Parallelize inject-babel-helpers plugin

lib/index.js

@@ -7,7 +7,7 @@ const resolve = require('resolve');
 const concatBundle = require('./concat-bundle');
 const buildDebugMacroPlugin = require('./build-debug-macro-plugin');
 const buildStripClassCallcheckPlugin = require('./build-strip-class-callcheck-plugin');
-const injectBabelHelpers = require('./transforms/inject-babel-helpers');
+const injectBabelHelpers = require('./transforms/inject-babel-helpers').injectBabelHelpers;
 const debugTree = require('broccoli-debug').buildDebugCallback('ember-source:addon');
 
 const PRE_BUILT_TARGETS = [
@@ -138,6 +138,7 @@ module.exports = {
     // We want to enable async/generator helpers if we are developing locally,
     // but not for any other project.
     let isEmberSource = this.project.name() === 'ember-source';
+    let babelHelperPlugin = injectBabelHelpers(isEmberSource);
 
     let options = {
       'ember-cli-babel': {
@@ -147,7 +148,7 @@ module.exports = {
       babel: Object.assign({}, babelOptions, {
         loose: true,
         plugins: [
-          injectBabelHelpers(isEmberSource),
+          babelHelperPlugin,
           buildDebugMacroPlugin(!isProduction),
           [
             require.resolve('@babel/plugin-transform-block-scoping'),

lib/transforms/inject-babel-helpers.js

@@ -3,29 +3,39 @@
 const { addNamed } = require('@babel/helper-module-imports');
 
 function injectBabelHelpers(isEmberSource = false) {
-  function injectBabelHelpersPlugin() {
-    return {
-      pre(file) {
-        file.set('helperGenerator', function(name) {
-          if (name === 'extends') {
-            return addNamed(file.path, 'assign', '@ember/polyfills');
-          } else if (isEmberSource && name === 'asyncToGenerator') {
-            // Returning a falsy value will cause the helper to be inlined,
-            // which is fine for local tests
-            return false;
-          }
-
-          return addNamed(file.path, name, 'ember-babel');
-        });
-      },
-    };
-  }
+  let helperplugin = injectBabelHelpersPlugin;
+  helperplugin._parallelBabel = {
+    requireFile: __filename,
+    buildUsing: 'injectBabelHelpersPlugin',
+    params: { isEmberSource },
+  };
 
-  injectBabelHelpersPlugin.baseDir = function() {
+  helperplugin.baseDir = function() {
     return 'babel-core';
   };
 
-  return injectBabelHelpersPlugin;
+  return helperplugin;
+}
+
+function injectBabelHelpersPlugin(isEmberSource) {
+  return {
+    pre(file) {
+      file.set('helperGenerator', function(name) {
+        if (name === 'extends') {
+          return addNamed(file.path, 'assign', '@ember/polyfills');
+        } else if (isEmberSource && name === 'asyncToGenerator') {
+          // Returning a falsy value will cause the helper to be inlined,
+          // which is fine for local tests
+          return false;
+        }
+
+        return addNamed(file.path, name, 'ember-babel');
+      });
+    },
+  };
 }
 
-module.exports = injectBabelHelpers;
+module.exports = {
+  injectBabelHelpers,
+  injectBabelHelpersPlugin,
+};