Fix dictionary creation

src/Common/DiagnosticEditProperties.cs

@@ -40,11 +40,10 @@ internal enum EditType
     /// <returns>The current object as an immutable dictionary.</returns>
     public ImmutableDictionary<string, string?> ToImmutableDictionary()
     {
-        return new Dictionary<string, string?>(StringComparer.Ordinal)
-        {
-            { EditTypeKey, TypeOfEdit.ToString() },
-            { EditPositionKey, EditPosition.ToString(CultureInfo.InvariantCulture) },
-        }.ToImmutableDictionary();
+        var builder = ImmutableDictionary.CreateBuilder<string, string?>(StringComparer.Ordinal);
+        builder.Add(EditTypeKey, TypeOfEdit.ToString());
+        builder.Add(EditPositionKey, EditPosition.ToString(CultureInfo.InvariantCulture));
+        return builder.ToImmutable();
     }
 
     /// <summary>

tests/Moq.Analyzers.Benchmarks/DiagnosticEditPropertiesBenchmarks.cs

@@ -0,0 +1,28 @@
+using System.Collections.Immutable;
+using System.Globalization;
+
+namespace Moq.Analyzers.Benchmarks;
+
+[InProcess]
+[MemoryDiagnoser]
+public class DiagnosticEditPropertiesBenchmarks
+{
+    [Benchmark(Baseline = true)]
+    public ImmutableDictionary<string, string?> UsingBuilder()
+    {
+        var builder = ImmutableDictionary.CreateBuilder<string, string?>(StringComparer.Ordinal);
+        builder.Add("Type", "Insert");
+        builder.Add("Position", 1.ToString(CultureInfo.InvariantCulture));
+        return builder.ToImmutable();
+    }
+
+    [Benchmark]
+    public ImmutableDictionary<string, string?> UsingDictionary()
+    {
+        return new Dictionary<string, string?>(StringComparer.Ordinal)
+        {
+            { "Type", "Insert" },
+            { "Position", 1.ToString(CultureInfo.InvariantCulture) },
+        }.ToImmutableDictionary();
+    }
+}