-element": "1.5.0",
     "dompurify": "2.0.2",
     "moment": "2.24.0",

diff --git a/yarn.lock b/yarn.lock
@@ -2703,6 +2703,16 @@ babel-preset-jest@^24.9.0:
     "@babel/plugin-syntax-object-rest-spread" "^7.0.0"
     babel-plugin-jest-hoist "^24.9.0"
 
+babel-preset-modules@0.0.2:
+  version "0.0.2"
+  resolved "https://registry.yarnpkg.com/babel-preset-modules/-/babel-preset-modules-0.0.2.tgz#3ece9871bb022784a76749114e7b8bb109a6ec1e"
+  integrity sha512-YWjLfgPRGrQNPEZITnyIgsMITrPjA4ZvLS6hVyTCYgqymR0+l2P1jTd3lMHZ+hBDqAHDSGGKD20oxUmQvvvubg==
+  dependencies:
+    "@babel/plugin-proposal-unicode-property-regex" "^7.4.4"
+    "@babel/plugin-transform-dotall-regex" "^7.4.4"
+    "@babel/types" "^7.4.4"
+    esutils "^2.0.2"
+
 babel-runtime@^6.22.0, babel-runtime@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.26.0.tgz#965c7058668e82b55d7bfe04ff2337bc8b5647fe"