Make pub generate .packages file.

lib/src/package_locations.dart

+// Copyright (c) 2015, 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.
+
+/// Keeps track of used package locations, and can create a package dictionary.

[nweiz, 2015/06/10 22:33:59]

"used package locations" -> "the locations of packages installed in the
entrypoint"

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Reworded.

+///
+/// A package dictionary is currently a `.packages` file.

[nweiz, 2015/06/10 22:33:58]

What do you mean by "currently"?

[Lasse Reichstein Nielsen, 2015/06/11 11:21:01]

Too specualtive, yes. Removed.

+library pub.package_locations;
+// TODO(lrn): Also move packages/ directory management to this library.

[nweiz, 2015/06/10 22:33:58]

Nit: Move this above the library tag.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Done.

+
+import 'package:package_config/packages_file.dart' as pkgfile;

[nweiz, 2015/06/10 22:33:58]

We tend to use full words for identifiers except in a few special cases. I'd
call this prefix "packages_file".

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Done.

+
+import 'package_graph.dart';
+import 'io.dart';
+import 'log.dart' as log;
+import 'utils.dart' show ordered;
+
+/// Creates a `.packages` file with the location of the packges in `graph`.

[nweiz, 2015/06/10 22:33:58]

"location" -> "locations", "packges" -> "packages", "`graph`" -> "[graph]"

[Lasse Reichstein Nielsen, 2015/06/11 11:21:01]

Done.

+///
+/// The file is written next to the entry-point of [graph],

[nweiz, 2015/06/10 22:33:58]

"next to" -> "in the root directory of", "entry-point" -> "entrypoint"

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Done.

+/// unless [file] is provided, in which case that file is written to instead.
+///
+/// If the file already exists, it is deleted before the new content is written.
+void writePackagesMap(PackageGraph graph, {String file}) {

[nweiz, 2015/06/10 22:33:58]

[file] isn't used in this patch and I don't see any reason for its use, so it
should be removed.

Nit: we call it a "packages file" elsewhere, so these method names should
reflect that.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:01]

Done.

+  if (file == null) file = graph.entrypoint.root.path(".packages");
+  print("WRITE!: $file");

[nweiz, 2015/06/10 22:33:58]

Remove this as well as debugging prints below.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Done.

+  deleteEntry(file);
+  var content = _createPackagesMap(graph, file);
+  try {
+    print("WRITE FILE");
+    writeTextFile(file, content);
+    print("WROTE FILE");
+  } catch (error, stackTrace) {

[nweiz, 2015/06/10 22:33:58]

This should be a fatal error.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

How do you make it fatal? Not catching it?

[nweiz, 2015/06/12 23:48:08]

Yeah, that's all that I mean.

[Lasse Reichstein Nielsen, 2015/06/23 14:54:33]

Done.

[Lasse Reichstein Nielsen, 2015/06/23 14:54:33]

Done.

+    print("DNWRITE: $error");
+    log.error(error, stackTrace);
+  }
+}
+
+/// Template for header text put into `.packages` file.
+///
+/// Contains the literal string `$now` which should be replaced by a timestamp.
+const _headerText = r"""
+Generate by pub on $now.
+This file contains a map from Dart package names to Dart package locations.
+Dart tools, including Dart VM and Dart analyzer, rely on the content.

[nweiz, 2015/06/10 22:33:58]

"Dart VM" -> "the Dart VM".

[Lasse Reichstein Nielsen, 2015/06/11 11:21:01]

Done.

+AUTO GENERATED - DO NOT EDIT
+""";
+
+/// Creates `.packages` file content from the packages in a package graph.

[nweiz, 2015/06/10 22:33:58]

"Creates" -> "Returns the contents of the"

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Done.

+String _createPackagesMap(PackageGraph packageGraph, File packagesFile) {

[nweiz, 2015/06/10 22:33:58]

"packagesFile" is a string.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:01]

Acknowledged.

+  var header = _headerText.replaceFirst(r"$now", new DateTime.now().toString());
+
+  Uri fileUri = new Uri.file(packagesFile);

[nweiz, 2015/06/10 22:33:58]

Nit: don't type-annotate local variables, and move this down closer to where
it's actually used.

Use [p.toUri] here for consistency with the rest of the code.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:01]

Done.

+
+  var packages = packageGraph.packages;
+  var uriMap = {};
+  for (var packageName in ordered(packages.keys)) {
+    var location = packages[packageName].path("lib/");

[nweiz, 2015/06/10 22:33:59]

Don't include a trailing "/" here.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Done. The result will have the trailing / anyway, yey!

+    uriMap[packageName] = new Uri.directory(location);

[nweiz, 2015/06/10 22:33:59]

I don't think [Uri.directory] exists. Regardless, use [p.toUri] instead.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

It exists/will exist in v1.11, but using path.toUri anyway.

+  }
+
+  var text = new StringBuffer();
+  pkgfile.write(text, uriMap, baseUri: fileUri, comment: header);

[nweiz, 2015/06/10 22:33:58]

We shouldn't pass [baseUri] here. Most types of dependencies will require paths
to the pub cache, and making those paths relative will cause breakage if the
package spec is moved around.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Sounds fair. Omitting baseUri should avoid any relativization.

+  return text.toString();
+}