Pub fix for Windows

utils/pub/io.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.
 
 /**
  * Helper functionality to make working with IO easier.
  */
 library io;
 
 import 'dart:io';
@@ skipping 481 matching lines @@
     args = flatten(["/c", executable, args]);
     executable = "cmd";
   }
 
   final options = new ProcessOptions();
   if (workingDir != null) {
     options.workingDirectory = _getDirectory(workingDir).path;
   }
   options.environment = environment;
 
-  final process = Process.start(executable, args, options);
-
-  final outStream = new StringInputStream(process.stdout);
-  final processStdout = <String>[];
-
-  final errStream = new StringInputStream(process.stderr);
-  final processStderr = <String>[];
-
-  final completer = new Completer<PubProcessResult>();
-
-  checkComplete() {
-    // Wait until the process is done and its output streams are closed.
-    if (!pipeStdout && !outStream.closed) return;
-    if (!pipeStderr && !errStream.closed) return;
-    if (exitCode == null) return;
-
-    completer.complete(new PubProcessResult(
-        processStdout, processStderr, exitCode));
-  }
-
-  if (pipeStdout) {
-    process.stdout.pipe(stdout, close: false);
-  } else {
-    outStream.onLine   = () => processStdout.add(outStream.readLine());
-    outStream.onClosed = checkComplete;
-    outStream.onError  = (error) => completer.completeException(error);
-  }
-
-  if (pipeStderr) {
-    process.stderr.pipe(stderr, close: false);
-  } else {
-    errStream.onLine   = () => processStderr.add(errStream.readLine());
-    errStream.onClosed = checkComplete;
-    errStream.onError  = (error) => completer.completeException(error);
-  }
-
-  process.onExit = (actualExitCode) {
-    exitCode = actualExitCode;
-    checkComplete();
-  };
-
-  process.onError = (error) => completer.completeException(error);
-
-  return completer.future;
+  var future = Process.run(executable, args, options);
+  return future.transform((result) {
+    return new PubProcessResult(result.stdout, result.stderr, result.exitCode);
+  });

[Bob Nystrom, 2012/10/16 14:07:29]

Well this is a distinct improvement. :)

This code in pub is older than Process.run, and this is much better.

At the same time, I would like to know more about where the issue was in the
original code. Since that API is still available, other users could likely
misuse it the same way I was. Any idea what was wrong with the old code?

[Anders Johnsen, 2012/10/16 14:29:57]

There is nothing wrong with the old code, other then the same issues that lead
to us introducing Process.run: it's very easy to do wrong. You have to wait for
several events to occur, and make sure all the underlying pipes are closed. I
saw this when we looked for the issue, and thought that the error might be
originated here. It turned up it was't, but I though we should keep the change
in anyway :)

[nweiz, 2012/10/16 17:20:15]

This doesn't support pipeStdout/pipeStderr. Either those arguments should be
removed or we should support them.

[Anders Johnsen, 2012/10/17 07:05:25]

Ahh, good point. Bob, is the piping needed in Pub? Otherwise, feel free to
revert this part of the patch.

[Bob Nystrom, 2012/10/17 16:25:52]

It doesn't look like we're using that right now, so I think we're OK. We'll be
adding "--verbose" support to pub relatively soon and we can revisit this then.

 }
 
 /**
  * Wraps [input] to provide a timeout. If [input] completes before
  * [milliseconds] have passed, then the return value completes in the same way.
  * However, if [milliseconds] pass before [input] has completed, it completes
  * with a [TimeoutException] with [message].
  *
  * Note that timing out will not cancel the asynchronous operation behind
  * [input].
@@ skipping 229 matching lines @@
   return new Directory(entry);
 }
 
 /**
  * Gets a [Uri] for [uri], which can either already be one, or be a [String].
  */
 Uri _getUri(uri) {
   if (uri is Uri) return uri;
   return new Uri.fromString(uri);
 }