Support directories other than "web" in pub build.

sdk/lib/_internal/pub/lib/src/barback/build_environment.dart

Index: sdk/lib/_internal/pub/lib/src/barback/build_environment.dart
diff --git a/sdk/lib/_internal/pub/lib/src/barback/build_environment.dart b/sdk/lib/_internal/pub/lib/src/barback/build_environment.dart
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+// Copyright (c) 2014, 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.
+
+library pub.barback.build_environment;
+
+import 'dart:async';
+
+import 'package:barback/barback.dart';
+import 'package:path/path.dart' as path;
+import 'package:stack_trace/stack_trace.dart';
+import 'package:watcher/watcher.dart';
+
+import '../entrypoint.dart';
+import '../io.dart';
+import '../log.dart' as log;
+import '../package.dart';
+import '../package_graph.dart';
+import '../utils.dart';
+import 'dart_forwarding_transformer.dart';
+import 'dart2js_transformer.dart';
+import 'load_all_transformers.dart';
+import 'pub_package_provider.dart';
+import 'server.dart';
+
+/// The entire "visible" state of the assets of a package and all of its
+/// dependencies, taking into account the user's configuration when running pub.
+///
+/// Where [PackageGraph] just describes the entrypoint's dependencies as
+/// specified by pubspecs, this includes "transient" information like the mode
+/// that the user is running pub in, or which directories they want to build.
+class BuildEnvironment {
+  /// Creates a new build environment for working with the assets used by
+  /// [entrypoint] and its dependencies.
+  ///
+  /// Spawns an HTTP server on [hostname] and [port]. Loads all used
+  /// transformers using [mode] (including dart2js if [useDart2JS] is true).
+  ///
+  /// Includes [buildDirectories] in the root package, as well as "lib" and
+  /// "asset".
+  ///
+  /// If [watcherType] is not [WatcherType.NONE], watches source assets for
+  /// modification.
+  ///
+  /// Returns a [Future] that completes to the environment once the inputs,
+  /// transformers, and server are loaded and ready.
+  static Future<BuildEnvironment> create(Entrypoint entrypoint,
+      String hostname, int port, BarbackMode mode, WatcherType watcherType,
+      Set<String> buildDirectories,
+      {bool useDart2JS: true}) {
+    return entrypoint.loadPackageGraph().then((graph) {
+      var barback = new Barback(new PubPackageProvider(graph));
+      barback.log.listen(_log);
+
+      return BarbackServer.bind(hostname, port, barback,
+          graph.entrypoint.root.name).then((server) {
+        var environment = new BuildEnvironment._(graph, server, mode,
+            watcherType, buildDirectories);
+
+        // If the entrypoint package manually configures the dart2js
+        // transformer, don't include it in the built-in transformer list.
+        //
+        // TODO(nweiz): if/when we support more built-in transformers, make
+        // this more general.
+        var containsDart2JS = graph.entrypoint.root.pubspec.transformers
+            .any((transformers) => transformers
+            .any((id) => id.package == '\$dart2js'));
+
+        if (!containsDart2JS && useDart2JS) {
+          environment._builtInTransformers.addAll([
+            new Dart2JSTransformer(environment, mode),
+            new DartForwardingTransformer(mode)
+          ]);
+        }
+
+        return environment._load(barback).then((_) => environment);
+      });
+    });
+  }
+
+  /// The server serving this environment's assets.
+  final BarbackServer server;
+
+  /// The [Barback] instance used to process assets in this environment.
+  Barback get barback => server.barback;
+
+  /// The root package being built.
+  Package get rootPackage => graph.entrypoint.root;
+
+  /// The underlying [PackageGraph] being built.
+  final PackageGraph graph;
+
+  /// The mode to run the transformers in.
+  final BarbackMode mode;
+
+  /// The [Transformer]s that should be appended by default to the root
+  /// package's transformer cascade. Will be empty if there are none.
+  final _builtInTransformers = <Transformer>[];
+
+  /// How source files should be watched.
+  final WatcherType _watcherType;
+
+  /// The set of top-level directories in the entrypoint package that should be
+  /// built.
+  final Set<String> _buildDirectories;
+
+  BuildEnvironment._(this.graph, this.server, this.mode, this._watcherType,
+      this._buildDirectories);
+
+  /// Gets the built-in [Transformer]s that should be added to [package].
+  ///
+  /// Returns `null` if there are none.
+  Iterable<Transformer> getBuiltInTransformers(Package package) {
+    // Built-in transformers only apply to the root package.
+    if (package.name != rootPackage.name) return null;
+
+    // The built-in transformers are for dart2js and forwarding assets around
+    // dart2js.
+    if (_builtInTransformers.isEmpty) return null;
+
+    return _builtInTransformers;
+  }
+
+  /// Creates a [BarbackServer] for this environment.
+  ///
+  /// This transforms and serves all library and asset files in all packages in
+  /// the environment's package graph. It loads any transformer plugins defined
+  /// in packages in [graph] and re-runs them as necessary when any input files
+  /// change.
+  ///
+  /// Returns a [Future] that completes once all inputs and transformers are
+  /// loaded.
+  Future _load(Barback barback) {
+    return _provideSources(barback).then((_) {
+      var completer = new Completer();
+
+      // If any errors get emitted either by barback or by the server,
+      // including non-programmatic barback errors, they should take down the
+      // whole program.
+      var subscriptions = [
+        server.barback.errors.listen((error) {
+          if (error is TransformerException) error = error.error;
+          if (!completer.isCompleted) {
+            completer.completeError(error, new Chain.current());
+          }
+        }),
+        server.barback.results.listen((_) {}, onError: (error, stackTrace) {
+          if (completer.isCompleted) return;
+          completer.completeError(error, stackTrace);
+        }),
+        server.results.listen((_) {}, onError: (error, stackTrace) {
+          if (completer.isCompleted) return;
+          completer.completeError(error, stackTrace);
+        })
+      ];
+
+      loadAllTransformers(this).then((_) {
+        if (!completer.isCompleted) completer.complete();
+      }).catchError((error, stackTrace) {
+        if (!completer.isCompleted) {
+          completer.completeError(error, stackTrace);
+        }
+      });
+
+      return completer.future.whenComplete(() {
+        for (var subscription in subscriptions) {
+          subscription.cancel();
+        }
+      });
+    });
+  }
+
+  /// Provides all of the source assets in the environment to barback.
+  ///
+  /// If [watcherType] is not [WatcherType.NONE], enables watching on them.
+  Future _provideSources(Barback barback) {
+    if (_watcherType != WatcherType.NONE) {
+      return _watchSources(barback);
+    }
+
+    return syncFuture(() {
+      _loadSources(barback);
+    });
+  }
+
+  /// Provides all of the source assets in the environment to barback.
+  void _loadSources(Barback barback) {
+    for (var package in graph.packages.values) {
+      barback.updateSources(_listAssets(graph.entrypoint, package));
+    }
+  }
+
+  /// Adds all of the source assets in this environment to barback and then
+  /// watches the public directories for changes.
+  ///
+  /// Returns a Future that completes when the sources are loaded and the
+  /// watchers are active.
+  Future _watchSources(Barback barback) {
+    return Future.wait(graph.packages.values.map((package) {
+      // If this package comes from a cached source, its contents won't change
+      // so we don't need to monitor it. `packageId` will be null for the
+      // application package, since that's not locked.
+      var packageId = graph.lockFile.packages[package.name];
+      if (packageId != null &&
+          graph.entrypoint.cache.sources[packageId.source].shouldCache) {
+        barback.updateSources(_listAssets(graph.entrypoint, package));
+        return new Future.value();
+      }
+
+      // Watch the visible package directories for changes.
+      return Future.wait(_getPublicDirectories(graph.entrypoint, package)
+          .map((name) {
+        var subdirectory = path.join(package.dir, name);
+        if (!dirExists(subdirectory)) return new Future.value();
+
+        // TODO(nweiz): close these watchers when [barback] is closed.
+        var watcher = _watcherType.create(subdirectory);
+        watcher.events.listen((event) {
+          // Don't watch files symlinked into these directories.
+          // TODO(rnystrom): If pub gets rid of symlinks, remove this.
+          var parts = path.split(event.path);
+          if (parts.contains("packages") || parts.contains("assets")) return;
+
+          // Skip ".js" files that were (most likely) compiled from nearby
+          // ".dart" files. These are created by the Editor's "Run as
+          // JavaScript" command and are written directly into the package's
+          // directory. When pub's dart2js transformer then tries to create the
+          // same file name, we get a build error. To avoid that, just don't
+          // consider that file to be a source.
+          // TODO(rnystrom): Remove this when the Editor no longer generates
+          // .js files. See #15859.
+          if (event.path.endsWith(".dart.js")) return;
+
+          var id = new AssetId(package.name,
+              path.relative(event.path, from: package.dir));
+          if (event.type == ChangeType.REMOVE) {
+            barback.removeSources([id]);
+          } else {
+            barback.updateSources([id]);
+          }
+        });
+        return watcher.ready;
+      })).then((_) {
+        barback.updateSources(_listAssets(graph.entrypoint, package));
+      });
+    }));
+  }
+
+  /// Lists all of the visible files in [package].
+  ///
+  /// This is the recursive contents of the "asset" and "lib" directories (if
+  /// present). If [package] is the entrypoint package, it also includes the
+  /// contents of "web".
+  List<AssetId> _listAssets(Entrypoint entrypoint, Package package) {
+    var files = <AssetId>[];
+
+    for (var dirPath in _getPublicDirectories(entrypoint, package)) {
+      var dir = path.join(package.dir, dirPath);
+      if (!dirExists(dir)) continue;
+      for (var entry in listDir(dir, recursive: true)) {
+        // Ignore "packages" symlinks if there.
+        if (path.split(entry).contains("packages")) continue;
+
+        // Skip directories.
+        if (!fileExists(entry)) continue;
+
+        // Skip ".js" files that were (most likely) compiled from nearby ".dart"
+        // files. These are created by the Editor's "Run as JavaScript" command
+        // and are written directly into the package's directory. When pub's
+        // dart2js transformer then tries to create the same file name, we get
+        // a build error. To avoid that, just don't consider that file to be a
+        // source.
+        // TODO(rnystrom): Remove this when the Editor no longer generates .js
+        // files. See #15859.
+        if (entry.endsWith(".dart.js")) continue;
+
+        var id = new AssetId(package.name,
+            path.relative(entry, from: package.dir));
+        files.add(id);
+      }
+    }
+
+    return files;
+  }
+
+  /// Gets the names of the top-level directories in [package] whose contents
+  /// should be provided as source assets.
+  Iterable<String> _getPublicDirectories(Entrypoint entrypoint,
+      Package package) {
+    var directories = ["asset", "lib"];
+
+    if (package.name == entrypoint.root.name) {
+      directories.addAll(_buildDirectories);
+    }
+
+    return directories;
+  }
+}
+
+/// Log [entry] using Pub's logging infrastructure.
+///
+/// Since both [LogEntry] objects and the message itself often redundantly
+/// show the same context like the file where an error occurred, this tries
+/// to avoid showing redundant data in the entry.
+void _log(LogEntry entry) {
+  messageMentions(String text) {
+    return entry.message.toLowerCase().contains(text.toLowerCase());
+  }
+
+  var prefixParts = [];
+
+  // Show the level (unless the message mentions it).
+  if (!messageMentions(entry.level.name)) {
+    prefixParts.add("${entry.level} from");
+  }
+
+  // Show the transformer.
+  prefixParts.add(entry.transform.transformer);
+
+  // Mention the primary input of the transform unless the message seems to.
+  if (!messageMentions(entry.transform.primaryId.path)) {
+    prefixParts.add("on ${entry.transform.primaryId}");
+  }
+
+  // If the relevant asset isn't the primary input, mention it unless the
+  // message already does.
+  if (entry.assetId != entry.transform.primaryId &&
+      !messageMentions(entry.assetId.path)) {
+    prefixParts.add("with input ${entry.assetId}");
+  }
+
+  var prefix = "[${prefixParts.join(' ')}]:";
+  var message = entry.message;
+  if (entry.span != null) {
+    message = entry.span.getLocationMessage(entry.message);
+  }
+
+  switch (entry.level) {
+    case LogLevel.ERROR:
+      log.error("${log.red(prefix)}\n$message");
+      break;
+
+    case LogLevel.WARNING:
+      log.warning("${log.yellow(prefix)}\n$message");
+      break;
+
+    case LogLevel.INFO:
+      log.message("${log.cyan(prefix)}\n$message");
+      break;
+  }
+}
+
+/// An enum describing different modes of constructing a [DirectoryWatcher].
+abstract class WatcherType {
+  /// A watcher that automatically chooses its type based on the operating
+  /// system.
+  static const AUTO = const _AutoWatcherType();
+
+  /// A watcher that always polls the filesystem for changes.
+  static const POLLING = const _PollingWatcherType();
+
+  /// No directory watcher at all.
+  static const NONE = const _NoneWatcherType();
+
+  /// Creates a new DirectoryWatcher.
+  DirectoryWatcher create(String directory);
+
+  String toString();
+}
+
+class _AutoWatcherType implements WatcherType {
+  const _AutoWatcherType();
+
+  DirectoryWatcher create(String directory) =>
+    new DirectoryWatcher(directory);
+
+  String toString() => "auto";
+}
+
+class _PollingWatcherType implements WatcherType {
+  const _PollingWatcherType();
+
+  DirectoryWatcher create(String directory) =>
+    new PollingDirectoryWatcher(directory);
+
+  String toString() => "polling";
+}
+
+class _NoneWatcherType implements WatcherType {
+  const _NoneWatcherType();
+
+  DirectoryWatcher create(String directory) => null;
+
+  String toString() => "none";
+}