Increase coverage

Author: Youssef1313

dotnet/tests/Microsoft.Agents.AI.Abstractions.UnitTests/AIContextProviderTests.cs

@@ -34,6 +34,22 @@ public void InvokingContext_Constructor_ThrowsForNullMessages()
         Assert.Throws<ArgumentNullException>(() => new AIContextProvider.InvokingContext(null!));
     }
 
+    [Fact]
+    public void InvokingContext_Constructor_DoesNotThrowForEmptyMessages()
+    {
+        var context = new AIContextProvider.InvokingContext([]);
+        Assert.Empty(context.RequestMessages);
+    }
+
+    [Fact]
+    public void InvokingContext_Constructor_DoesNotThrowForSingleMessages()
+    {
+        var expected = new ChatMessage(ChatRole.User, "Message content");
+        var context = new AIContextProvider.InvokingContext([expected]);
+        var actual = Assert.Single(context.RequestMessages);
+        Assert.Equal(expected, actual);
+    }
+
     [Fact]
     public void InvokedContext_Constructor_ThrowsForNullMessages()
     {

dotnet/tests/Microsoft.Agents.AI.Abstractions.UnitTests/AgentRunOptionsTests.cs

@@ -39,6 +39,28 @@ public void CloningConstructorCopiesProperties()
         Assert.Equal(42, clone.AdditionalProperties["key2"]);
     }
 
+    [Fact]
+    public void CloningConstructorWithNullProperties()
+    {
+        // Arrange
+        var options = new AgentRunOptions
+        {
+            ContinuationToken = new object(),
+            AllowBackgroundResponses = true,
+            AdditionalProperties = null,
+        };
+
+        // Act
+        var clone = new AgentRunOptions(options);
+
+        // Assert
+        Assert.NotNull(clone);
+        Assert.Same(options.ContinuationToken, clone.ContinuationToken);
+        Assert.Equal(options.AllowBackgroundResponses, clone.AllowBackgroundResponses);
+        Assert.Null(clone.AdditionalProperties);
+        Assert.Null(options.AdditionalProperties);
+    }
+
     [Fact]
     public void CloningConstructorThrowsIfNull() =>
         // Act & Assert