Correctly convert dictionary keys to string

Fluid.Tests/DictionaryDictionaryFluidIndexableTests.cs

@@ -0,0 +1,51 @@
+using Fluid.Values;
+using System.Collections.Generic;
+using System.Linq;
+using Xunit;
+
+namespace Fluid.Tests;
+
+public class DictionaryDictionaryFluidIndexableTests
+{
+    [Fact]
+    public void CountShouldHaveTheSameLengthAsKeysWhenKeyInLong()
+    {
+        var items = new Dictionary<long, string>()
+        {
+            {1, "a"},
+            {2, "b"},
+            {3, "c"},
+            {4, "d"},
+            {5, "e"},
+        };
+
+        var value = FluidValue.Create(items, new TemplateOptions());
+
+        var castedValue = value.ToObjectValue() as IFluidIndexable;
+
+        Assert.NotNull(castedValue);
+
+        Assert.Equal(items.Count, castedValue.Keys.Count());
+    }
+
+    [Fact]
+    public void CountShouldHaveTheSameLengthAsKeysWhenKeyInString()
+    {
+        var items = new Dictionary<string, string>()
+        {
+            {"1", "a"},
+            {"2", "b"},
+            {"3", "c"},
+            {"4", "d"},
+            {"5", "e"},
+        };
+
+        var value = FluidValue.Create(items, new TemplateOptions());
+
+        var castedValue = value.ToObjectValue() as IFluidIndexable;
+
+        Assert.NotNull(castedValue);
+
+        Assert.Equal(items.Count, castedValue.Keys.Count());
+    }
+}

Fluid/Values/DictionaryDictionaryFluidIndexable.cs

@@ -23,7 +23,11 @@ public IEnumerable<string> Keys
                 foreach (var key in _dictionary.Keys)
                 {
                     // Only handle string keys since this is what TryGetValue returns
-                    if (key is string)
+                    if (key is string str)
+                    {
+                        yield return str;
+                    }
+                    else
                     {
                         yield return key.ToString();
                     }