Adding Babel filter import to remove unwanted fetch polyfill (ampproj…

…ect#18494)

* adding plugin to remove fetch polyfill

* adding babel plugins

* fix lint

* passing options through and through

* fixing path for esm build

* consolidating plugin logic

* fixing shas

* readding plugin

* removing all polyfills

* fixing package lock

* fixing yarn lock

build-system/build.conf.js

@@ -14,10 +14,27 @@
  * limitations under the License.
  */
 
+const defaultPlugins = [
+  require.resolve(
+      './babel-plugins/babel-plugin-transform-parenthesize-expression'),
+];
 
 module.exports = {
-  plugins: [
-    require.resolve(
-        './babel-plugins/babel-plugin-transform-parenthesize-expression'),
-  ],
+  plugins: isEsmBuild => {
+    if (isEsmBuild) {
+      return defaultPlugins.concat([
+        [require.resolve('babel-plugin-filter-imports'), {
+          'imports': {
+            './polyfills/fetch': ['installFetch'],
+            './polyfills/domtokenlist-toggle': ['installDOMTokenListToggle'],
+            './polyfills/document-contains': ['installDocContains'],
+            './polyfills/math-sign': ['installMathSign'],
+            './polyfills/object-assign': ['installObjectAssign'],
+            './polyfills/promise': ['installPromise'],
+          },
+        }],
+      ]);
+    }
+    return defaultPlugins;
+  },
 };

build-system/get-dep-graph.js

@@ -80,7 +80,7 @@ exports.getFlags = function(config) {
     ],
     //new_type_inf: true,
     language_in: 'ES6',
-    language_out: 'ES5',
+    language_out: config.language_out || 'ES5',
     module_output_path_prefix: config.writeTo || 'out/',
     externs: config.externs,
     define: config.define,
@@ -305,7 +305,7 @@ exports.getGraph = function(entryModules, config) {
     graph.sorted = Array.from(topo.sort().keys()).reverse();
 
     setupBundles(graph);
-    transformPathsToTempDir(graph);
+    transformPathsToTempDir(graph, config);
     resolve(graph);
     fs.writeFileSync('deps.txt', JSON.stringify(graph, null, 2));
   }).on('error', reject).pipe(devnull());
@@ -377,8 +377,9 @@ function setupBundles(graph) {
  * to a temporary directory where we can run babel transformations.
  *
  * @param {!Object} graph
+ * @param {!Object} config
  */
-function transformPathsToTempDir(graph) {
+function transformPathsToTempDir(graph, config) {
   console/*OK*/.log(colors.green(`temp directory ${graph.tmp}`));
   // `sorted` will always have the files that we need.
   graph.sorted.forEach(f => {
@@ -387,7 +388,7 @@ function transformPathsToTempDir(graph) {
       fs.copySync(f, `${graph.tmp}/${f}`);
     } else {
       const {code} = babel.transformFileSync(f, {
-        plugins: conf.plugins,
+        plugins: conf.plugins(config.define.indexOf['ESM_BUILD=true'] !== -1),
         babelrc: false,
         retainLines: true,
       });

build-system/tasks/compile.js

@@ -130,12 +130,23 @@ function compile(entryModuleFilenames, outputDir,
     define.push('FORTESTING=true');
   }
   if (options.singlePassCompilation) {
-    // TODO(@cramforce): Run the post processing step
-    return singlePassCompile(entryModuleFilenames, {
+    const compilationOptions = {
       define,
       externs: baseExterns,
       hideWarningsFor,
-    }).then(() => {
+    };
+
+    // Add babel plugin to remove unwanted polyfills in esm build
+    if (options.esmPassCompilation) {
+      compilationOptions['dest'] = './dist/esm/';
+      define.push('ESM_BUILD=true');
+    }
+
+    // TODO(@cramforce): Run the post processing step
+    return singlePassCompile(
+        entryModuleFilenames,
+        compilationOptions
+    ).then(() => {
       return new Promise((resolve, reject) => {
         const stream = gulp.src(outputDir + '/**/*.js');
         stream.on('end', resolve);

gulpfile.js

@@ -375,6 +375,7 @@ function compile(watch, shouldMinify, opt_preventRemoveAndMakeDir,
       minify: shouldMinify,
       wrapper: wrappers.mainBinary,
       singlePassCompilation: argv.single_pass,
+      esmPassCompilation: argv.esm,
     }),
     compileJs('./extensions/amp-viewer-integration/0.1/examples/',
         'amp-viewer-host.js', './dist/v0/examples', {

package.json

@@ -46,6 +46,7 @@
     "ava": "0.25.0",
     "babel-core": "6.26.3",
     "babel-eslint": "10.0.1",
+    "babel-plugin-filter-imports": "^2.0.3",
     "babel-plugin-istanbul": "5.0.1",
     "babel-plugin-transform-es2015-modules-commonjs": "6.26.2",
     "babel-plugin-transform-remove-strict-mode": "0.0.2",

yarn.lock

@@ -1633,6 +1633,14 @@ babel-plugin-espower@^2.3.2:
     espurify "^1.6.0"
     estraverse "^4.1.1"
 
+babel-plugin-filter-imports@^2.0.3:
+  version "2.0.3"
+  resolved "https://registry.yarnpkg.com/babel-plugin-filter-imports/-/babel-plugin-filter-imports-2.0.3.tgz#21f2773d0d74558986dd7af89f6f753d5fa92da3"
+  integrity sha512-s2vbul45NHOI665jcJvvIdzZLMIKgUdhofGEbxXn7GxfEB6SePCUbj2qBPjV9oqHuYBQucih/tRhO/GJu8mPkg==
+  dependencies:
+    "@babel/types" "^7.0.0"
+    lodash "^4.17.11"
+
 [email protected]:
   version "5.0.1"
   resolved "https://registry.yarnpkg.com/babel-plugin-istanbul/-/babel-plugin-istanbul-5.0.1.tgz#2ce7bf211f0d9480ff7fd294bd05e2fa555e31ea"
@@ -10034,6 +10042,11 @@ lodash@^4.17.10, lodash@^4.17.5:
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
   integrity sha512-UejweD1pDoXu+AD825lWwp4ZGtSwgnpZxb3JDViD7StjQz+Nb/6l093lx4OQ0foGWNRoc19mWy7BzL+UAK2iVg==
 
+lodash@^4.17.11:
+  version "4.17.11"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
+  integrity sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==
+
 lodash@~1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-1.0.2.tgz#8f57560c83b59fc270bd3d561b690043430e2551"