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dchaibRolandPheasant
dchaib
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RolandPheasant
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Remove from transform many with projection (#265)
* Add failing unit tests * Add an equality comparer in IChangeSet for lists * Pass the equality comparer to the Clone method directly from TransformMany instead of using IChangeSet * Add equality comparer to other calls to Clone method in TransformMany * Bump minor version
1 parent 2b19227 commit 0e1a9fe

4 files changed

Lines changed: 220 additions & 9 deletions

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‎src/DynamicData.Tests/List/TransformManyProjectionFixture.cs‎

Lines changed: 168 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,168 @@
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using DynamicData.Aggregation;
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using DynamicData.Binding;
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using FluentAssertions;
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using System;
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using System.Collections.Generic;
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using System.Collections.ObjectModel;
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using System.Linq;
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using System.Text;
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using Xunit;
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namespace DynamicData.Tests.List
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{
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public class TransformManyProjectionFixture : IDisposable
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{
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private readonly ISourceList<ClassWithNestedObservableCollection> _source;
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private readonly IObservableList<ProjectedNestedChild> _results;
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public TransformManyProjectionFixture()
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{
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_source = new SourceList<ClassWithNestedObservableCollection>();
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_results = _source.Connect()
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.AutoRefreshOnObservable(self => self.Children.ToObservableChangeSet())
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.TransformMany(parent => parent.Children.Select(c => new ProjectedNestedChild(parent, c)), new ProjectNestedChildEqualityComparer())
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.AsObservableList();
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}
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public void Dispose()
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{
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_source.Dispose();
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}
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[Fact]
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public void AddRange()
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{
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var children = new[]
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{
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new NestedChild("A", "ValueA"),
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new NestedChild("B", "ValueB"),
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new NestedChild("C", "ValueC"),
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new NestedChild("D", "ValueD"),
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new NestedChild("E", "ValueE"),
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new NestedChild("F", "ValueF")
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};
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var parents = new[]
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{
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new ClassWithNestedObservableCollection(1, new[] { children[0], children[1] }),
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new ClassWithNestedObservableCollection(2, new[] { children[2], children[3] }),
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new ClassWithNestedObservableCollection(3, new[] { children[4] })
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};
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_source.AddRange(parents);
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_results.Count.Should().Be(5);
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_results.Items.ShouldBeEquivalentTo(parents.SelectMany(p => p.Children.Take(5).Select(c => new ProjectedNestedChild(p, c))));
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}
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[Fact]
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public void RemoveParent()
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{
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var children = new[]
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{
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new NestedChild("A", "ValueA"),
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new NestedChild("B", "ValueB"),
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new NestedChild("C", "ValueC"),
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new NestedChild("D", "ValueD"),
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new NestedChild("E", "ValueE"),
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new NestedChild("F", "ValueF")
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};
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var parents = new[]
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{
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new ClassWithNestedObservableCollection(1, new[] { children[0], children[1] }),
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new ClassWithNestedObservableCollection(2, new[] { children[2], children[3] }),
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new ClassWithNestedObservableCollection(3, new[] { children[4] })
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};
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_source.AddRange(parents);
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//remove a parent and check children have moved
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_source.Remove(parents[0]);
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_results.Count.Should().Be(3);
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_results.Items.ShouldBeEquivalentTo(parents.Skip(1).SelectMany(p => p.Children.Select(c => new ProjectedNestedChild(p, c))));
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}
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[Fact]
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public void RemoveChild()
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{
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var children = new[]
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{
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new NestedChild("A", "ValueA"),
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new NestedChild("B", "ValueB"),
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new NestedChild("C", "ValueC"),
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new NestedChild("D", "ValueD"),
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new NestedChild("E", "ValueE"),
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new NestedChild("F", "ValueF")
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};
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var parents = new[]
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{
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new ClassWithNestedObservableCollection(1, new[] { children[0], children[1] }),
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new ClassWithNestedObservableCollection(2, new[] { children[2], children[3] }),
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new ClassWithNestedObservableCollection(3, new[] { children[4] })
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};
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_source.AddRange(parents);
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//remove a child
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parents[1].Children.Remove(children[3]);
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_results.Count.Should().Be(4);
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_results.Items.ShouldBeEquivalentTo(parents.SelectMany(p => p.Children.Where(child => child.Name != "D").Select(c => new ProjectedNestedChild(p, c))));
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}
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private class ProjectedNestedChild
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{
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public ClassWithNestedObservableCollection Parent { get; }
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public NestedChild Child { get; }
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public ProjectedNestedChild(ClassWithNestedObservableCollection parent, NestedChild child)
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{
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Parent = parent;
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Child = child;
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}
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}
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private class ProjectNestedChildEqualityComparer : IEqualityComparer<ProjectedNestedChild>
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{
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public bool Equals(ProjectedNestedChild x, ProjectedNestedChild y)
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{
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if (x == null || y == null)
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return false;
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return x.Child.Name == y.Child.Name;
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}
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public int GetHashCode(ProjectedNestedChild obj)
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{
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return obj.Child.Name.GetHashCode();
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}
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}
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private class NestedChild
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{
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public string Name { get; }
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public string Value { get; }
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public NestedChild(string name, string value)
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{
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Name = name;
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Value = value;
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}
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}
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private class ClassWithNestedObservableCollection
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{
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public int Id { get; }
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public ObservableCollection<NestedChild> Children { get; }
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public ClassWithNestedObservableCollection(int id, IEnumerable<NestedChild> animals)
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{
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Id = id;
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Children = new ObservableCollection<NestedChild>(animals);
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}
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}
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}
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}

‎src/DynamicData/List/Internal/TransformMany.cs‎

Lines changed: 19 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -93,8 +93,23 @@ public IObservable<IChangeSet<TDestination>> Run()
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return CreateWithChangeset();
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}
9595

96-
return _source.Transform(item => new ManyContainer(_manyselector(item).ToArray()), true)
97-
.Select(changes => new ChangeSet<TDestination>(new DestinationEnumerator(changes, _equalityComparer))).NotEmpty();
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return Observable.Create<IChangeSet<TDestination>>(observer =>
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{
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//NB: ChangeAwareList is used internally by dd to capture changes to a list and ensure they can be replayed by subsequent operators
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var result = new ChangeAwareList<TDestination>();
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return _source.Transform(item => new ManyContainer(_manyselector(item).ToArray()), true)
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.Select(changes =>
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{
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var destinationChanges = new ChangeSet<TDestination>(new DestinationEnumerator(changes, _equalityComparer));
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result.Clone(destinationChanges, _equalityComparer);
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return result.CaptureChanges();
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})
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.NotEmpty()
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.SubscribeSafe(observer);
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}
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);
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}
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private IObservable<IChangeSet<TDestination>> CreateWithChangeset()
@@ -123,15 +138,15 @@ private IObservable<IChangeSet<TDestination>> CreateWithChangeset()
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var init = intial.Select(changes =>
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{
126-
result.Clone(changes);
141+
result.Clone(changes, _equalityComparer);
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return result.CaptureChanges();
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});
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130145
var subseq = subsequent
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.RemoveIndex()
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.Select(changes =>
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{
134-
result.Clone(changes);
149+
result.Clone(changes, _equalityComparer);
135150
return result.CaptureChanges();
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});
137152

‎src/DynamicData/List/ListEx.cs‎

Lines changed: 32 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -45,6 +45,23 @@ internal static bool MovedWithinRange<T>(this Change<T> source, int startIndex,
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/// changes
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/// </exception>
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public static void Clone<T>(this IList<T> source, IChangeSet<T> changes)
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{
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Clone(source, changes, null);
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}
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/// <summary>
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/// Clones the list from the specified change set
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/// </summary>
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/// <typeparam name="T"></typeparam>
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/// <param name="source">The source.</param>
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/// <param name="changes">The changes.</param>
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/// <param name="equalityComparer">An equality comparer to match items in the changes.</param>
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/// <exception cref="System.ArgumentNullException">
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/// source
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/// or
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/// changes
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/// </exception>
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public static void Clone<T>(this IList<T> source, IChangeSet<T> changes, IEqualityComparer<T> equalityComparer)
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{
4966
if (source == null)
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{
@@ -58,11 +75,11 @@ public static void Clone<T>(this IList<T> source, IChangeSet<T> changes)
5875

5976
foreach (var item in changes)
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{
61-
Clone(source, item);
78+
Clone(source, item, equalityComparer ?? EqualityComparer<T>.Default);
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}
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}
6481

65-
private static void Clone<T>(this IList<T> source, Change<T> item)
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private static void Clone<T>(this IList<T> source, Change<T> item, IEqualityComparer<T> equalityComparer)
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{
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var changeAware = source as ChangeAwareList<T>;
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@@ -154,8 +171,19 @@ private static void Clone<T>(this IList<T> source, Change<T> item)
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source.RemoveAt(change.CurrentIndex);
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}
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else
157-
{
158-
source.Remove(change.Current);
174+
{
175+
if (equalityComparer != null)
176+
{
177+
int index = source.IndexOf(change.Current, equalityComparer);
178+
if (index > -1)
179+
{
180+
source.RemoveAt(index);
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}
182+
}
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else
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{
185+
source.Remove(change.Current);
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}
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}
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161189
break;

‎version.json‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
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{
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"version": "6.12",
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"version": "6.13",
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"publicReleaseRefSpec": [
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"^refs/heads/master$", // we release out of master
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"^refs/heads/preview/.*", // we release previews

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