Make pub publish more user friendly:

utils/pub/directory_tree.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.
+
+/// A simple library for rendering a list of files as a directory tree.
+library directory_tree;
+
+import 'log.dart' as log;
+import 'path.dart' as path;
+
+/// Draws a directory tree for the given list of files. Given a list of files
+/// like:
+///
+///     TODO
+///     example/console_example.dart
+///     example/main.dart
+///     example/web copy/web_example.dart
+///     test/absolute_test.dart
+///     test/basename_test.dart
+///     test/dirname_test.dart
+///     test/extension_test.dart
+///     test/is_absolute_test.dart
+///     test/is_relative_test.dart
+///     test/join_test.dart
+///     test/normalize_test.dart
+///     test/relative_test.dart
+///     test/split_test.dart
+///     .gitignore
+///     README.md
+///     lib/path.dart
+///     pubspec.yaml
+///     test/all_test.dart
+///     test/path_posix_test.dart
+///     test/path_windows_test.dart
+///
+/// this will render:
+///
+///     |-- .gitignore
+///     |-- README.md
+///     |-- TODO
+///     |-- example
+///     |   |-- console_example.dart
+///     |   |-- main.dart
+///     |   '-- web copy
+///     |       '-- web_example.dart
+///     |-- lib
+///     |   '-- path.dart
+///     |-- pubspec.yaml
+///     '-- test
+///         |-- absolute_test.dart
+///         |-- all_test.dart
+///         |-- basename_test.dart
+///         |   (7 more...)
+///         |-- path_windows_test.dart
+///         |-- relative_test.dart
+///         '-- split_test.dart

[nweiz, 2012/12/12 21:21:21]

This is really nice-looking.

[Bob Nystrom, 2012/12/12 21:45:36]

Thanks!

+///
+String generateTree(List<String> files) {

[nweiz, 2012/12/12 21:21:21]

I feel like this should have the same signature as createTarGz (that is, taking
arbitrary paths and relativizing them within the function).

[Bob Nystrom, 2012/12/12 21:45:36]

So passing in the root directory? Otherwise, how does it know what to relativize
them against?

[nweiz, 2012/12/12 21:59:51]

Yes. createTarGz takes a list of files and a base path.

+  // Parse out the files into a tree of nested maps.
+  var root = {};
+  for (var file in files) {
+    var parts = path.split(file);
+    var directory = root;
+    for (var part in path.split(file)) {
+      directory = directory.putIfAbsent(part, () => {});
+    }
+  }
+
+  // Walk the map recursively and render to a string.
+  var buffer = new StringBuffer();
+  _draw(buffer, '', null, null, root);
+  return buffer.toString();
+}
+
+void _drawLine(StringBuffer buffer, String prefix, bool isLastChild,
+               String name) {
+  // Print lines.
+  buffer.add(prefix);
+  if (isLastChild == true) {

[nweiz, 2012/12/12 21:21:21]

if (isLastChild)

[Bob Nystrom, 2012/12/12 21:45:36]

It's nullable. But fixed.

[nweiz, 2012/12/12 21:59:51]

In practice, I don't think null is ever passed in here -- the "name != null"
check in _draw protects against that. Also, I don't think it should be nullable.

[Bob Nystrom, 2012/12/12 22:14:32]

The name != null check is new. That's how I avoid making it nullable now. :)

[nweiz, 2012/12/12 22:19:33]

I meant the one in _draw. _drawLine is never called with a null name.

+    buffer.add("'-- ");
+  } else if (isLastChild == false) {

[nweiz, 2012/12/12 21:21:21]

if (!isLastChild)

[Bob Nystrom, 2012/12/12 21:45:36]

Done.

+    buffer.add("|-- ");
+  }
+
+  // Print name.
+  buffer.add(name);
+  buffer.add('\n');
+}
+
+String _getPrefix(bool isLast) {

[nweiz, 2012/12/12 21:21:21]

Tri-state booleans are awful. Just pass in two separate parameters.

[Bob Nystrom, 2012/12/12 21:45:36]

Done.

+  if (isLast == true) {
+    return "    ";
+  } else if (isLast == false) {
+    return "|   ";
+  } else {
+    return "";
+  }
+}
+
+void _draw(StringBuffer buffer, String prefix, bool isLast,
+                 String name, Map children) {
+  // Don't draw a line for the root node.
+  if (name != null) _drawLine(buffer, prefix, isLast, name);
+
+  // Recurse to the children.
+  var childNames = new List.from(children.keys);
+  childNames.sort();
+
+  _drawChild(bool isLastChild, String child) {
+    var childPrefix = _getPrefix(isLast);
+    _draw(buffer, '$prefix$childPrefix', isLastChild, child, children[child]);
+  }
+
+  if (childNames.length <= 10) {
+    // Not too many, so show all the children.
+    for (var i = 0; i < childNames.length; i++) {
+      _drawChild(i == childNames.length - 1, childNames[i]);
+    }
+  } else {
+    // Show the first few.
+    _drawChild(false, childNames[0]);
+    _drawChild(false, childNames[1]);
+    _drawChild(false, childNames[2]);
+
+    // Elide the middle ones.
+    buffer.add(prefix);
+    buffer.add(_getPrefix(isLast));
+    buffer.add('|   (${childNames.length - 6} more...)\n');
+
+    // Show the last few.
+    _drawChild(false, childNames[childNames.length - 3]);
+    _drawChild(false, childNames[childNames.length - 2]);
+    _drawChild(true, childNames[childNames.length - 1]);
+  }
+}