Add possibility to add custom plugin prefix

Summary: The problem with a fixed prefix is that babel 7 uses a scoped packages and every (standard) plugin is now part of that scope so the prefix is no longer `babel-plugin-` but instead `babel/plugin-`. There are more changes. This one will at least fix most of them.

Reviewed By: davidaurelio

Differential Revision: D7085102

fbshipit-source-id: b927998c611b71b3265e1cb3f6df537b14f9cb25

Author: Peter van der Zee

Diff for: babel-preset/lib/resolvePlugins.js

@@ -3,6 +3,8 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
+ *
+ * @format
  */
 'use strict';
 
@@ -12,25 +14,29 @@
  * the file it's compiling. This makes sure that we're using the plugins
  * installed in the react-native package.
  */
-function resolvePlugins(plugins) {
-  return plugins.map(resolvePlugin);
+function resolvePlugins(plugins, prefix) {
+  return plugins.map(plugin => resolvePlugin(plugin, prefix));
 }
 
 /**
  * Manually resolve a single Babel plugin.
  */
-function resolvePlugin(plugin) {
+function resolvePlugin(plugin, prefix = 'babel-plugin-') {
   // Normalise plugin to an array.
   if (!Array.isArray(plugin)) {
     plugin = [plugin];
   }
   // Only resolve the plugin if it's a string reference.
   if (typeof plugin[0] === 'string') {
-    plugin[0] = require('babel-plugin-' + plugin[0]);
+    plugin[0] = require(prefix + plugin[0]);
     plugin[0] = plugin[0].__esModule ? plugin[0].default : plugin[0];
   }
   return plugin;
 }
 
 module.exports = resolvePlugins;
 module.exports.resolvePlugin = resolvePlugin;
+module.exports.resolvePluginAs = (prefix, plugin) =>
+  resolvePlugin(plugin, prefix);
+module.exports.resolvePluginsAs = (prefix, plugins) =>
+  resolvePlugins(plugins, prefix);