test/observable_list_test.dart

// Copyright (c) 2016, 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:observable/observable.dart';
import 'package:test/test.dart';

import 'observable_test_utils.dart';

main() => _runTests();

_runTests() {
  // TODO(jmesserly): need all standard List API tests.

  StreamSubscription sub, sub2;

  sharedTearDown() {
    list = null;
    sub.cancel();
    if (sub2 != null) {
      sub2.cancel();
      sub2 = null;
    }
  }

  group('observe length', () {
    ObservableList list;
    List<ChangeRecord> changes;

    setUp(() {
      list = toObservable([1, 2, 3]) as ObservableList;
      changes = null;
      sub = list.changes.listen((records) {
        changes = getPropertyChangeRecords(records, #length);
      });
    });

    tearDown(sharedTearDown);

    test('add changes length', () {
      list.add(4);
      expect(list, [1, 2, 3, 4]);
      return new Future(() {
        expectChanges(changes, [_lengthChange(3, 4)]);
      });
    });

    test('removeObject changes length', () {
      list.remove(2);
      expect(list, orderedEquals([1, 3]));

      return new Future(() {
        expectChanges(changes, [_lengthChange(3, 2)]);
      });
    });

    test('removeRange changes length', () {
      list.add(4);
      list.removeRange(1, 3);
      expect(list, [1, 4]);
      return new Future(() {
        expectChanges(changes, [_lengthChange(3, 4), _lengthChange(4, 2)]);
      });
    });

    test('removeWhere changes length', () {
      list.add(2);
      list.removeWhere((e) => e == 2);
      expect(list, [1, 3]);
      return new Future(() {
        expectChanges(changes, [_lengthChange(3, 4), _lengthChange(4, 2)]);
      });
    });

    test('length= changes length', () {
      list.length = 5;
      expect(list, [1, 2, 3, null, null]);
      return new Future(() {
        expectChanges(changes, [_lengthChange(3, 5)]);
      });
    });

    test('[]= does not change length', () {
      list[2] = 9000;
      expect(list, [1, 2, 9000]);
      return new Future(() {
        expectChanges(changes, null);
      });
    });

    test('clear changes length', () {
      list.clear();
      expect(list, []);
      return new Future(() {
        expectChanges(changes, [_lengthChange(3, 0)]);
      });
    });
  });

  group('observe index', () {
    List<ListChangeRecord> changes;

    setUp(() {
      list = toObservable([1, 2, 3]) as ObservableList;
      changes = null;
      sub = list.listChanges.listen((List<ListChangeRecord> records) {
        changes = getListChangeRecords(records, 1);
      });
    });

    tearDown(sharedTearDown);

    test('add does not change existing items', () {
      list.add(4);
      expect(list, [1, 2, 3, 4]);
      return new Future(() {
        expectChanges(changes, []);
      });
    });

    test('[]= changes item', () {
      list[1] = 777;
      expect(list, [1, 777, 3]);
      return new Future(() {
        expectChanges(changes, [
          _change(1, addedCount: 1, removed: [2])
        ]);
      });
    });

    test('[]= on a different item does not fire change', () {
      list[2] = 9000;
      expect(list, [1, 2, 9000]);
      return new Future(() {
        expectChanges(changes, []);
      });
    });

    test('set multiple times results in one change', () {
      list[1] = 777;
      list[1] = 42;
      expect(list, [1, 42, 3]);
      return new Future(() {
        expectChanges(changes, [
          _change(1, addedCount: 1, removed: [2]),
        ]);
      });
    });

    test('set length without truncating item means no change', () {
      list.length = 2;
      expect(list, [1, 2]);
      return new Future(() {
        expectChanges(changes, []);
      });
    });

    test('truncate removes item', () {
      list.length = 1;
      expect(list, [1]);
      return new Future(() {
        expectChanges(changes, [
          _change(1, removed: [2, 3])
        ]);
      });
    });

    test('truncate and add new item', () {
      list.length = 1;
      list.add(42);
      expect(list, [1, 42]);
      return new Future(() {
        expectChanges(changes, [
          _change(1, removed: [2, 3], addedCount: 1)
        ]);
      });
    });

    test('truncate and add same item', () {
      list.length = 1;
      list.add(2);
      expect(list, [1, 2]);
      return new Future(() {
        expectChanges(changes, []);
      });
    });
  });

  test('toString', () {
    var list = toObservable([1, 2, 3]);
    expect(list.toString(), '[1, 2, 3]');
  });

  group('change records', () {
    List<ChangeRecord> propRecords;
    List<ListChangeRecord> listRecords;

    setUp(() {
      list = toObservable([1, 2, 3, 1, 3, 4]) as ObservableList;
      propRecords = null;
      listRecords = null;
      sub = list.changes.listen((r) => propRecords = r);
      sub2 = list.listChanges.listen((r) => listRecords = r);
    });

    tearDown(sharedTearDown);

    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((int i) => copy.add(i));
      expect(copy, orderedEquals([1, 2, 3, 1, 3, 4]));
      return new Future(() {
        // no change from read-only operators
        expectChanges(propRecords, null);
        expectChanges(listRecords, null);
      });
    });

    test('add', () {
      list.add(5);
      list.add(6);
      expect(list, orderedEquals([1, 2, 3, 1, 3, 4, 5, 6]));

      return new Future(() {
        expectChanges(propRecords, [
          _lengthChange(6, 7),
          _lengthChange(7, 8),
        ]);
        expectChanges(listRecords, [_change(6, addedCount: 2)]);
      });
    });

    test('[]=', () {
      list[1] = list.last;
      expect(list, orderedEquals([1, 4, 3, 1, 3, 4]));

      return new Future(() {
        expectChanges(propRecords, null);
        expectChanges(listRecords, [
          _change(1, addedCount: 1, removed: [2])
        ]);
      });
    });

    test('removeLast', () {
      expect(list.removeLast(), 4);
      expect(list, orderedEquals([1, 2, 3, 1, 3]));

      return new Future(() {
        expectChanges(propRecords, [_lengthChange(6, 5)]);
        expectChanges(listRecords, [
          _change(5, removed: [4])
        ]);
      });
    });

    test('removeRange', () {
      list.removeRange(1, 4);
      expect(list, orderedEquals([1, 3, 4]));

      return new Future(() {
        expectChanges(propRecords, [_lengthChange(6, 3)]);
        expectChanges(listRecords, [
          _change(1, removed: [2, 3, 1])
        ]);
      });
    });

    test('removeWhere', () {
      list.removeWhere((e) => e == 3);
      expect(list, orderedEquals([1, 2, 1, 4]));

      return new Future(() {
        expectChanges(propRecords, [_lengthChange(6, 4)]);
        expectChanges(listRecords, [
          _change(2, removed: [3]),
          _change(3, removed: [3])
        ]);
      });
    });

    test('sort', () {
      list.sort((x, y) => x - y);
      expect(list, orderedEquals([1, 1, 2, 3, 3, 4]));

      return new Future(() {
        expectChanges(propRecords, null);
        expectChanges(listRecords, [
          _change(1, addedCount: 1),
          _change(4, removed: [1])
        ]);
      });
    });

    test('sort of 2 elements', () {
      var list = toObservable([3, 1]);
      // Dummy listener to record changes.
      // TODO(jmesserly): should we just record changes always, to support the sync api?
      sub = list.listChanges.listen((List<ListChangeRecord> records) => null)
          as StreamSubscription;
      list.sort();
      expect(list.deliverListChanges(), true);
      list.sort();
      expect(list.deliverListChanges(), false);
      list.sort();
      expect(list.deliverListChanges(), false);
    });

    test('clear', () {
      list.clear();
      expect(list, []);

      return new Future(() {
        expectChanges(propRecords, [
          _lengthChange(6, 0),
          new PropertyChangeRecord(list, #isEmpty, false, true),
          new PropertyChangeRecord(list, #isNotEmpty, true, false),
        ]);
        expectChanges(listRecords, [
          _change(0, removed: [1, 2, 3, 1, 3, 4])
        ]);
      });
    });
  });
}

ObservableList<int> list;

PropertyChangeRecord _lengthChange(int oldValue, int newValue) =>
    new PropertyChangeRecord(list, #length, oldValue, newValue);

_change(int index, {List removed: const [], int addedCount: 0}) =>
    new ListChangeRecord(list, index, removed: removed, addedCount: addedCount);