Add FileSystemWatcher class to dart:io.

tests/standalone/io/file_system_watcher_test.dart

+// Copyright (c) 2013, 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.
+
+import "dart:async";
+import "package:expect/expect.dart";
+import "dart:io";
+import "dart:isolate";
+
+
+void testWatchCreateFile() {
+  var dir = new Directory('').createTempSync();
+  var file = new File(dir.path + '/file');
+
+  var watcher = dir.watch();
+
+  var port = new ReceivePort();
+  var sub;
+  sub = watcher.listen((event) {
+    if (event is FileSystemCreateEvent &&
+        event.path.endsWith('file')) {
+      port.close();
+      sub.cancel();
+      dir.deleteSync(recursive: true);

[Søren Gjesse, 2013/08/26 07:51:55]

Failure for all other events (for all tests)?

[Anders Johnsen, 2013/09/03 11:36:23]

Sadly, no. I had this, but some platforms put in extra events. I prefer keeping
as such, instead of making it platform specific.

+    }

[Søren Gjesse, 2013/08/26 07:51:55]

Add an onDone handler and expect it no be called (for all tests).

[Anders Johnsen, 2013/09/03 11:36:23]

As we stop it by canceling the subscription, there can't be an onDone by
definition. It should be tested in async, not here.

+  }, onError: (e) {
+    dir.deleteSync(recursive: true);
+    throw e;
+  });
+
+  file.createSync();
+}
+
+
+void testWatchModifyFile() {
+  var dir = new Directory('').createTempSync();
+  var file = new File(dir.path + '/file');
+  file.createSync();
+
+  var watcher = dir.watch();
+
+  var port = new ReceivePort();
+  var sub;
+  sub = watcher.listen((event) {
+    if (event is FileSystemModifyEvent) {
+      Expect.isTrue(event.path.endsWith('file'));
+      sub.cancel();
+      port.close();
+      dir.deleteSync(recursive: true);
+    }
+  }, onError: (e) {
+    dir.deleteSync(recursive: true);
+    throw e;
+  });
+
+  file.writeAsStringSync('a');
+}
+
+
+void testWatchMoveFile() {
+  var dir = new Directory('').createTempSync();
+  var file = new File(dir.path + '/file');
+  file.createSync();
+
+  var watcher = dir.watch();
+
+  var port = new ReceivePort();
+  var sub;
+  sub = watcher.listen((event) {
+    if (event is FileSystemMoveEvent) {
+      Expect.isTrue(event.path.endsWith('file'));
+      Expect.isTrue(event.destination.endsWith('file2'));
+      sub.cancel();
+      port.close();
+      dir.deleteSync(recursive: true);
+    }
+  }, onError: (e) {
+    dir.deleteSync(recursive: true);
+    throw e;
+  });
+
+  file.renameSync(dir.path + '/file2');
+}
+
+
+void testWatchDeleteFile() {
+  var dir = new Directory('').createTempSync();
+  var file = new File(dir.path + '/file');
+  file.createSync();
+
+  var watcher = dir.watch();
+
+  var port = new ReceivePort();
+  var sub;
+  sub = watcher.listen((event) {
+    if (event is FileSystemDeleteEvent) {
+      Expect.isTrue(event.path.endsWith('file'));
+      sub.cancel();
+      port.close();
+      dir.deleteSync(recursive: true);
+    }
+  }, onDone: () {
+    Expect.isTrue(gotEvent);
+  }, onError: (e) {
+    dir.deleteSync(recursive: true);
+    throw e;
+  });
+
+  file.deleteSync();
+}
+
+
+void testWatchOnlyModifyFile() {
+  var dir = new Directory('').createTempSync();
+  var file = new File(dir.path + '/file');
+
+  var watcher = dir.watch(events: FileSystemEvent.MODIFY_EVENT);
+
+  var port = new ReceivePort();
+  var sub;
+  sub = watcher.listen((event) {
+    Expect.isTrue(event is FileSystemModifyEvent);
+    Expect.isTrue(event.path.endsWith('file'));
+    sub.cancel();
+    port.close();
+    dir.deleteSync(recursive: true);
+  }, onError: (e) {
+    dir.deleteSync(recursive: true);
+    throw e;
+  });
+
+  file.createSync();
+  file.writeAsStringSync('a');
+}
+
+
+void testMultipleEvents() {
+  var dir = new Directory('').createTempSync();
+  var file = new File(dir.path + '/file');
+  var file2 = new File(dir.path + '/file2');
+
+  var watcher = dir.watch();
+
+  var port = new ReceivePort();
+  int state = 0;
+  var sub;
+  sub = watcher.listen((event) {
+    switch (state) {
+      case 0:
+        Expect.isTrue(event is FileSystemCreateEvent);
+        state = 1;
+        break;
+
+      case 1:
+        if (event is FileSystemCreateEvent) break;
+        Expect.isTrue(event is FileSystemModifyEvent);
+        state = 2;
+        break;
+
+      case 2:
+        if (event is FileSystemModifyEvent) break;
+        Expect.isTrue(event is FileSystemMoveEvent);
+        state = 3;
+        break;
+
+      case 3:
+        if (event is FileSystemMoveEvent) break;
+        Expect.isTrue(event is FileSystemDeleteEvent);
+        sub.cancel();
+        port.close();
+        dir.deleteSync();
+        break;
+    }
+  });
+
+  file.createSync();
+  file.writeAsStringSync('a');
+  file.renameSync(file2.path);
+  file2.deleteSync();
+}
+
+
+void main() {
+  testWatchCreateFile();
+  testWatchModifyFile();
+  testWatchMoveFile();
+  testWatchDeleteFile();
+  testWatchOnlyModifyFile();
+  testMultipleEvents();
+}