Implement Model-Driven-Views spec for Dart

pkg/mdv_observe/test/observable_list_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 'package:mdv_observe/mdv_observe.dart';
+import 'package:unittest/unittest.dart';
+import 'utils.dart';
+
+main() {
+  // TODO(jmesserly): need all standard List API tests.
+
+  const _LENGTH = const Symbol('length');
+
+  group('observe length', () {
+
+    ObservableList list;
+    List<ChangeRecord> changes;
+
+    setUp(() {
+      list = toObservable([1, 2, 3]);
+      changes = null;
+      list.changes.listen((records) {
+        changes = records.where((r) => r.changes(_LENGTH)).toList();
+      });
+    });
+
+    test('add changes length', () {
+      list.add(4);
+      expect(list, [1, 2, 3, 4]);
+      deliverChangeRecords();
+      expectChanges(changes, [_lengthChange]);
+    });
+
+    test('removeRange changes length', () {
+      list.add(4);
+      list.removeRange(1, 3);
+      expect(list, [1, 4]);
+      deliverChangeRecords();
+      expectChanges(changes, [_lengthChange]);
+    });
+
+    test('length= changes length', () {
+      list.length = 5;
+      expect(list, [1, 2, 3, null, null]);
+      deliverChangeRecords();
+      expectChanges(changes, [_lengthChange]);
+    });
+
+    test('[]= does not change length', () {
+      list[2] = 9000;
+      expect(list, [1, 2, 9000]);
+      deliverChangeRecords();
+      expectChanges(changes, []);
+    });
+
+    test('clear changes length', () {
+      list.clear();
+      expect(list, []);
+      deliverChangeRecords();
+      expectChanges(changes, [_lengthChange]);
+    });
+  });
+
+  group('observe index', () {
+    ObservableList list;
+    List<ChangeRecord> changes;
+
+    setUp(() {
+      list = toObservable([1, 2, 3]);
+      changes = null;
+      list.changes.listen((records) {
+        changes = records.where((r) => r.changes(1)).toList();
+      });
+    });
+
+    test('add does not change existing items', () {
+      list.add(4);
+      expect(list, [1, 2, 3, 4]);
+      deliverChangeRecords();
+      expectChanges(changes, []);
+    });
+
+    test('[]= changes item', () {
+      list[1] = 777;
+      expect(list, [1, 777, 3]);
+      deliverChangeRecords();
+      expectChanges(changes, [_change(1, addedCount: 1, removedCount: 1)]);
+    });
+
+    test('[]= on a different item does not fire change', () {
+      list[2] = 9000;
+      expect(list, [1, 2, 9000]);
+      deliverChangeRecords();
+      expectChanges(changes, []);
+    });
+
+    test('set multiple times results in one change', () {
+      list[1] = 777;
+      list[1] = 42;
+      expect(list, [1, 42, 3]);
+      deliverChangeRecords();
+      expectChanges(changes, [
+        _change(1, addedCount: 1, removedCount: 1),
+      ]);
+    });
+
+    test('set length without truncating item means no change', () {
+      list.length = 2;
+      expect(list, [1, 2]);
+      deliverChangeRecords();
+      expectChanges(changes, []);
+    });
+
+    test('truncate removes item', () {
+      list.length = 1;
+      expect(list, [1]);
+      deliverChangeRecords();
+      expectChanges(changes, [_change(1, removedCount: 2)]);
+    });
+
+    test('truncate and add new item', () {
+      list.length = 1;
+      list.add(42);
+      expect(list, [1, 42]);
+      deliverChangeRecords();
+      expectChanges(changes, [
+        _change(1, removedCount: 2, addedCount: 1)
+      ]);
+    });
+
+    test('truncate and add same item', () {
+      list.length = 1;
+      list.add(2);
+      expect(list, [1, 2]);
+      deliverChangeRecords();
+      expectChanges(changes, [
+        _change(1, removedCount: 2, addedCount: 1)
+      ]);
+    });
+  });
+
+  test('toString', () {
+    var list = toObservable([1, 2, 3]);
+    expect(list.toString(), '[1, 2, 3]');
+  });
+
+  group('change records', () {
+
+    List<ChangeRecord> records;
+    ObservableList list;
+
+    setUp(() {
+      list = toObservable([1, 2, 3, 1, 3, 4]);
+      records = null;
+      list.changes.listen((r) { records = r; });
+    });
+
+    test('read operations', () {
+      expect(list.length, 6);
+      expect(list[0], 1);
+      expect(list.indexOf(4), 5);
+      expect(list.indexOf(1), 0);
+      expect(list.indexOf(1, 1), 3);
+      expect(list.lastIndexOf(1), 3);
+      expect(list.last, 4);
+      var copy = new List<int>();
+      list.forEach((i) { copy.add(i); });
+      expect(copy, orderedEquals([1, 2, 3, 1, 3, 4]));
+      deliverChangeRecords();
+
+      // no change from read-only operators
+      expectChanges(records, null);
+    });
+
+    test('add', () {
+      list.add(5);
+      list.add(6);
+      expect(list, orderedEquals([1, 2, 3, 1, 3, 4, 5, 6]));
+
+      deliverChangeRecords();
+      expectChanges(records, [
+        _lengthChange,
+        _change(6, addedCount: 2)
+      ]);
+    });
+
+    test('[]=', () {
+      list[1] = list.last;
+      expect(list, orderedEquals([1, 4, 3, 1, 3, 4]));
+
+      deliverChangeRecords();
+      expectChanges(records, [ _change(1, addedCount: 1, removedCount: 1) ]);
+    });
+
+    test('removeLast', () {
+      expect(list.removeLast(), 4);
+      expect(list, orderedEquals([1, 2, 3, 1, 3]));
+
+      deliverChangeRecords();
+      expectChanges(records, [
+        _lengthChange,
+        _change(5, removedCount: 1)
+      ]);
+    });
+
+    test('removeRange', () {
+      list.removeRange(1, 4);
+      expect(list, orderedEquals([1, 3, 4]));
+
+      deliverChangeRecords();
+      expectChanges(records, [
+        _lengthChange,
+        _change(1, removedCount: 3),
+      ]);
+    });
+
+    test('sort', () {
+      list.sort((x, y) => x - y);
+      expect(list, orderedEquals([1, 1, 2, 3, 3, 4]));
+
+      deliverChangeRecords();
+      expectChanges(records, [
+        _change(1, addedCount: 5, removedCount: 5),
+      ]);
+    });
+
+    test('clear', () {
+      list.clear();
+      expect(list, []);
+
+      deliverChangeRecords();
+      expectChanges(records, [
+        _lengthChange,
+        _change(0, removedCount: 6)
+      ]);
+    });
+  });
+}
+
+const _LENGTH = const Symbol('length');
+
+final _lengthChange = new PropertyChangeRecord(_LENGTH);
+
+_change(index, {removedCount: 0, addedCount: 0}) => new ListChangeRecord(
+    index, removedCount: removedCount, addedCount: addedCount);