Use safeWalkSync in case folders are missing

Author: andyhot

lib/index.js

@@ -45,24 +45,23 @@ var Engine = CoreObject.extend({
       });
   },
 
+  _safeWalkSync: function(dir) {
+    var projectDir = this.projectRoot + '/' + dir;
+    return fse.existsSync(projectDir) ? walkSync(projectDir) : [];
+  },
+
   _filesInDir: function(dir) {
-    return walkSync(this.projectRoot + '/' + dir)
-      .map(function(relativePath) {
-        // add the dir back as a prefix
-        return dir + '/' + relativePath;
-      })
-      .filter(function(relativePath) {
-        // remove entries for directories
-        return relativePath.slice(-1) !== '/';
-      });
+    return this._safeWalkSync(dir)
+      // add the dir back as a prefix
+      .map( relativePath => dir + '/' + relativePath )
+      // remove entries for directories
+      .filter( relativePath => relativePath.slice(-1) !== '/');
   },
 
   _queueRemoveEmptyDirs: function(dir) {
-    var projectRoot = this.projectRoot;
-
     this._promise = this._promise
-      .then(function() {
-        var contents = walkSync(projectRoot + '/' + dir);
+      .then(() => {
+        var contents = this._safeWalkSync(dir);
         var files = contents
               .filter(function(entry) {
                 return entry.slice(-1) !== '/' && entry.slice(-8) !== '.gitkeep';
@@ -74,7 +73,7 @@ var Engine = CoreObject.extend({
 
         // there are no files left
         if (files.length === 0) {
-          fse.removeSync(projectRoot + '/' + dir);
+          fse.removeSync(this.projectRoot + '/' + dir);
         }
 
         // there are files, so we need to only delete empty dirs
@@ -86,7 +85,7 @@ var Engine = CoreObject.extend({
                 });
 
           if (!hasFiles) {
-            fse.removeSync(projectRoot + '/' + dir + '/' + directory);
+            fse.removeSync(this.projectRoot + '/' + dir + '/' + directory);
           }
         }
       });