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Add FrozenDictionary.Create (#114192)
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+107
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4 files changed

+107
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‎src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs‎

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@@ -8,6 +8,8 @@ namespace System.Collections.Frozen
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{
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public static partial class FrozenDictionary
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{
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public static System.Collections.Frozen.FrozenDictionary<TKey, TValue> Create<TKey, TValue>(params System.ReadOnlySpan<System.Collections.Generic.KeyValuePair<TKey, TValue>> source) where TKey : notnull { throw null; }
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public static System.Collections.Frozen.FrozenDictionary<TKey, TValue> Create<TKey, TValue>(System.Collections.Generic.IEqualityComparer<TKey>? comparer, params System.ReadOnlySpan<System.Collections.Generic.KeyValuePair<TKey, TValue>> source) where TKey : notnull { throw null; }
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public static System.Collections.Frozen.FrozenDictionary<TKey, TValue> ToFrozenDictionary<TKey, TValue>(this System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TValue>> source, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) where TKey : notnull { throw null; }
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public static System.Collections.Frozen.FrozenDictionary<TKey, TSource> ToFrozenDictionary<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) where TKey : notnull { throw null; }
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public static System.Collections.Frozen.FrozenDictionary<TKey, TElement> ToFrozenDictionary<TSource, TKey, TElement>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, System.Func<TSource, TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) where TKey : notnull { throw null; }

‎src/libraries/System.Collections.Immutable/src/CompatibilitySuppressions.xml‎

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@@ -0,0 +1,22 @@
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<?xml version="1.0" encoding="utf-8"?>
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<!-- https://learn.microsoft.com/dotnet/fundamentals/package-validation/diagnostic-ids -->
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<Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
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<Suppression>
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<DiagnosticId>CP0016</DiagnosticId>
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<Target>T:System.Collections.Frozen.FrozenDictionary`2:[T:System.Runtime.CompilerServices.CollectionBuilderAttribute]</Target>
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<Left>ref/net10.0/System.Collections.Immutable.dll</Left>
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<Right>lib/net10.0/System.Collections.Immutable.dll</Right>
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</Suppression>
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<Suppression>
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<DiagnosticId>CP0016</DiagnosticId>
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<Target>T:System.Collections.Frozen.FrozenDictionary`2:[T:System.Runtime.CompilerServices.CollectionBuilderAttribute]</Target>
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<Left>ref/net8.0/System.Collections.Immutable.dll</Left>
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<Right>lib/net8.0/System.Collections.Immutable.dll</Right>
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</Suppression>
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<Suppression>
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<DiagnosticId>CP0016</DiagnosticId>
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<Target>T:System.Collections.Frozen.FrozenDictionary`2:[T:System.Runtime.CompilerServices.CollectionBuilderAttribute]</Target>
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<Left>ref/net9.0/System.Collections.Immutable.dll</Left>
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<Right>lib/net9.0/System.Collections.Immutable.dll</Right>
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</Suppression>
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</Suppressions>

‎src/libraries/System.Collections.Immutable/src/System/Collections/Frozen/FrozenDictionary.cs‎

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@@ -16,6 +16,50 @@ namespace System.Collections.Frozen
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/// </summary>
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public static class FrozenDictionary
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{
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/// <summary>Creates a <see cref="FrozenDictionary{TKey, TValue}"/> with the specified key/value pairs.</summary>
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/// <param name="source">The key/value pairs to use to populate the dictionary.</param>
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/// <typeparam name="TKey">The type of the keys in the dictionary.</typeparam>
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/// <typeparam name="TValue">The type of the values in the dictionary.</typeparam>
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/// <remarks>
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/// If the same key appears multiple times in the input, the latter one in the sequence takes precedence. This differs from
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/// <see cref="M:System.Linq.Enumerable.ToDictionary"/>, with which multiple duplicate keys will result in an exception.
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/// </remarks>
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/// <returns>A <see cref="FrozenDictionary{TKey, TValue}"/> that contains the specified keys and values.</returns>
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public static FrozenDictionary<TKey, TValue> Create<TKey, TValue>(params ReadOnlySpan<KeyValuePair<TKey, TValue>> source)
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where TKey : notnull =>
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Create(null, source);
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/// <summary>Creates a <see cref="FrozenDictionary{TKey, TValue}"/> with the specified key/value pairs.</summary>
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/// <param name="source">The key/value pairs to use to populate the dictionary.</param>
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/// <param name="comparer">The comparer implementation to use to compare keys for equality. If <see langword="null"/>, <see cref="EqualityComparer{TKey}.Default"/> is used.</param>
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/// <typeparam name="TKey">The type of the keys in the dictionary.</typeparam>
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/// <typeparam name="TValue">The type of the values in the dictionary.</typeparam>
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/// <remarks>
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/// If the same key appears multiple times in the input, the latter one in the sequence takes precedence. This differs from
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/// <see cref="M:System.Linq.Enumerable.ToDictionary"/>, with which multiple duplicate keys will result in an exception.
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/// </remarks>
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/// <returns>A <see cref="FrozenDictionary{TKey, TValue}"/> that contains the specified keys and values.</returns>
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public static FrozenDictionary<TKey, TValue> Create<TKey, TValue>(IEqualityComparer<TKey>? comparer, params ReadOnlySpan<KeyValuePair<TKey, TValue>> source)
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where TKey : notnull
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{
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comparer ??= EqualityComparer<TKey>.Default;
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if (source.IsEmpty)
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{
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return ReferenceEquals(comparer, FrozenDictionary<TKey, TValue>.Empty.Comparer) ?
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FrozenDictionary<TKey, TValue>.Empty :
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new EmptyFrozenDictionary<TKey, TValue>(comparer);
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}
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Dictionary<TKey, TValue> d = new(source.Length, comparer);
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foreach (KeyValuePair<TKey, TValue> pair in source)
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{
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d[pair.Key] = pair.Value;
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}
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return CreateFromDictionary(d);
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}
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/// <summary>Creates a <see cref="FrozenDictionary{TKey, TValue}"/> with the specified key/value pairs.</summary>
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/// <param name="source">The key/value pairs to use to populate the dictionary.</param>
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/// <param name="comparer">The comparer implementation to use to compare keys for equality. If null, <see cref="EqualityComparer{TKey}.Default"/> is used.</param>
@@ -259,6 +303,7 @@ private static FrozenDictionary<TKey, TValue> CreateFromDictionary<TKey, TValue>
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/// the remainder of the life of the application. <see cref="FrozenDictionary{TKey, TValue}"/> should only be
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/// initialized with trusted keys, as the details of the keys impacts construction time.
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/// </remarks>
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[CollectionBuilder(typeof(FrozenDictionary), nameof(FrozenDictionary.Create))]
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[DebuggerTypeProxy(typeof(ImmutableDictionaryDebuggerProxy<,>))]
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[DebuggerDisplay("Count = {Count}")]
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public abstract partial class FrozenDictionary<TKey, TValue> : IDictionary<TKey, TValue>, IReadOnlyDictionary<TKey, TValue>, IDictionary

‎src/libraries/System.Collections.Immutable/tests/Frozen/FrozenDictionaryTests.cs‎

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@@ -85,7 +85,7 @@ public void NullSource_ThrowsException()
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}
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[Fact]
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public void EmptySource_ProducedFrozenDictionaryEmpty()
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public void EmptyEnumerableSource_ProducedFrozenDictionaryEmpty()
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{
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IEnumerable<KeyValuePair<TKey, TValue>>[] sources = new[]
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{
@@ -118,6 +118,23 @@ public void EmptySource_ProducedFrozenDictionaryEmpty()
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}
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}
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[Fact]
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public void EmptySpanSource_ProducedFrozenDictionaryEmpty()
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{
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ReadOnlySpan<KeyValuePair<TKey, TValue>> source = default;
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Assert.Same(FrozenDictionary<TKey, TValue>.Empty, FrozenDictionary.Create(source));
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foreach (IEqualityComparer<TKey> comparer in new IEqualityComparer<TKey>[] { null, EqualityComparer<TKey>.Default })
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{
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Assert.Same(FrozenDictionary<TKey, TValue>.Empty, FrozenDictionary.Create(comparer, source));
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}
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Assert.NotSame(FrozenDictionary<TKey, TValue>.Empty, FrozenDictionary.Create(NonDefaultEqualityComparer<TKey>.Instance, source));
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Assert.Equal(0, FrozenDictionary.Create(NonDefaultEqualityComparer<TKey>.Instance, source).Count);
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}
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[Fact]
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public void EmptyFrozenDictionary_Idempotent()
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{
@@ -202,23 +219,28 @@ public void ToFrozenDictionary_KeySelectorAndValueSelector_ResultsAreUsed()
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}
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public static IEnumerable<object[]> LookupItems_AllItemsFoundAsExpected_MemberData() =>
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from useToFrozenDictionary in new[] { false, true }
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from size in new[] { 0, 1, 2, 10, 99 }
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from comparer in new IEqualityComparer<TKey>[] { null, EqualityComparer<TKey>.Default, NonDefaultEqualityComparer<TKey>.Instance }
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from specifySameComparer in new[] { false, true }
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select new object[] { size, comparer, specifySameComparer };
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select new object[] { useToFrozenDictionary, size, comparer, specifySameComparer };
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[Theory]
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[MemberData(nameof(LookupItems_AllItemsFoundAsExpected_MemberData))]
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public void LookupItems_AllItemsFoundAsExpected(int size, IEqualityComparer<TKey> comparer, bool specifySameComparer)
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public void LookupItems_AllItemsFoundAsExpected(bool useToFrozenDictionary, int size, IEqualityComparer<TKey> comparer, bool specifySameComparer)
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{
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Dictionary<TKey, TValue> original =
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GenerateUniqueKeyValuePairs(size)
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.ToDictionary(p => p.Key, p => p.Value, comparer);
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KeyValuePair<TKey, TValue>[] originalPairs = original.ToArray();
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FrozenDictionary<TKey, TValue> frozen = specifySameComparer ?
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original.ToFrozenDictionary(comparer) :
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original.ToFrozenDictionary();
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FrozenDictionary<TKey, TValue> frozen = (useToFrozenDictionary, specifySameComparer) switch
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{
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(true, true) => original.ToFrozenDictionary(comparer),
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(true, false) => original.ToFrozenDictionary(),
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(false, true) => FrozenDictionary.Create(comparer, originalPairs),
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(false, false) => FrozenDictionary.Create(originalPairs),
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};
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// Make sure creating the frozen dictionary didn't alter the original
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Assert.Equal(originalPairs.Length, original.Count);
@@ -283,8 +305,10 @@ public void EqualButPossiblyDifferentKeys_Found(bool fromDictionary)
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}
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}
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[Fact]
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public void MultipleValuesSameKey_LastInSourceWins()
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[Theory]
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[InlineData(false)]
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[InlineData(true)]
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public void MultipleValuesSameKey_LastInSourceWins(bool useToFrozenDictionary)
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{
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TKey[] keys = GenerateUniqueKeyValuePairs(2).Select(pair => pair.Key).ToArray();
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TValue[] values = Enumerable.Range(0, 10).Select(CreateTValue).ToArray();
@@ -301,7 +325,9 @@ from value in values
301325
source = source.Reverse();
302326
}
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304-
FrozenDictionary<TKey, TValue> frozen = source.ToFrozenDictionary(GetKeyIEqualityComparer());
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FrozenDictionary<TKey, TValue> frozen = useToFrozenDictionary ?
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source.ToFrozenDictionary(GetKeyIEqualityComparer()) :
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FrozenDictionary.Create(GetKeyIEqualityComparer(), source.ToArray());
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Assert.Equal(values[reverse ? 0 : values.Length - 1], frozen[keys[0]]);
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Assert.Equal(values[reverse ? 0 : values.Length - 1], frozen[keys[1]]);
@@ -387,7 +413,9 @@ public void ContainsKey_WithNonAscii(int percentageWithNonAscii)
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expected.Add(value, value);
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}
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FrozenDictionary<string, string> actual = expected.ToFrozenDictionary(GetKeyIEqualityComparer());
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FrozenDictionary<string, string> actual = percentageWithNonAscii % 2 == 0 ?
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expected.ToFrozenDictionary(GetKeyIEqualityComparer()) :
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FrozenDictionary.Create(GetKeyIEqualityComparer(), expected.ToArray());
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392420
Assert.All(expected, kvp => actual.ContainsKey(kvp.Key));
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}

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