metro-bundler: transform import() to basic require()

Reviewed By: mjesun

Differential Revision: D5631078

fbshipit-source-id: a8d4955a723c1846b9406e734c3e3fa2c0df3fb7

babel-preset/configs/main.js

@@ -21,7 +21,6 @@ const getPreset = (src, options) => {
 
   plugins.push(
     'syntax-class-properties',
-    'syntax-dynamic-import',
     'syntax-trailing-function-commas',
     'transform-class-properties',
     'transform-es2015-block-scoping',
@@ -76,6 +75,9 @@ const getPreset = (src, options) => {
   ) {
     plugins.push('transform-react-display-name');
   }
+  if (isNull || src.indexOf('import(')) {
+    plugins.push(require('../transforms/transform-dynamic-import'));
+  }
 
   if (options && options.dev) {
     plugins.push('transform-react-jsx-source');

babel-preset/package.json

@@ -44,6 +44,7 @@
     "babel-plugin-transform-react-jsx-source": "^6.5.0",
     "babel-plugin-transform-react-jsx": "^6.5.0",
     "babel-plugin-transform-regenerator": "^6.5.0",
+    "babel-template": "^6.24.1",
     "react-transform-hmr": "^1.0.4"
   }
 }

babel-preset/transforms/transform-dynamic-import.js

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) 2016-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.
+ */
+
+'use strict';
+
+const template = require('babel-template');
+
+const buildImport = template('Promise.resolve().then(() => require(ARGS))');
+
+const TYPE_IMPORT = 'Import';
+
+const plugin = {
+  inherits: require('babel-plugin-syntax-dynamic-import'),
+
+  visitor: {
+    CallExpression(path) {
+      if (path.node.callee.type !== TYPE_IMPORT) {
+        return;
+      }
+      const newImport = buildImport({ARGS: path.node.arguments});
+      path.replaceWith(newImport);
+    },
+  },
+};
+
+module.exports = plugin;