Exception handling for files argument

fix #133, #205

lib/cli.js

@@ -94,5 +94,10 @@ function parseArgs(options) {//  \/\\*(?:(?!\\*\/)|.|\\n)*?\\*\/
 
   // what's left in argv
   args.files = process.argv.slice(parser.optind());
+  if (args.files.length < 1) {
+    console.log("One or more files ​​are required.");
+    info.help();
+    process.exit(1);
+  }
   return args;
 }

lib/util.js

@@ -11,7 +11,7 @@ var log = new Logger(Logger.WARNING);
 var path = require('path');
 
 exports.findCommonBase = function(files) {
-  if (!files || files.length === 1) return '';
+  if (!files || files.length < 2) return '';
   var lastSlash = files[0].lastIndexOf(path.sep);
   if (!lastSlash) return '';
   var first = files[0].substr(0, lastSlash + 1);

test/util_test.js

@@ -35,7 +35,7 @@ exports['util'] = {
     // Store value of current path separator (environment-specific)
     var sep = path.sep;
 
-    test.expect(6);
+    test.expect(7);
 
     // Explicitly set path for OSX/*nix environment path prefixing
     path.sep = '/';
@@ -71,6 +71,10 @@ exports['util'] = {
     ];
     test.equal(util.findCommonBase(files), '', 'should not find a prefix for files in the current directory');
 
+    files = [];
+    test.equal(util.findCommonBase(files), '', 'should not cause an error for no files');
+
+
     // Explicitly set path for Windows environment path prefixing
     path.sep = '\\';