Convert System.import transform to babel 6

Reviewed By: martinbigio

Differential Revision: D2615286

fb-gh-sync-id: 4f0e8e3359413d972ab4d0da291870768a77e361

packager/react-packager/src/transforms/babel-plugin-system-import/6/index.js

@@ -0,0 +1,63 @@
+ /**
+  * Copyright (c) 2015-present, Facebook, Inc.
+  * All rights reserved.
+  *
+  * This source code is licensed under the BSD-style license found in the
+  * LICENSE file in the root directory of this source tree. An additional grant
+  * of patent rights can be found in the PATENTS file in the same directory.
+  *
+  */
+/*jslint node: true */
+'use strict';
+
+const t = require('babel-types');
+
+/**
+ * Transforms asynchronous module importing into a function call
+ * that includes which bundle needs to be loaded
+ *
+ * Transforms:
+ *
+ *  System.import('moduleA')
+ *
+ * to:
+ *
+ *  loadBundles('bundleA')
+ */
+module.exports = function() {
+  return {
+    visitor: {
+      CallExpression: function (path, state) {
+        if (!isAppropriateSystemImportCall(path.node)) {
+          return;
+        }
+
+        var bundlesLayout = state.opts.bundlesLayout;
+        var bundleID = bundlesLayout.getBundleIDForModule(
+          path.node.arguments[0].value
+        );
+
+        var bundles = bundleID.split('.');
+        bundles.splice(0, 1);
+        bundles = bundles.map(function(id) {
+          return t.stringLiteral('bundle.' + id);
+        });
+
+        path.replaceWith(t.callExpression(
+          t.identifier('loadBundles'),
+          [t.arrayExpression(bundles)]
+        ));
+      },
+    },
+  };
+};
+
+function isAppropriateSystemImportCall(node) {
+  return (
+    node.callee.type === 'MemberExpression' &&
+    node.callee.object.name === 'System' &&
+    node.callee.property.name === 'import' &&
+    node.arguments.length === 1 &&
+    node.arguments[0].type === 'StringLiteral'
+  );
+}