Dictionary key by value: retarget net10.0, add prebuilt reverse map benchmarks

collections-dictionary/GetDictionaryKeyByValue/GetDictionaryKeyByValue/DictionaryHelperBenchmark.cs

@@ -13,6 +13,8 @@ public class DictionaryHelperBenchmark
 
     private readonly DictionaryHelper _dictionaryHelper = new(_benchmarkDict, "NonExistentValue");
 
+    private ReverseDictionaryLookup _reverseDictionaryLookup = null!;
+
     private static Dictionary<string, string> GetDictionary()
     {
         var benchmarkDict = new Dictionary<string, string>(100000);
@@ -26,6 +28,10 @@ private static Dictionary<string, string> GetDictionary()
         return benchmarkDict;
     }
 
+    [GlobalSetup]
+    public void Setup()
+        => _reverseDictionaryLookup = new(_benchmarkDict);
+
     [Benchmark]
     public string? UseReverseDictionary()
         => _dictionaryHelper.UseReverseDictionary();
@@ -41,4 +47,12 @@ private static Dictionary<string, string> GetDictionary()
     [Benchmark]
     public string? LoopThroughTheKeys()
         => _dictionaryHelper.LoopThroughKeys();
+
+    [Benchmark]
+    public string? UsePrebuiltReverseDictionary()
+        => _reverseDictionaryLookup.GetKeyFromReverseDictionary("NonExistentValue");
+
+    [Benchmark]
+    public string? UsePrebuiltFrozenDictionary()
+        => _reverseDictionaryLookup.GetKeyFromFrozenReverseDictionary("NonExistentValue");
 }

collections-dictionary/GetDictionaryKeyByValue/GetDictionaryKeyByValue/GetDictionaryKeyByValue.csproj

@@ -2,13 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.13.12" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.15.8" />
   </ItemGroup>
 
 </Project>

collections-dictionary/GetDictionaryKeyByValue/GetDictionaryKeyByValue/ReverseDictionaryLookup.cs

@@ -0,0 +1,36 @@
+using System.Collections.Frozen;
+
+namespace GetDictionaryKeyByValue;
+
+public class ReverseDictionaryLookup(Dictionary<string, string> dict)
+{
+    private readonly Dictionary<string, string> _reverseDict = BuildReverseDictionary(dict);
+
+    private readonly FrozenDictionary<string, string> _frozenReverseDict
+        = BuildReverseDictionary(dict).ToFrozenDictionary();
+
+    public string? GetKeyFromReverseDictionary(string value)
+    {
+        _reverseDict.TryGetValue(value, out var key);
+
+        return key;
+    }
+
+    public string? GetKeyFromFrozenReverseDictionary(string value)
+    {
+        _frozenReverseDict.TryGetValue(value, out var key);
+
+        return key;
+    }
+
+    private static Dictionary<string, string> BuildReverseDictionary(Dictionary<string, string> dict)
+    {
+        var reverseDict = new Dictionary<string, string>(dict.Count);
+        foreach (var keyValuePair in dict)
+        {
+            reverseDict.TryAdd(keyValuePair.Value, keyValuePair.Key);
+        }
+
+        return reverseDict;
+    }
+}

collections-dictionary/GetDictionaryKeyByValue/Tests/DictionaryHelperNullTest.cs

@@ -16,6 +16,8 @@ private static readonly Dictionary<string, string> _dictionary
 
     private readonly DictionaryHelper _dictionaryHelper = new(_dictionary, "NonExistentValue");
 
+    private readonly ReverseDictionaryLookup _reverseDictionaryLookup = new(_dictionary);
+
     [Fact]
     public void GivenANonExistentValue_WhenUseReverseDictionaryIsCalled_ThenReturnsNull()
     {
@@ -47,4 +49,20 @@ public void GivenANonExistentValue_WhenLoopThroughKeysIsCalled_ThenReturnsNull()
 
         Assert.Null(result);
     }
+
+    [Fact]
+    public void GivenANonExistentValue_WhenGetKeyFromReverseDictionaryIsCalled_ThenReturnsNull()
+    {
+        var result = _reverseDictionaryLookup.GetKeyFromReverseDictionary("NonExistentValue");
+
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public void GivenANonExistentValue_WhenGetKeyFromFrozenReverseDictionaryIsCalled_ThenReturnsNull()
+    {
+        var result = _reverseDictionaryLookup.GetKeyFromFrozenReverseDictionary("NonExistentValue");
+
+        Assert.Null(result);
+    }
 }

collections-dictionary/GetDictionaryKeyByValue/Tests/DictionaryHelperPositiveTest.cs

@@ -15,6 +15,8 @@ private static readonly Dictionary<string, string> _dictionary
 
     private readonly DictionaryHelper _dictionaryHelper = new(_dictionary, "value3");
 
+    private readonly ReverseDictionaryLookup _reverseDictionaryLookup = new(_dictionary);
+
     private static readonly string _expectedKey = "key3";
 
     [Fact]
@@ -48,4 +50,20 @@ public void GivenAnExistentValue_WhenLoopThroughKeysIsCalled_ThenReturnsTheDesir
 
         Assert.Equal(_expectedKey, result);
     }
+
+    [Fact]
+    public void GivenAnExistentValue_WhenGetKeyFromReverseDictionaryIsCalled_ThenReturnsTheDesiredKey()
+    {
+        var result = _reverseDictionaryLookup.GetKeyFromReverseDictionary("value3");
+
+        Assert.Equal(_expectedKey, result);
+    }
+
+    [Fact]
+    public void GivenAnExistentValue_WhenGetKeyFromFrozenReverseDictionaryIsCalled_ThenReturnsTheDesiredKey()
+    {
+        var result = _reverseDictionaryLookup.GetKeyFromFrozenReverseDictionary("value3");
+
+        Assert.Equal(_expectedKey, result);
+    }
 }

collections-dictionary/GetDictionaryKeyByValue/Tests/Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 
@@ -10,10 +10,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="coverlet.collector" Version="6.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="xunit" Version="2.5.3" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
+    <PackageReference Include="coverlet.collector" Version="10.0.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.10.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="4.0.0" />
   </ItemGroup>
 
   <ItemGroup>