Add a function to pub for finding the canonical path of a file.

Add a function to pub for finding the canonical path of a file.

This allows listDir to work properly with recursive symlinks on Windows.

BUG=7505
R=rnystrom@google.com

Committed: https://code.google.com/p/dart/source/detail?r=22477

[Bob Nystrom, 2013-05-07 17:36:14]

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
File sdk/lib/_internal/pub/lib/src/io.dart (right):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
sdk/lib/_internal/pub/lib/src/io.dart:52: var newPath = components.removeAt(0);
A comment explaining how this works would help. Something like:

Rebuild the path one component at a time, resolving through each directory that
happens to be a symlink.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
sdk/lib/_internal/pub/lib/src/io.dart:59: /// Returns the transitive target of
[link]. If [link] is recursive, this
"transitive target" doesn't mean anything to me, so this comment isn't helpful.
Maybe "resolveLink"?

"recursive" could also be defined more precisely. Does it mean a symlink that
points to one of its parent directories?

Better doc and maybe a few examples showing how different paths will be
processed.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/pub....
File sdk/lib/_internal/pub/pub.status (right):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/pub....
sdk/lib/_internal/pub/pub.status:16: [ $system == windows ]
Delete this too.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/test...
File sdk/lib/_internal/pub/test/install/path/shared_dependency_symlink_test.dart
(left):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/test...
sdk/lib/_internal/pub/test/install/path/shared_dependency_symlink_test.dart:15:
if (Platform.operatingSystem == "windows") return;
Nice!

[nweiz, 2013-05-07 20:40:15]

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
File sdk/lib/_internal/pub/lib/src/io.dart (right):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
sdk/lib/_internal/pub/lib/src/io.dart:52: var newPath = components.removeAt(0);
On 2013/05/07 17:36:14, Bob Nystrom wrote:
> A comment explaining how this works would help. Something like:
> 
> Rebuild the path one component at a time, resolving through each directory
that
> happens to be a symlink.

Done.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
sdk/lib/_internal/pub/lib/src/io.dart:59: /// Returns the transitive target of
[link]. If [link] is recursive, this
On 2013/05/07 17:36:14, Bob Nystrom wrote:
> "transitive target" doesn't mean anything to me, so this comment isn't
helpful.
> Maybe "resolveLink"?

I think "transitive target" is pretty clear; symlinks have a target which may be
a symlink, and transitively following those targets gives you the transitive
target. I'll change the name if you want, but I think this is clearest.

> "recursive" could also be defined more precisely. Does it mean a symlink that
> points to one of its parent directories?

Done.

> Better doc and maybe a few examples showing how different paths will be
> processed.

Done.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/pub....
File sdk/lib/_internal/pub/pub.status (right):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/pub....
sdk/lib/_internal/pub/pub.status:16: [ $system == windows ]
On 2013/05/07 17:36:14, Bob Nystrom wrote:
> Delete this too.

Done.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/test...
File sdk/lib/_internal/pub/test/install/path/shared_dependency_symlink_test.dart
(left):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/test...
sdk/lib/_internal/pub/test/install/path/shared_dependency_symlink_test.dart:15:
if (Platform.operatingSystem == "windows") return;
On 2013/05/07 17:36:14, Bob Nystrom wrote:
> Nice!

Let's see if it breaks the bots before we celebrate too much :p.

[Bob Nystrom, 2013-05-07 20:43:07]

I'd still prefer maybe "resolvePath" but otherwise LGTM.

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
File sdk/lib/_internal/pub/lib/src/io.dart (right):

https://codereview.chromium.org/14924006/diff/3001/sdk/lib/_internal/pub/lib/...
sdk/lib/_internal/pub/lib/src/io.dart:59: /// Returns the transitive target of
[link]. If [link] is recursive, this
On 2013/05/07 20:40:15, nweiz wrote:
> On 2013/05/07 17:36:14, Bob Nystrom wrote:
> > "transitive target" doesn't mean anything to me, so this comment isn't
> helpful.
> > Maybe "resolveLink"?
> 
> I think "transitive target" is pretty clear; symlinks have a target which may
be
> a symlink, and transitively following those targets gives you the transitive
> target.

Maybe, but I think "resolved" is the more common term for a path that takes
symlinks into account. Also, this method is used for paths to things that are
not symlinks, so "target" isn't always meaningful.

> I'll change the name if you want, but I think this is clearest.
> 
> > "recursive" could also be defined more precisely. Does it mean a symlink
that
> > points to one of its parent directories?
> 
> Done.
> 
> > Better doc and maybe a few examples showing how different paths will be
> > processed.
> 
> Done.

[nweiz, 2013-05-07 20:55:47]

Committed patchset #3 manually as r22477 (presubmit successful).