Prevent ember-cli watcher being assigned to node_modules

README.md

@@ -37,12 +37,13 @@ You can supply a tree if you want finer control:
 // ember-cli-build.js
 
 var Funnel = require('broccoli-funnel');
-
+var UnwatchedDir = require('broccoli-source').UnwatchedDir;
 // ...
 
 var app = new EmberApp(defaults, {
   nodeModulesToVendor: [
-    new Funnel('node_modules/some-package/dist/js', {
+    /* UnwatchedDir is optional, but it is rare to need a watcher assigned to a node_modules dependencies */
+    new Funnel(new UnwatchedDir('node_modules/some-package/dist/js'), {
       destDir: 'some-package',
       files: ['only-this-file.js']
     })

index.js

@@ -2,17 +2,26 @@
 'use strict';
 
 const mergeTrees = require('broccoli-merge-trees');
+const UnwatchedDir = require('broccoli-source').UnwatchedDir;
 
 module.exports = {
   name: 'ember-cli-node-modules-to-vendor',
 
   included(app) {
+    this._super.included.apply(this, arguments);
     this.app = app;
   },
 
   treeForVendor() {
     let app = this.app;
     let nodeModulesToVendor = app.options.nodeModulesToVendor || [];
-    return mergeTrees(nodeModulesToVendor);
+
+    return mergeTrees(nodeModulesToVendor.map(function(asset) {
+      if (typeof asset === 'string') {
+        return new UnwatchedDir(asset);
+      }
+
+      return asset;
+    }));
   }
 };

package.json

@@ -19,7 +19,8 @@
     "mocha": "cross-env DEBUG=ember-cli-addon-tests mocha"
   },
   "dependencies": {
-    "broccoli-merge-trees": "^2.0.0"
+    "broccoli-merge-trees": "^2.0.0",
+    "broccoli-source": "^1.1.0"
   },
   "devDependencies": {
     "broccoli-funnel": "^1.0.0",