Move PathObserver to mdv_observe package

tests/html/path_observer_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:html' show PathObserver;
-import 'package:unittest/html_config.dart';
-import 'package:mdv_observe/mdv_observe.dart';
-import 'package:unittest/unittest.dart';
-
-// This file contains code ported from:
-// https://github.com/rafaelw/ChangeSummary/blob/master/tests/test.js
-
-main() {
-  useHtmlConfiguration();
-  group('PathObserver', observePathTests);
-}
-
-observePath(obj, path) => new PathObserver(obj, path);
-
-sym(x) => new Symbol(x);
-
-toSymbolMap(Map map) {
-  var result = new ObservableMap.linked();
-  map.forEach((key, value) {
-    if (value is Map) value = toSymbolMap(value);
-    result[new Symbol(key)] = value;
-  });
-  return result;
-}
-
-observePathTests() {
-
-  test('Degenerate Values', () {
-    expect(observePath(null, '').value, null);
-    expect(observePath(123, '').value, 123);
-    expect(observePath(123, 'foo.bar.baz').value, null);
-
-    // shouldn't throw:
-    observePath(123, '').values.listen((_) {}).cancel();
-    observePath(null, '').value = null;
-    observePath(123, '').value = 42;
-    observePath(123, 'foo.bar.baz').value = 42;
-
-    var foo = {};
-    expect(observePath(foo, '').value, foo);
-
-    foo = new Object();
-    expect(observePath(foo, '').value, foo);
-
-    expect(observePath(foo, 'a/3!').value, null);
-  });
-
-  test('get value at path ObservableBox', () {
-    var obj = new ObservableBox(new ObservableBox(new ObservableBox(1)));
-
-    expect(observePath(obj, '').value, obj);
-    expect(observePath(obj, 'value').value, obj.value);
-    expect(observePath(obj, 'value.value').value, obj.value.value);
-    expect(observePath(obj, 'value.value.value').value, 1);
-
-    obj.value.value.value = 2;
-    expect(observePath(obj, 'value.value.value').value, 2);
-
-    obj.value.value = new ObservableBox(3);
-    expect(observePath(obj, 'value.value.value').value, 3);
-
-    obj.value = new ObservableBox(4);
-    expect(observePath(obj, 'value.value.value').value, null);
-    expect(observePath(obj, 'value.value').value, 4);
-  });
-
-
-  test('get value at path ObservableMap', () {
-    var obj = toSymbolMap({'a': {'b': {'c': 1}}});
-
-    expect(observePath(obj, '').value, obj);
-    expect(observePath(obj, 'a').value, obj[sym('a')]);
-    expect(observePath(obj, 'a.b').value, obj[sym('a')][sym('b')]);
-    expect(observePath(obj, 'a.b.c').value, 1);
-
-    obj[sym('a')][sym('b')][sym('c')] = 2;
-    expect(observePath(obj, 'a.b.c').value, 2);
-
-    obj[sym('a')][sym('b')] = toSymbolMap({'c': 3});
-    expect(observePath(obj, 'a.b.c').value, 3);
-
-    obj[sym('a')] = toSymbolMap({'b': 4});
-    expect(observePath(obj, 'a.b.c').value, null);
-    expect(observePath(obj, 'a.b').value, 4);
-  });
-
-  test('set value at path', () {
-    var obj = toSymbolMap({});
-    observePath(obj, 'foo').value = 3;
-    expect(obj[sym('foo')], 3);
-
-    var bar = toSymbolMap({ 'baz': 3 });
-    observePath(obj, 'bar').value = bar;
-    expect(obj[sym('bar')], bar);
-
-    observePath(obj, 'bar.baz.bat').value = 'not here';
-    expect(observePath(obj, 'bar.baz.bat').value, null);
-  });
-
-  test('set value back to same', () {
-    var obj = toSymbolMap({});
-    var path = observePath(obj, 'foo');
-    var values = [];
-    path.values.listen((v) { values.add(v); });
-
-    path.value = 3;
-    expect(obj[sym('foo')], 3);
-    expect(path.value, 3);
-
-    observePath(obj, 'foo').value = 2;
-    deliverChangeRecords();
-    expect(path.value, 2);
-    expect(observePath(obj, 'foo').value, 2);
-
-    observePath(obj, 'foo').value = 3;
-    deliverChangeRecords();
-    expect(path.value, 3);
-
-    deliverChangeRecords();
-    expect(values, [2, 3]);
-  });
-
-  test('Observe and Unobserve - Paths', () {
-    var arr = toSymbolMap({});
-
-    arr[sym('foo')] = 'bar';
-    var fooValues = [];
-    var fooPath = observePath(arr, 'foo');
-    var fooSub = fooPath.values.listen((v) {
-      fooValues.add(v);
-    });
-    arr[sym('foo')] = 'baz';
-    arr[sym('bat')] = 'bag';
-    var batValues = [];
-    var batPath = observePath(arr, 'bat');
-    var batSub = batPath.values.listen((v) {
-      batValues.add(v);
-    });
-
-    deliverChangeRecords();
-    expect(fooValues, ['baz']);
-    expect(batValues, []);
-
-    arr[sym('foo')] = 'bar';
-    fooSub.cancel();
-    arr[sym('bat')] = 'boo';
-    batSub.cancel();
-    arr[sym('bat')] = 'boot';
-
-    deliverChangeRecords();
-    expect(fooValues, ['baz']);
-    expect(batValues, []);
-  });
-
-  test('Path Value With Indices', () {
-    var model = toObservable([]);
-    observePath(model, '0').values.listen(expectAsync1((v) {
-      expect(v, 123);
-    }));
-    model.add(123);
-  });
-
-  test('Path Observation', () {
-    var model = new TestModel(const Symbol('a'),
-        new TestModel(const Symbol('b'),
-            new TestModel(const Symbol('c'), 'hello, world')));
-
-    var path = observePath(model, 'a.b.c');
-    var lastValue = null;
-    var sub = path.values.listen((v) { lastValue = v; });
-
-    model.value.value.value = 'hello, mom';
-
-    expect(lastValue, null);
-    deliverChangeRecords();
-    expect(lastValue, 'hello, mom');
-
-    model.value.value = new TestModel(const Symbol('c'), 'hello, dad');
-    deliverChangeRecords();
-    expect(lastValue, 'hello, dad');
-
-    model.value = new TestModel(const Symbol('b'),
-        new TestModel(const Symbol('c'), 'hello, you'));
-    deliverChangeRecords();
-    expect(lastValue, 'hello, you');
-
-    model.value.value = 1;
-    deliverChangeRecords();
-    expect(lastValue, null);
-
-    // Stop observing
-    sub.cancel();
-
-    model.value.value = new TestModel(const Symbol('c'),
-        'hello, back again -- but not observing');
-    deliverChangeRecords();
-    expect(lastValue, null);
-
-    // Resume observing
-    sub = path.values.listen((v) { lastValue = v; });
-
-    model.value.value.value = 'hello. Back for reals';
-    deliverChangeRecords();
-    expect(lastValue, 'hello. Back for reals');
-  });
-
-  test('observe map', () {
-    var model = toSymbolMap({'a': 1});
-    var path = observePath(model, 'a');
-
-    var values = [path.value];
-    var sub = path.values.listen((v) { values.add(v); });
-    expect(values, [1]);
-
-    model[sym('a')] = 2;
-    deliverChangeRecords();
-    expect(values, [1, 2]);
-
-    sub.cancel();
-    model[sym('a')] = 3;
-    deliverChangeRecords();
-    expect(values, [1, 2]);
-  });
-}
-
-class TestModel extends ObservableBase {
-  final Symbol fieldName;
-  var _value;
-
-  TestModel(this.fieldName, [initialValue]) : _value = initialValue;
-
-  get value => _value;
-
-  void set value(newValue) {
-    _value = notifyPropertyChange(fieldName, _value, newValue);
-  }
-
-  getValueWorkaround(key) {
-    if (key == fieldName) return value;
-    return null;
-  }
-  void setValueWorkaround(key, newValue) {
-    if (key == fieldName) value = newValue;
-  }
-
-  toString() => '#<$runtimeType $fieldName: $_value>';
-}
-
-_record(key, oldValue, newValue, [kind = ChangeRecord.FIELD]) =>
-    new ChangeRecord(key, oldValue, newValue, kind: kind);