Merge pull request #839 from am11/master

Code: Skips path.resolve when outFile is not set

lib/index.js

@@ -55,7 +55,7 @@ function getSourceMap(options) {
     sourceMap = options.outFile + '.map';
   }
 
-  return sourceMap ? path.resolve(sourceMap) : null;
+  return sourceMap && typeof sourceMap === 'string' ? path.resolve(sourceMap) : null;
 }
 
 /**