Fix MemoryFile to update last modified time when writeAs* is called (#50)

Author: tvolkert

CHANGELOG.md

@@ -1,3 +1,8 @@
+#### 2.3.1
+
+* Fixed `MemoryFileSystem` to make `File.writeAs...()` update the last modified
+  time of the file.
+
 #### 2.3.0
 
 * Added the following convenience methods in `Directory`:

lib/src/backends/memory/memory_file.dart

@@ -235,6 +235,7 @@ class _MemoryFile extends _MemoryFileSystemEntity implements File {
     _FileNode node = _resolvedBackingOrCreate;
     _truncateIfNecessary(node, mode);
     node.content.addAll(bytes);
+    node.touch();
   }
 
   @override

lib/src/backends/memory/node.dart

@@ -84,6 +84,11 @@ abstract class _RealNode extends _Node {
 
   /// The size of the file system entity in bytes.
   int get size;
+
+  /// Updates the last modified time of the node.
+  void touch() {
+    modified = new DateTime.now().millisecondsSinceEpoch;
+  }
 }
 
 /// Class that represents the backing for an in-memory directory.

pubspec.yaml

@@ -1,5 +1,5 @@
 name: file
-version: 2.3.0
+version: 2.3.1
 authors:
 - Matan Lurey <[email protected]>
 - Yegor Jbanov <[email protected]>

test/common_tests.dart

@@ -2492,6 +2492,15 @@ void runCommonTests(
           f.writeAsBytesSync(<int>[]);
           expect(f.readAsBytesSync(), <int>[]);
         });
+
+        test('updatesLastModifiedTime', () async {
+          File f = fs.file(ns('/foo'))..createSync();
+          DateTime before = f.statSync().modified;
+          await new Future<Null>.delayed(const Duration(seconds: 2));
+          f.writeAsBytesSync(<int>[1, 2, 3]);
+          DateTime after = f.statSync().modified;
+          expect(after, isAfter(before));
+        });
       });
 
       group('writeAsString', () {

test/utils.dart

@@ -36,6 +36,10 @@ Matcher isSameOrBefore(DateTime time) => new _IsSameOrBefore(time);
 /// the specified [time].
 Matcher isSameOrAfter(DateTime time) => new _IsSameOrAfter(time);
 
+/// Successfully matches against a [DateTime] that is after the specified
+/// [time].
+Matcher isAfter(DateTime time) => new _IsAfter(time);
+
 abstract class _CompareDateTime extends Matcher {
   final DateTime _time;
   final Matcher _matcher;
@@ -93,3 +97,13 @@ class _IsSameOrAfter extends _CompareDateTime {
   @override
   String get mismatchAdjective => 'before';
 }
+
+class _IsAfter extends _CompareDateTime {
+  const _IsAfter(DateTime time) : super(time, isPositive);
+
+  @override
+  String get descriptionOperator => '>';
+
+  @override
+  String get mismatchAdjective => 'before';
+}