Move a bunch of src/ files into subdirectories.

lib/src/loader.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.
-
-library unittest.loader;
-
-import 'dart:async';
-import 'dart:io';
-import 'dart:isolate';
-
-import 'package:path/path.dart' as p;
-
-import 'dart.dart';
-import 'io.dart';
-import 'isolate_test.dart';
-import 'load_exception.dart';
-import 'remote_exception.dart';
-import 'suite.dart';
-
-/// A class for finding test files and loading them into a runnable form.
-class Loader {
-  /// The package root to use for loading tests, or `null` to use the automatic
-  /// root.
-  final String _packageRoot;
-
-  /// All isolates that have been spun up by the loader.
-  final _isolates = new Set<Isolate>();
-
-  /// Creates a new loader.
-  ///
-  /// If [packageRoot] is passed, it's used as the package root for all loaded
-  /// tests. Otherwise, the `packages/` directories next to the test entrypoints
-  /// will be used.
-  Loader({String packageRoot})
-      : _packageRoot = packageRoot;
-
-  /// Loads all test suites in [dir].
-  ///
-  /// This will load tests from files that end in "_test.dart".
-  Future<Set<Suite>> loadDir(String dir) {
-    return Future.wait(new Directory(dir).listSync(recursive: true)
-        .map((entry) {
-      if (entry is! File) return new Future.value();
-      if (!entry.path.endsWith("_test.dart")) return new Future.value();
-      if (p.split(entry.path).contains('packages')) return new Future.value();
-
-      // TODO(nweiz): Provide a way for the caller to gracefully handle some
-      // isolates failing to load without stopping the rest.
-      return loadFile(entry.path);
-    })).then((suites) => suites.toSet()..remove(null));
-  }
-
-  /// Loads a test suite from the file at [path].
-  ///
-  /// This will throw a [LoadException] if the file fails to load.
-  Future<Suite> loadFile(String path) {
-    // TODO(nweiz): Support browser tests.
-    var packageRoot = _packageRoot == null
-        ? p.join(p.dirname(path), 'packages')
-        : _packageRoot;
-
-    if (!new Directory(packageRoot).existsSync()) {
-      throw new LoadException(path, "Directory $packageRoot does not exist.");
-    }
-
-    var receivePort = new ReceivePort();
-    return runInIsolate('''
-import "package:unittest/src/vm_listener.dart";
-
-import "${p.toUri(p.absolute(path))}" as test;
-
-void main(_, Map message) {
-  var sendPort = message['reply'];
-  VmListener.start(sendPort, () => test.main);
-}
-''', {
-      'reply': receivePort.sendPort
-    }, packageRoot: packageRoot).catchError((error, stackTrace) {
-      receivePort.close();
-      return new Future.error(new LoadException(path, error), stackTrace);
-    }).then((isolate) {
-      _isolates.add(isolate);
-      return receivePort.first;
-    }).then((response) {
-      if (response["type"] == "loadException") {
-        return new Future.error(new LoadException(path, response["message"]));
-      } else if (response["type"] == "error") {
-        var asyncError = RemoteException.deserialize(response["error"]);
-        return new Future.error(
-            new LoadException(path, asyncError.error),
-            asyncError.stackTrace);
-      }
-
-      return new Suite(path, response["tests"].map((test) {
-        return new IsolateTest(test['name'], test['sendPort']);
-      }));
-    });
-  }
-
-  /// Closes the loader and releases all resources allocated by it.
-  Future close() {
-    for (var isolate in _isolates) {
-      isolate.kill();
-    }
-    _isolates.clear();
-    return new Future.value();
-  }
-}