Test empty strings arguments to path.join().

pkg/path/test/posix_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library path.test.posix_test;
 
 import 'package:unittest/unittest.dart';
 import 'package:path/path.dart' as path;
 
 main() {
@@ skipping 135 matching lines @@
       expect(builder.join('a', '/b', '/c', 'd'), '/c/d');
       expect(builder.join('a', r'c:\b', 'c', 'd'), r'a/c:\b/c/d');
       expect(builder.join('a', r'\\b', 'c', 'd'), r'a/\\b/c/d');
     });
 
     test('ignores trailing nulls', () {
       expect(builder.join('a', null), equals('a'));
       expect(builder.join('a', 'b', 'c', null, null), equals('a/b/c'));
     });
 
+    test('ignores empty strings', () {
+      expect(builder.join(''), '');
+      expect(builder.join('', ''), '');
+      expect(builder.join('', 'a'), 'a');
+      expect(builder.join('a', '', 'b', '', '', '', 'c'), 'a/b/c');
+      expect(builder.join('a', 'b', ''), 'a/b');
+    });
+
     test('disallows intermediate nulls', () {
       expect(() => builder.join('a', null, 'b'), throwsArgumentError);
       expect(() => builder.join(null, 'a'), throwsArgumentError);
     });
   });
 
   group('joinAll', () {
     test('allows more than eight parts', () {
       expect(builder.joinAll(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i']),
           'a/b/c/d/e/f/g/h/i');
@@ skipping 249 matching lines @@
 
   test('toUri', () {
     expect(builder.toUri('/path/to/foo'), Uri.parse('file:///path/to/foo'));
     expect(builder.toUri('/path/to/foo/'), Uri.parse('file:///path/to/foo/'));
     expect(builder.toUri('/'), Uri.parse('file:///'));
     expect(builder.toUri('foo/bar'), Uri.parse('foo/bar'));
     expect(builder.toUri('/path/to/foo#bar'),
         Uri.parse('file:///path/to/foo%23bar'));
   });
 }