Add polyfill for Dictionary<TKey, TValue>.TryAdd(...)

PolyShim.Tests/NetCore20/DictionaryTests.cs

@@ -0,0 +1,39 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using Xunit;
+
+namespace PolyShim.Tests.NetCore20;
+
+public class DictionaryTests
+{
+    [Fact]
+    public void TryAdd_Test()
+    {
+        // Arrange
+        var dictionary = new Dictionary<string, int> { ["apple"] = 1, ["banana"] = 2 };
+
+        // Act
+        var result = dictionary.TryAdd("cherry", 3);
+
+        // Assert
+        result.Should().BeTrue();
+        dictionary.Should().ContainKey("cherry");
+        dictionary["cherry"].Should().Be(3);
+        dictionary.Should().HaveCount(3);
+    }
+
+    [Fact]
+    public void TryAdd_Exists_Test()
+    {
+        // Arrange
+        var dictionary = new Dictionary<string, int> { ["apple"] = 1, ["banana"] = 2 };
+
+        // Act
+        var result = dictionary.TryAdd("apple", 99);
+
+        // Assert
+        result.Should().BeFalse();
+        dictionary["apple"].Should().Be(1);
+        dictionary.Should().HaveCount(2);
+    }
+}

PolyShim/List-Signatures.ps1

@@ -311,7 +311,7 @@ foreach ($file in $codeFiles) {
     }
 
     # Extract extension members
-    $extensionPattern = 'extension(?:<[^>]+>)?\(([^)]+)\)\s*\{'
+    $extensionPattern = 'extension(?:<[^>]+>)?\(([^)]+)\)(?:\s+where[^{]*)?\s*\{'
     $extensionMatches = [regex]::Matches($content, $extensionPattern)
 
     foreach ($match in $extensionMatches) {

PolyShim/NetCore20/Dictionary.cs

@@ -0,0 +1,25 @@
+#if (NETCOREAPP && !NETCOREAPP2_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD && !NETSTANDARD2_1_OR_GREATER)
+#nullable enable
+// ReSharper disable RedundantUsingDirective
+// ReSharper disable CheckNamespace
+// ReSharper disable InconsistentNaming
+// ReSharper disable PartialTypeWithSinglePart
+
+using System.Collections.Generic;
+
+internal static partial class PolyfillExtensions
+{
+    extension<TKey, TValue>(Dictionary<TKey, TValue> dictionary) where TKey : notnull
+    {
+        // https://learn.microsoft.com/dotnet/api/system.collections.generic.dictionary-2.tryadd
+        public bool TryAdd(TKey key, TValue value)
+        {
+            if (dictionary.ContainsKey(key))
+                return false;
+
+            dictionary.Add(key, value);
+            return true;
+        }
+    }
+}
+#endif

PolyShim/Signatures.md

@@ -1,8 +1,8 @@
 # Signatures
 
-- **Total:** 231
+- **Total:** 232
 - **Types:** 62
-- **Members:** 169
+- **Members:** 170
 
 ___
 
@@ -28,6 +28,8 @@ ___
   - [`DateTime UnixEpoch`](https://learn.microsoft.com/dotnet/api/system.datetime.unixepoch) <sup><sub>.NET Core 2.1</sub></sup>
 - `DateTimeOffset`
   - [`DateTimeOffset UnixEpoch`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset.unixepoch) <sup><sub>.NET Core 2.1</sub></sup>
+- `Dictionary<TKey, TValue>`
+  - [`bool TryAdd(TKey, TValue)`](https://learn.microsoft.com/dotnet/api/system.collections.generic.dictionary-2.tryadd) <sup><sub>.NET Core 2.0</sub></sup>
 - `DictionaryEntry`
   - [`void Deconstruct(out object, out object?)`](https://learn.microsoft.com/dotnet/api/system.collections.dictionaryentry.deconstruct) <sup><sub>.NET Core 2.0</sub></sup>
 - `DisallowNullAttribute`