Add more escape tests to process_shell_test.

tests/standalone/io/process_shell_test.dart

 // Copyright (c) 2013, 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.
 
 import "dart:io";
 
 void testRunShell() {
   test(args) {
     var options = new Options();
     var path = new Path(options.script);
@@ skipping 15 matching lines @@
           }
         });
   }
   test(["\""]);
   test(["a b"]);
   test(["'"]);
   test(["'\"\"'\"'\"'"]);
   test(["'\"\"'", "\"'\"'"]);
   test(["'\$HOME'"]);
   test(["'\$tmp'"]);
+  test(["arg'"]);
+  test(["arg\\'"]);

[kustermann, 2013/05/23 10:26:38]

If you want to make sure that escaping works correctly, you have to use more
than one argument.

[Anders Johnsen, 2013/05/23 15:22:57]

Done.

 }

[kustermann, 2013/05/23 10:26:38]

I've one more question regarding the functionality of this. Should I be able to
determine the home directory like this?
Process.runShell("echo", [r"$HOME"])

[Anders Johnsen, 2013/05/23 15:22:57]

Please see https://codereview.chromium.org/15883003/.

 
 void testShell() {
   test(args, expected) {
     var options = new Options();
     var path = new Path(options.script);
     path = path.directoryPath.join(new Path("process_echo_util.dart"));
     var command = "${options.executable} $path $args";
     Process.runShell(command, [])
         .then((result) {
           if (Platform.operatingSystem == "windows") {
@@ skipping 16 matching lines @@
   if (Platform.operatingSystem != 'windows') {
     test("arg1 arg2 > /dev/null", []);
   }
 }
 
 void main() {
   testRunShell();
   testShell();
 }