Imported Upstream version 5.4.0.167

Former-commit-id: 5624ac747d633e885131e8349322922b6a59baaa

external/corefx/src/System.ObjectModel/dir.props

@@ -2,7 +2,8 @@
 <Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\dir.props" />
   <PropertyGroup>
-    <AssemblyVersion>4.1.0.0</AssemblyVersion>
+    <AssemblyVersion>4.1.1.0</AssemblyVersion>
+    <AssemblyKey>MSFT</AssemblyKey>
     <IsNETCoreApp>true</IsNETCoreApp>
     <IsUAP>true</IsUAP>
   </PropertyGroup>

external/corefx/src/System.ObjectModel/src/System/Collections/ObjectModel/KeyedCollection.cs

@@ -11,14 +11,17 @@ namespace System.Collections.ObjectModel
     [Serializable]
     [DebuggerTypeProxy(typeof(CollectionDebugView<>))]
     [DebuggerDisplay("Count = {Count}")]
+#if !MONO
+    [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, PublicKeyToken=b77a5c561934e089")]
+#endif
     public abstract class KeyedCollection<TKey, TItem> : Collection<TItem>
     {
         private const int defaultThreshold = 0;
 
-        private readonly IEqualityComparer<TKey> _comparer;
-        private Dictionary<TKey, TItem> _dict;
-        private int _keyCount;
-        private readonly int _threshold;
+        private readonly IEqualityComparer<TKey> comparer; // Do not rename (binary serialization)
+        private Dictionary<TKey, TItem> dict; // Do not rename (binary serialization)
+        private int keyCount; // Do not rename (binary serialization)
+        private readonly int threshold; // Do not rename (binary serialization)
 
         protected KeyedCollection() : this(null, defaultThreshold) { }
 
@@ -44,8 +47,8 @@ namespace System.Collections.ObjectModel
                 throw new ArgumentOutOfRangeException(nameof(dictionaryCreationThreshold), SR.ArgumentOutOfRange_InvalidThreshold);
             }
 
-            _comparer = comparer;
-            _threshold = dictionaryCreationThreshold;
+            this.comparer = comparer;
+            threshold = dictionaryCreationThreshold;
         }
 
         /// <summary>
@@ -65,7 +68,7 @@ namespace System.Collections.ObjectModel
         {
             get
             {
-                return _comparer;
+                return comparer;
             }
         }
 
@@ -90,14 +93,14 @@ namespace System.Collections.ObjectModel
                 throw new ArgumentNullException(nameof(key));
             }
 
-            if (_dict != null)
+            if (dict != null)
             {
-                return _dict.ContainsKey(key);
+                return dict.ContainsKey(key);
             }
 
             foreach (TItem item in Items)
             {
-                if (_comparer.Equals(GetKeyForItem(item), key)) return true;
+                if (comparer.Equals(GetKeyForItem(item), key)) return true;
             }
             return false;
         }
@@ -109,15 +112,15 @@ namespace System.Collections.ObjectModel
                 throw new ArgumentNullException(nameof(key));
             }
 
-            if (_dict != null)
+            if (dict != null)
             {
-                return _dict.TryGetValue(key, out item);
+                return dict.TryGetValue(key, out item);
             }
 
             foreach (TItem itemInItems in Items)
             {
                 TKey keyInItems = GetKeyForItem(itemInItems);
-                if (keyInItems != null && _comparer.Equals(key, keyInItems))
+                if (keyInItems != null && comparer.Equals(key, keyInItems))
                 {
                     item = itemInItems;
                     return true;
@@ -131,13 +134,13 @@ namespace System.Collections.ObjectModel
         private bool ContainsItem(TItem item)
         {
             TKey key;
-            if ((_dict == null) || ((key = GetKeyForItem(item)) == null))
+            if ((dict == null) || ((key = GetKeyForItem(item)) == null))
             {
                 return Items.Contains(item);
             }
 
             TItem itemInDict;
-            bool exist = _dict.TryGetValue(key, out itemInDict);
+            bool exist = dict.TryGetValue(key, out itemInDict);
             if (exist)
             {
                 return EqualityComparer<TItem>.Default.Equals(itemInDict, item);
@@ -152,15 +155,15 @@ namespace System.Collections.ObjectModel
                 throw new ArgumentNullException(nameof(key));
             }
 
-            if (_dict != null)
+            if (dict != null)
             {
                 TItem item;
-                return _dict.TryGetValue(key, out item) && Remove(item);
+                return dict.TryGetValue(key, out item) && Remove(item);
             }
 
             for (int i = 0; i < Items.Count; i++)
             {
-                if (_comparer.Equals(GetKeyForItem(Items[i]), key))
+                if (comparer.Equals(GetKeyForItem(Items[i]), key))
                 {
                     RemoveItem(i);
                     return true;
@@ -171,7 +174,7 @@ namespace System.Collections.ObjectModel
 
         protected IDictionary<TKey, TItem> Dictionary
         {
-            get { return _dict; }
+            get { return dict; }
         }
 
         protected void ChangeItemKey(TItem item, TKey newKey)
@@ -183,7 +186,7 @@ namespace System.Collections.ObjectModel
             }
 
             TKey oldKey = GetKeyForItem(item);
-            if (!_comparer.Equals(oldKey, newKey))
+            if (!comparer.Equals(oldKey, newKey))
             {
                 if (newKey != null)
                 {
@@ -200,12 +203,12 @@ namespace System.Collections.ObjectModel
         protected override void ClearItems()
         {
             base.ClearItems();
-            if (_dict != null)
+            if (dict != null)
             {
-                _dict.Clear();
+                dict.Clear();
             }
 
-            _keyCount = 0;
+            keyCount = 0;
         }
 
         protected abstract TKey GetKeyForItem(TItem item);
@@ -235,11 +238,11 @@ namespace System.Collections.ObjectModel
             TKey newKey = GetKeyForItem(item);
             TKey oldKey = GetKeyForItem(Items[index]);
 
-            if (_comparer.Equals(oldKey, newKey))
+            if (comparer.Equals(oldKey, newKey))
             {
-                if (newKey != null && _dict != null)
+                if (newKey != null && dict != null)
                 {
-                    _dict[newKey] = item;
+                    dict[newKey] = item;
                 }
             }
             else
@@ -259,14 +262,14 @@ namespace System.Collections.ObjectModel
 
         private void AddKey(TKey key, TItem item)
         {
-            if (_dict != null)
+            if (dict != null)
             {
-                _dict.Add(key, item);
+                dict.Add(key, item);
             }
-            else if (_keyCount == _threshold)
+            else if (keyCount == threshold)
             {
                 CreateDictionary();
-                _dict.Add(key, item);
+                dict.Add(key, item);
             }
             else
             {
@@ -275,19 +278,19 @@ namespace System.Collections.ObjectModel
                     throw new ArgumentException(SR.Format(SR.Argument_AddingDuplicate, key));
                 }
 
-                _keyCount++;
+                keyCount++;
             }
         }
 
         private void CreateDictionary()
         {
-            _dict = new Dictionary<TKey, TItem>(_comparer);
+            dict = new Dictionary<TKey, TItem>(comparer);
             foreach (TItem item in Items)
             {
                 TKey key = GetKeyForItem(item);
                 if (key != null)
                 {
-                    _dict.Add(key, item);
+                    dict.Add(key, item);
                 }
             }
         }
@@ -295,13 +298,13 @@ namespace System.Collections.ObjectModel
         private void RemoveKey(TKey key)
         {
             Debug.Assert(key != null, "key shouldn't be null!");
-            if (_dict != null)
+            if (dict != null)
             {
-                _dict.Remove(key);
+                dict.Remove(key);
             }
             else
             {
-                _keyCount--;
+                keyCount--;
             }
         }
     }

external/corefx/src/System.ObjectModel/src/System/Collections/ObjectModel/ObservableCollection.cs

@@ -6,6 +6,7 @@ using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Diagnostics;
+using System.Runtime.Serialization;
 
 namespace System.Collections.ObjectModel
 {
@@ -17,6 +18,9 @@ namespace System.Collections.ObjectModel
     [Serializable]
     [DebuggerTypeProxy(typeof(CollectionDebugView<>))]
     [DebuggerDisplay("Count = {Count}")]
+#if !MONO
+    [System.Runtime.CompilerServices.TypeForwardedFrom("WindowsBase, Version=3.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35")]
+#endif
     public class ObservableCollection<T> : Collection<T>, INotifyCollectionChanged, INotifyPropertyChanged
     {
         //------------------------------------------------------
@@ -238,12 +242,16 @@ namespace System.Collections.ObjectModel
             NotifyCollectionChangedEventHandler handler = CollectionChanged;
             if (handler != null)
             {
-                // Not calling BlockReentrancy() here to avoid the IDisposable box allocation.
+                // Not calling BlockReentrancy() here to avoid the SimpleMonitor allocation.
                 _blockReentrancyCount++;
-                using (new BlockReentrancyDisposable(this))
+                try
                 {
                     handler(this, e);
                 }
+                finally
+                {
+                    _blockReentrancyCount--;
+                }
             }
         }
 
@@ -263,8 +271,7 @@ namespace System.Collections.ObjectModel
         protected IDisposable BlockReentrancy()
         {
             _blockReentrancyCount++;
-            // Lazily box the struct as IDisposable once and reuse the same boxed instance with subsequent calls.
-            return _boxedBlockReentrancyDisposable ?? (_boxedBlockReentrancyDisposable = new BlockReentrancyDisposable(this));
+            return EnsureMonitorInitialized();
         }
 
         /// <summary> Check and assert for reentrant attempts to change this collection. </summary>
@@ -340,6 +347,25 @@ namespace System.Collections.ObjectModel
         {
             OnCollectionChanged(EventArgsCache.ResetCollectionChanged);
         }
+
+        private SimpleMonitor EnsureMonitorInitialized()
+        {
+            return _monitor ?? (_monitor = new SimpleMonitor(this));
+        }
+
+        [OnSerializing]
+        private void OnSerializing(StreamingContext context)
+        {
+            EnsureMonitorInitialized();
+            _monitor._busyCount = _blockReentrancyCount;
+        }
+
+        [OnDeserialized]
+        private void OnDeserialized(StreamingContext context)
+        {
+            _blockReentrancyCount = _monitor._busyCount;
+            _monitor._collection = this;
+        }
         #endregion Private Methods
 
         //------------------------------------------------------
@@ -351,17 +377,26 @@ namespace System.Collections.ObjectModel
         #region Private Types
 
         [Serializable]
-        private struct BlockReentrancyDisposable : IDisposable
+#if !MONO
+        [System.Runtime.CompilerServices.TypeForwardedFrom("WindowsBase, Version=3.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35")]
+#endif
+        private sealed class SimpleMonitor : IDisposable
         {
-            private readonly ObservableCollection<T> _collection;
+            internal int _busyCount; // Only used during (de)serialization to maintain compatibility with desktop.
 
-            public BlockReentrancyDisposable(ObservableCollection<T> collection)
+            [NonSerialized]
+            internal ObservableCollection<T> _collection;
+
+            public SimpleMonitor(ObservableCollection<T> collection)
             {
                 Debug.Assert(collection != null);
                 _collection = collection;
             }
 
-            public void Dispose() => _collection._blockReentrancyCount--;
+            public void Dispose()
+            {
+                _collection._blockReentrancyCount--;
+            }
         }
 
         #endregion Private Types
@@ -374,8 +409,10 @@ namespace System.Collections.ObjectModel
 
         #region Private Fields
 
+        private SimpleMonitor _monitor; // Lazily allocated only when a subclass calls BlockReentrancy() or during serialization.
+
+        [NonSerialized]
         private int _blockReentrancyCount;
-        private IDisposable _boxedBlockReentrancyDisposable; // Lazily allocated only when a subclass calls BlockReentrancy().
         #endregion Private Fields
     }
 

external/corefx/src/System.ObjectModel/src/System/Collections/ObjectModel/ReadOnlyDictionary.cs

@@ -13,9 +13,12 @@ namespace System.Collections.ObjectModel
     [Serializable]
     [DebuggerTypeProxy(typeof(DictionaryDebugView<,>))]
     [DebuggerDisplay("Count = {Count}")]
+#if !MONO
+    [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
+#endif
     public class ReadOnlyDictionary<TKey, TValue> : IDictionary<TKey, TValue>, IDictionary, IReadOnlyDictionary<TKey, TValue>
     {
-        private readonly IDictionary<TKey, TValue> _dictionary;
+        private readonly IDictionary<TKey, TValue> m_dictionary; // Do not rename (binary serialization)
         [NonSerialized]
         private Object _syncRoot;
         [NonSerialized]
@@ -30,12 +33,12 @@ namespace System.Collections.ObjectModel
                 throw new ArgumentNullException(nameof(dictionary));
             }
             Contract.EndContractBlock();
-            _dictionary = dictionary;
+            m_dictionary = dictionary;
         }
 
         protected IDictionary<TKey, TValue> Dictionary
         {
-            get { return _dictionary; }
+            get { return m_dictionary; }
         }
 
         public KeyCollection Keys
@@ -45,7 +48,7 @@ namespace System.Collections.ObjectModel
                 Contract.Ensures(Contract.Result<KeyCollection>() != null);
                 if (_keys == null)
                 {
-                    _keys = new KeyCollection(_dictionary.Keys);
+                    _keys = new KeyCollection(m_dictionary.Keys);
                 }
                 return _keys;
             }
@@ -58,7 +61,7 @@ namespace System.Collections.ObjectModel
                 Contract.Ensures(Contract.Result<ValueCollection>() != null);
                 if (_values == null)
                 {
-                    _values = new ValueCollection(_dictionary.Values);
+                    _values = new ValueCollection(m_dictionary.Values);
                 }
                 return _values;
             }
@@ -68,7 +71,7 @@ namespace System.Collections.ObjectModel
 
         public bool ContainsKey(TKey key)
         {
-            return _dictionary.ContainsKey(key);
+            return m_dictionary.ContainsKey(key);
         }
 
         ICollection<TKey> IDictionary<TKey, TValue>.Keys
@@ -81,7 +84,7 @@ namespace System.Collections.ObjectModel
 
         public bool TryGetValue(TKey key, out TValue value)
         {
-            return _dictionary.TryGetValue(key, out value);
+            return m_dictionary.TryGetValue(key, out value);
         }
 
         ICollection<TValue> IDictionary<TKey, TValue>.Values
@@ -96,7 +99,7 @@ namespace System.Collections.ObjectModel
         {
             get
             {
-                return _dictionary[key];
+                return m_dictionary[key];
             }
         }
 
@@ -114,7 +117,7 @@ namespace System.Collections.ObjectModel
         {
             get
             {
-                return _dictionary[key];
+                return m_dictionary[key];
             }
             set
             {
@@ -128,17 +131,17 @@ namespace System.Collections.ObjectModel
 
         public int Count
         {
-            get { return _dictionary.Count; }
+            get { return m_dictionary.Count; }
         }
 
         bool ICollection<KeyValuePair<TKey, TValue>>.Contains(KeyValuePair<TKey, TValue> item)
         {
-            return _dictionary.Contains(item);
+            return m_dictionary.Contains(item);
         }
 
         void ICollection<KeyValuePair<TKey, TValue>>.CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
         {
-            _dictionary.CopyTo(array, arrayIndex);
+            m_dictionary.CopyTo(array, arrayIndex);
         }
 
         bool ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly
@@ -167,7 +170,7 @@ namespace System.Collections.ObjectModel
 
         public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
         {
-            return _dictionary.GetEnumerator();
+            return m_dictionary.GetEnumerator();
         }
 
         #endregion
@@ -176,7 +179,7 @@ namespace System.Collections.ObjectModel
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
         {
-            return ((IEnumerable)_dictionary).GetEnumerator();
+            return ((IEnumerable)m_dictionary).GetEnumerator();
         }
 
         #endregion
@@ -209,12 +212,12 @@ namespace System.Collections.ObjectModel
 
         IDictionaryEnumerator IDictionary.GetEnumerator()
         {
-            IDictionary d = _dictionary as IDictionary;
+            IDictionary d = m_dictionary as IDictionary;
             if (d != null)
             {
                 return d.GetEnumerator();
             }
-            return new DictionaryEnumerator(_dictionary);
+            return new DictionaryEnumerator(m_dictionary);
         }
 
         bool IDictionary.IsFixedSize
@@ -294,14 +297,14 @@ namespace System.Collections.ObjectModel
             KeyValuePair<TKey, TValue>[] pairs = array as KeyValuePair<TKey, TValue>[];
             if (pairs != null)
             {
-                _dictionary.CopyTo(pairs, index);
+                m_dictionary.CopyTo(pairs, index);
             }
             else
             {
                 DictionaryEntry[] dictEntryArray = array as DictionaryEntry[];
                 if (dictEntryArray != null)
                 {
-                    foreach (var item in _dictionary)
+                    foreach (var item in m_dictionary)
                     {
                         dictEntryArray[index++] = new DictionaryEntry(item.Key, item.Value);
                     }
@@ -316,7 +319,7 @@ namespace System.Collections.ObjectModel
 
                     try
                     {
-                        foreach (var item in _dictionary)
+                        foreach (var item in m_dictionary)
                         {
                             objects[index++] = new KeyValuePair<TKey, TValue>(item.Key, item.Value);
                         }
@@ -340,7 +343,7 @@ namespace System.Collections.ObjectModel
             {
                 if (_syncRoot == null)
                 {
-                    ICollection c = _dictionary as ICollection;
+                    ICollection c = m_dictionary as ICollection;
                     if (c != null)
                     {
                         _syncRoot = c.SyncRoot;

external/corefx/src/System.ObjectModel/src/System/Collections/ObjectModel/ReadOnlyObservableCollection.cs

@@ -18,6 +18,9 @@ namespace System.Collections.ObjectModel
     [Serializable]
     [DebuggerTypeProxy(typeof(CollectionDebugView<>))]
     [DebuggerDisplay("Count = {Count}")]
+#if !MONO
+    [System.Runtime.CompilerServices.TypeForwardedFrom("WindowsBase, Version=3.0.0.0, Culture=Neutral, PublicKeyToken=31bf3856ad364e35")]
+#endif
     public class ReadOnlyObservableCollection<T> : ReadOnlyCollection<T>, INotifyCollectionChanged, INotifyPropertyChanged
     {
         #region Constructors

external/corefx/src/System.ObjectModel/tests/KeyedCollection/Serialization.cs

@@ -19,6 +19,7 @@ namespace System.Collections.ObjectModel.Tests
 
         [Theory]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Serialization still WIP in UapAot: https://github.com/dotnet/corefx/issues/18942")]
         public void SerializeDeserialize_Roundtrips(TestCollection c)
         {
             TestCollection clone = BinaryFormatterHelpers.Clone(c);

external/corefx/src/System.ObjectModel/tests/ObservableCollection/ObservableCollection_ConstructorAndPropertyTests.cs

@@ -78,7 +78,7 @@ namespace System.Collections.ObjectModel.Tests
         [Fact]
         public static void IEnumerableConstructorTest_Negative()
         {
-            Assert.Throws<ArgumentNullException>("collection", () => new ObservableCollection<string>((IEnumerable<string>)null));
+            AssertExtensions.Throws<ArgumentNullException>("collection", () => new ObservableCollection<string>((IEnumerable<string>)null));
         }
 
         /// <summary>
@@ -119,7 +119,8 @@ namespace System.Collections.ObjectModel.Tests
 
         [Fact]
         // skip the test on desktop as "new ObservableCollection<int>()" returns 0 length collection
-        [SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework)]
+        // skip the test on UapAot as the requires Reflection on internal framework types.
+        [SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework | TargetFrameworkMonikers.UapAot)]
         public static void DebuggerAttributeTests()
         {
             DebuggerAttributes.ValidateDebuggerDisplayReferences(new ObservableCollection<int>());
@@ -132,5 +133,36 @@ namespace System.Collections.ObjectModel.Tests
 
             public List<T> InnerList => (List<T>)base.Items;
         }
+
+        /// <summary>
+        /// Tests that ArgumentNullException is thrown when given a null IEnumerable.
+        /// </summary>
+        [Fact]
+        public static void ListConstructorTest_Negative()
+        {
+            AssertExtensions.Throws<ArgumentNullException>("list", () => new ObservableCollection<string>((List<string>)null));
+        }
+
+        [Fact]
+        public static void ListConstructorTest()
+        {
+            List<string> collection = new List<string> { "one", "two", "three" };
+            var actual = new ObservableCollection<string>(collection);
+            Assert.Equal(collection, actual);
+        }
+
+        [Fact]
+        public static void ListConstructorTest_MakesCopy()
+        {
+            List<string> collection = new List<string> { "one", "two", "three" };
+            var oc = new ObservableCollectionSubclass<string>(collection);
+            Assert.NotNull(oc.InnerList);
+            Assert.NotSame(collection, oc.InnerList);
+        }
+
+        private partial class ObservableCollectionSubclass<T> : ObservableCollection<T>
+        {
+            public ObservableCollectionSubclass(List<T> list) : base(list) { }
+        }
     }
 }

external/corefx/src/System.ObjectModel/tests/ObservableCollection/ObservableCollection_ConstructorAndPropertyTests.netstandard.cs

@@ -1,48 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using Xunit;
-
-namespace System.Collections.ObjectModel.Tests
-{
-    /// <summary>
-    /// Tests the public properties and constructor in ObservableCollection<T>.
-    /// </summary>
-    public partial class ConstructorAndPropertyTests
-    {
-        /// <summary>
-        /// Tests that ArgumentNullException is thrown when given a null IEnumerable.
-        /// </summary>
-        [Fact]
-        public static void ListConstructorTest_Negative()
-        {
-            Assert.Throws<ArgumentNullException>("list", () => new ObservableCollection<string>((List<string>)null));
-        }
-
-        [Fact]
-        public static void ListConstructorTest()
-        {
-            List<string> collection = new List<string> { "one", "two", "three" };
-            var actual = new ObservableCollection<string>(collection);
-            Assert.Equal(collection, actual);
-        }
-
-        [Fact]
-        public static void ListConstructorTest_MakesCopy()
-        {
-            List<string> collection = new List<string> { "one", "two", "three" };
-            var oc = new ObservableCollectionSubclass<string>(collection);
-            Assert.NotNull(oc.InnerList);
-            Assert.NotSame(collection, oc.InnerList);
-        }
-
-        private partial class ObservableCollectionSubclass<T> : ObservableCollection<T>
-        {
-            public ObservableCollectionSubclass(List<T> list) : base(list) { }
-        }
-    }
-}

external/corefx/src/System.ObjectModel/tests/ObservableCollection/ObservableCollection_Serialization.cs

@@ -19,6 +19,7 @@ namespace System.Collections.ObjectModel.Tests
 
         [Theory]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Serialization still WIP in UapAot: https://github.com/dotnet/corefx/issues/18942")]
         public void SerializeDeserialize_Roundtrips(ObservableCollection<int> c)
         {
             ObservableCollection<int> clone = BinaryFormatterHelpers.Clone(c);

external/corefx/src/System.ObjectModel/tests/ReadOnlyDictionary/ReadOnlyDictionaryTests.cs

@@ -211,6 +211,7 @@ namespace System.Collections.ObjectModel.Tests
         }
 
         [Fact]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Cannot do DebuggerAttribute testing on UapAot: requires internal Reflection on framework types.")]
         public static void DebuggerAttributeTests()
         {
             DebuggerAttributes.ValidateDebuggerDisplayReferences(new ReadOnlyDictionary<int, int>(new Dictionary<int, int>()));
@@ -221,6 +222,7 @@ namespace System.Collections.ObjectModel.Tests
         }
 
         [Fact]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Cannot do DebuggerAttribute testing on UapAot: requires internal Reflection on framework types.")]
         public static void DebuggerAttribute_NullDictionary_ThrowsArgumentNullException()
         {
             TargetInvocationException ex = Assert.Throws<TargetInvocationException>(() =>   DebuggerAttributes.ValidateDebuggerTypeProxyProperties(typeof(ReadOnlyDictionary<int, int>), null));
@@ -229,6 +231,7 @@ namespace System.Collections.ObjectModel.Tests
         }
         
         [Fact]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Cannot do DebuggerAttribute testing on UapAot: requires internal Reflection on framework types.")]
         public static void DebuggerAttribute_NullDictionaryKeys_ThrowsArgumentNullException()
         {
             TargetInvocationException ex = Assert.Throws<TargetInvocationException>(() => DebuggerAttributes.ValidateDebuggerTypeProxyProperties(typeof(ReadOnlyDictionary<int, int>.KeyCollection), new Type[] { typeof(int) }, null));

external/corefx/src/System.ObjectModel/tests/ReadOnlyDictionary/ReadOnlyDictionary_SerializationTests.cs

@@ -19,6 +19,7 @@ namespace System.Collections.ObjectModel.Tests
 
         [Theory]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Serialization still WIP in UapAot: https://github.com/dotnet/corefx/issues/18942")]
         public void SerializeDeserialize_Roundtrips(ReadOnlyDictionary<string, string> d)
         {
             ReadOnlyDictionary<string, string> clone = BinaryFormatterHelpers.Clone(d);

external/corefx/src/System.ObjectModel/tests/ReadOnlyObservableCollection/ReadOnlyObservableCollectionTests.cs

@@ -198,7 +198,8 @@ namespace System.Collections.ObjectModel.Tests
 
         [Fact]
         // skip the test on desktop as "new ObservableCollection<int>()" returns 0 length collection
-        [SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework)]
+        // skip the test on UapAot as the requires Reflection on internal framework types.
+        [SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework | TargetFrameworkMonikers.UapAot)]
         public static void DebuggerAttribute_Tests()
         {
             DebuggerAttributes.ValidateDebuggerDisplayReferences(new ReadOnlyObservableCollection<int>(new ObservableCollection<int>()));

external/corefx/src/System.ObjectModel/tests/ReadOnlyObservableCollection/ReadOnlyObservableCollection_SerializationTests.cs

@@ -20,6 +20,7 @@ namespace System.Collections.ObjectModel.Tests
 
         [Theory]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
+        [SkipOnTargetFramework(TargetFrameworkMonikers.UapAot, "Serialization still WIP in UapAot: https://github.com/dotnet/corefx/issues/18942")]
         public void SerializeDeserialize_Roundtrips(ReadOnlyObservableCollection<int> c)
         {
             ReadOnlyObservableCollection<int> clone = BinaryFormatterHelpers.Clone(c);

external/corefx/src/System.ObjectModel/tests/System.ObjectModel.Tests.csproj

@@ -9,6 +9,9 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'netstandard-Debug|AnyCPU'" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'netstandard-Release|AnyCPU'" />
   <ItemGroup>
+    <Compile Include="$(CommonTestPath)\System\AssertExtensions.cs">
+      <Link>Common\System\AssertExtensions.cs</Link>
+    </Compile>
     <Compile Include="$(CommonTestPath)\System\Collections\IEnumerableTest.cs">
       <Link>Common\System\CollectionsIEnumerableTest.cs</Link>
     </Compile>
@@ -27,6 +30,9 @@
     <Compile Include="$(CommonTestPath)\System\Collections\IDictionaryTest.cs">
       <Link>Common\System\CollectionsIDictionaryTest.cs</Link>
     </Compile>
+    <Compile Include="$(CommonTestPath)\System\PlatformDetection.cs">
+      <Link>Common\System\PlatformDetection.cs</Link>
+    </Compile>
     <Compile Include="ComponentModel\INotifyPropertyChangingTests.cs" />
     <Compile Include="ComponentModel\PropertyChangingEventArgsTests.cs" />
     <Compile Include="KeyedCollection\TestMethods.cs" />
@@ -46,14 +52,13 @@
     <Compile Include="KeyedCollection\TestMethods.netcoreapp.cs" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="KeyedCollection\Serialization.netstandard.cs" />
-    <Compile Include="ObservableCollection\ObservableCollection_ConstructorAndPropertyTests.netstandard.cs" />
-    <Compile Include="ObservableCollection\ObservableCollection_Serialization.netstandard.cs" />
-    <Compile Include="ReadOnlyDictionary\ReadOnlyDictionary_SerializationTests.netstandard.cs" />
-    <Compile Include="ReadOnlyObservableCollection\ReadOnlyObservableCollection_SerializationTests.netstandard.cs" />
+    <Compile Include="KeyedCollection\Serialization.cs" />
+    <Compile Include="ObservableCollection\ObservableCollection_Serialization.cs" />
+    <Compile Include="ReadOnlyDictionary\ReadOnlyDictionary_SerializationTests.cs" />
+    <Compile Include="ReadOnlyObservableCollection\ReadOnlyObservableCollection_SerializationTests.cs" />
     <Compile Include="$(CommonTestPath)\System\Runtime\Serialization\Formatters\BinaryFormatterHelpers.cs">
       <Link>Common\System\Runtime\Serialization\Formatters\BinaryFormatterHelpers.cs</Link>
     </Compile>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
-</Project>
+</Project>