fix(args): fix args workaround for legacy api - don't overwrite config if second param is null or undefined - fixes #1006

Author: shakyShane

lib/args.js

@@ -41,11 +41,20 @@ module.exports = function (args) {
 
             } else {
 
-                config = args[1] || {};
+                if (args[1] === null || args[1] === undefined) {
 
-                if (!config.files) {
-                    config.files = args[0];
+                    config = args[0];
+
+                } else {
+
+                    // finally, second arg could be a plain object for config
+                    config = args[1] || {};
+
+                    if (!config.files) {
+                        config.files = args[0];
+                    }
                 }
+
             }
 
             break;