Make pathos run in the browser.

pkg/pathos/test/pathos_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 pathos_posix_test;
 
-import 'dart:io' as io;
-
 import 'package:unittest/unittest.dart';
 import 'package:pathos/path.dart' as path;
 
 main() {
   var builder = new path.Builder(style: path.Style.posix, root: '/root/path');
 
   if (new path.Builder().style == path.Style.posix) {
     group('absolute', () {
       expect(path.absolute('a/b.txt'), path.join(path.current, 'a/b.txt'));
       expect(path.absolute('/a/b.txt'), '/a/b.txt');
@@ skipping 274 matching lines @@
       test('given relative path', () {
         // The path is considered relative to the root, so it basically just
         // normalizes.
         expect(builder.relative(''), '.');
         expect(builder.relative('.'), '.');
         expect(builder.relative('a'), 'a');
         expect(builder.relative('a/b.txt'), 'a/b.txt');
         expect(builder.relative('../a/b.txt'), '../a/b.txt');
         expect(builder.relative('a/./b/../c.txt'), 'a/c.txt');
       });
+
+      // Regression
+      test('from root-only path', () {
+        expect(builder.relative('/', from: '/'), '.');
+        expect(builder.relative('/root/path', from: '/'), 'root/path');
+      });
     });
 
     group('from relative root', () {
       var r = new path.Builder(style: path.Style.posix, root: 'foo/bar');
 
       test('given absolute path', () {
         expect(r.relative('/'), equals('/'));
         expect(r.relative('/a/b'), equals('/a/b'));
       });
 
@@ skipping 24 matching lines @@
     });
 
     test('with a root parameter and a relative root', () {
       var r = new path.Builder(style: path.Style.posix, root: 'relative/root');
       expect(r.relative('/foo/bar/baz', from: '/foo/bar'), equals('baz'));
       expect(() => r.relative('..', from: '/foo/bar'), throwsArgumentError);
       expect(r.relative('/foo/bar/baz', from: 'foo/bar'),
           equals('/foo/bar/baz'));
       expect(r.relative('..', from: 'foo/bar'), equals('../../..'));
     });
+
+    test('from a . root', () {
+      var r = new path.Builder(style: path.Style.posix, root: '.');
+      expect(r.relative('/foo/bar/baz'), equals('/foo/bar/baz'));
+      expect(r.relative('foo/bar/baz'), equals('foo/bar/baz'));
+    });
   });
 
   group('resolve', () {
     test('allows up to seven parts', () {
       expect(builder.resolve('a'), '/root/path/a');
       expect(builder.resolve('a', 'b'), '/root/path/a/b');
       expect(builder.resolve('a', 'b', 'c'), '/root/path/a/b/c');
       expect(builder.resolve('a', 'b', 'c', 'd'), '/root/path/a/b/c/d');
       expect(builder.resolve('a', 'b', 'c', 'd', 'e'), '/root/path/a/b/c/d/e');
       expect(builder.resolve('a', 'b', 'c', 'd', 'e', 'f'),
@@ skipping 26 matching lines @@
     expect(builder.withoutExtension('a/.'), 'a/.');
     expect(builder.withoutExtension('a/.b'), 'a/.b');
     expect(builder.withoutExtension('a.b/c'), 'a.b/c');
     expect(builder.withoutExtension(r'a.b\c'), r'a');
     expect(builder.withoutExtension(r'a/b\c'), r'a/b\c');
     expect(builder.withoutExtension(r'a/b\c.d'), r'a/b\c');
     expect(builder.withoutExtension('a/b.c/'), 'a/b/');
     expect(builder.withoutExtension('a/b.c//'), 'a/b//');
   });
 }