Support relative paths in path dependencies.

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:async';
 import 'dart:io';
 import 'dart:isolate';
@@ skipping 246 matching lines @@
 
       // Wait a bit and try again.
       log.fine("Operation failed, retrying (attempt $attempts).");
       return sleep(500).then(makeAttempt);
     });
   }
 
   return makeAttempt(null);
 }
 
-/// Creates a new symlink that creates an alias from [from] to [to]. Returns a
-/// [Future] which completes to the symlink file (i.e. [to]).
+/// Creates a new symlink at path [symlink] that points to [target]. Returns a
+/// [Future] which completes to the symlink file.

[nweiz, 2013/02/15 23:09:24]

"to the path to the symlink file"; same below

[Bob Nystrom, 2013/02/16 00:09:57]

Done.

+///
+/// If [relative] is true, creates a symlink with a relative path from the
+/// symlink to the target. Otherwise, uses the [target] path unmodified.
 ///
 /// Note that on Windows, only directories may be symlinked to.
-Future<String> createSymlink(String from, String to) {
-  log.fine("Creating symlink ($to is a symlink to $from)");
+Future<String> createSymlink(String symlink, String target,

[nweiz, 2013/02/15 23:09:24]

I don't like the parameter reordering here. It should have the same order as "ln
-s".

[Bob Nystrom, 2013/02/16 00:09:57]

It's always going to be wrong for one OS. I found both orderings confusing but I
went this way because I think it's more consistent with other create___ methods
here, like createTextFile(path, content).

[nweiz, 2013/02/16 01:02:14]

The way it is now is wrong for all but one OS, and the OS it's right for is the
one that uses symlinks the least.
I'd rather be consistent with the most-commonly-used symlink utility. Don't
think of creating a symlink as creating a file as content; think of it as an
analogue to copying a file from one place to another. The argument order for "ln
-s" is the same as it would be if you were using "cp" instead.

[Bob Nystrom, 2013/02/16 01:19:03]

Done.

+    {bool relative: false}) {
+  if (relative) {
+    target = path.normalize(path.relative(target, from: path.dirname(symlink)));
+  }
+
+  log.fine("Creating $symlink pointing to $target");
 
   var command = 'ln';
-  var args = ['-s', from, to];
+  var args = ['-s', target, symlink];
 
   if (Platform.operatingSystem == 'windows') {
     // Call mklink on Windows to create an NTFS junction point. Only works on
     // Vista or later. (Junction points are available earlier, but the "mklink"
     // command is not.) I'm using a junction point (/j) here instead of a soft
     // link (/d) because the latter requires some privilege shenanigans that
     // I'm not sure how to specify from the command line.
     command = 'mklink';
-    args = ['/j', to, from];
+    args = ['/j', symlink, target];
   }
 
   // TODO(rnystrom): Check exit code and output?
-  return runProcess(command, args).then((result) => to);
+  return runProcess(command, args).then((result) => symlink);
 }
 
-/// Creates a new symlink that creates an alias from the `lib` directory of
-/// package [from] to [to]. Returns a [Future] which completes to the symlink
-/// file (i.e. [to]). If [from] does not have a `lib` directory, this shows a
+/// Creates a new symlink that creates an alias at [symlink] that points to the
+/// `lib` directory of package [target]. Returns a [Future] which completes to
+/// the symlink file. If [target] does not have a `lib` directory, this shows a
 /// warning if appropriate and then does nothing.
-Future<String> createPackageSymlink(String name, String from, String to,
-    {bool isSelfLink: false}) {
+///
+/// If [relative] is true, creates a symlink with a relative path from the
+/// symlink to the target. Otherwise, uses the [target] path unmodified.
+Future<String> createPackageSymlink(String name, String symlink, String target,
+    {bool isSelfLink: false, bool relative: false}) {
   return defer(() {
     // See if the package has a "lib" directory.
-    from = path.join(from, 'lib');
+    target = path.join(target, 'lib');
     log.fine("Creating ${isSelfLink ? "self" : ""}link for package '$name'.");
-    if (dirExists(from)) return createSymlink(from, to);
+    if (dirExists(target)) {
+      return createSymlink(symlink, target, relative: relative);
+    }
 
     // It's OK for the self link (i.e. the root package) to not have a lib
     // directory since it may just be a leaf application that only has
     // code in bin or web.
     if (!isSelfLink) {
       log.warning('Warning: Package "$name" does not have a "lib" directory so '
                   'you will not be able to import any libraries from it.');
     }
 
-    return to;
+    return symlink;
   });
 }
 
 /// Resolves [target] relative to the location of pub.dart.
 String relativeToPub(String target) {
   var scriptPath = new File(new Options().script).fullPathSync();
 
   // Walk up until we hit the "util(s)" directory. This lets us figure out where
   // we are if this function is called from pub.dart, or one of the tests,
   // which also live under "utils", or from the SDK where pub is in "util".
@@ skipping 538 matching lines @@
   const PubProcessResult(this.stdout, this.stderr, this.exitCode);
 
   bool get success => exitCode == 0;
 }
 
 /// 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 Uri.parse(uri);
 }