Merge branch 'main' into feat/durable_task

dotnet/src/Microsoft.Agents.AI.DurableTask/CHANGELOG.md

@@ -33,9 +33,17 @@
 
 ## v1.0.0-preview.251219.1
 
+- Filter empty `AIContent` from durable agent state responses ([#4670](https://github.com/microsoft/agent-framework/pull/4670))
+
+## v1.0.0-preview.260311.1
+
+### Changed
+
 - Added TTL configuration for durable agent entities ([#2679](https://github.com/microsoft/agent-framework/pull/2679))
 - Switch to new "Run" method name ([#2843](https://github.com/microsoft/agent-framework/pull/2843))
 
+NOTE: Some of the above changes may have been part of earlier releases not mentioned in this file.
+
 ## v1.0.0-preview.251204.1
 
 - Added orchestration ID to durable agent entity state ([#2137](https://github.com/microsoft/agent-framework/pull/2137))

dotnet/src/Microsoft.Agents.AI.DurableTask/State/DurableAgentStateResponse.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System.Text.Json.Serialization;
+using Microsoft.Extensions.AI;
 
 namespace Microsoft.Agents.AI.DurableTask.State;
 
@@ -28,7 +29,10 @@ internal sealed class DurableAgentStateResponse : DurableAgentStateEntry
         {
             CorrelationId = correlationId,
             CreatedAt = response.CreatedAt ?? response.Messages.Max(m => m.CreatedAt) ?? DateTimeOffset.UtcNow,
-            Messages = response.Messages.Select(DurableAgentStateMessage.FromChatMessage).ToList(),
+            Messages = response.Messages
+                .Where(HasSerializableContent)
+                .Select(DurableAgentStateMessage.FromChatMessage)
+                .ToList(),
             Usage = DurableAgentStateUsage.FromUsage(response.Usage)
         };
     }
@@ -46,4 +50,18 @@ internal sealed class DurableAgentStateResponse : DurableAgentStateEntry
             Usage = this.Usage?.ToUsageDetails(),
         };
     }
+
+    // Checks whether a ChatMessage has any content that will produce meaningful serialized data.
+    // Known derived AIContent types (TextContent, FunctionCallContent, etc.) are always serializable.
+    // Base AIContent instances only carry RawRepresentation (which is [JsonIgnore]), Annotations, and
+    // AdditionalProperties. We keep the message if any base AIContent has annotations or additional
+    // properties set. NOTE: if AIContent gains new serializable properties in the future, this check
+    // should be updated accordingly.
+    private static bool HasSerializableContent(ChatMessage message)
+    {
+        return message.Contents.Any(c =>
+            c.GetType() != typeof(AIContent) ||
+            c.Annotations?.Count > 0 ||
+            c.AdditionalProperties?.Count > 0);
+    }
 }

dotnet/tests/Microsoft.Agents.AI.DurableTask.UnitTests/State/DurableAgentStateResponseTests.cs

@@ -0,0 +1,142 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.DurableTask.State;
+using Microsoft.Extensions.AI;
+
+namespace Microsoft.Agents.AI.DurableTask.Tests.Unit.State;
+
+public sealed class DurableAgentStateResponseTests
+{
+    [Fact]
+    public void FromResponseDropsMessagesContainingOnlyOpaqueContent()
+    {
+        // Arrange: one message with real text, one with only opaque AIContent
+        ChatMessage usefulMessage = new(ChatRole.Assistant, "Hello, world!")
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+        ChatMessage opaqueOnlyMessage = new(ChatRole.Assistant, [
+            new AIContent
+            {
+                RawRepresentation = new { kind = "sessionEvent", sessionId = "s123" }
+            }])
+        {
+            CreatedAt = DateTimeOffset.UtcNow.AddSeconds(1)
+        };
+
+        AgentResponse response = new(new List<ChatMessage> { usefulMessage, opaqueOnlyMessage })
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+
+        // Act
+        DurableAgentStateResponse durableResponse = DurableAgentStateResponse.FromResponse("corr-123", response);
+
+        // Assert: only the useful message survives
+        DurableAgentStateMessage durableMessage = Assert.Single(durableResponse.Messages);
+        Assert.Equal(ChatRole.Assistant.Value, durableMessage.Role);
+
+        // Round-trip to verify the content is correct
+        AgentResponse convertedResponse = durableResponse.ToResponse();
+        ChatMessage convertedMessage = Assert.Single(convertedResponse.Messages);
+        TextContent textContent = Assert.IsType<TextContent>(Assert.Single(convertedMessage.Contents));
+        Assert.Equal("Hello, world!", textContent.Text);
+    }
+
+    [Fact]
+    public void FromResponseKeepsMessagesWithMixedContent()
+    {
+        // Arrange: one message with both real text and opaque AIContent
+        ChatMessage mixedMessage = new(ChatRole.Assistant, [
+            new TextContent("Some useful text"),
+            new AIContent { RawRepresentation = new { kind = "metadata" } }])
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+
+        AgentResponse response = new(new List<ChatMessage> { mixedMessage })
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+
+        // Act
+        DurableAgentStateResponse durableResponse = DurableAgentStateResponse.FromResponse("corr-456", response);
+
+        // Assert: the message is kept because it contains at least one serializable content
+        DurableAgentStateMessage durableMessage = Assert.Single(durableResponse.Messages);
+        Assert.Equal(ChatRole.Assistant.Value, durableMessage.Role);
+    }
+
+    [Fact]
+    public void FromResponseDropsAllMessagesWhenAllAreOpaque()
+    {
+        // Arrange: all messages contain only opaque AIContent
+        ChatMessage opaque1 = new(ChatRole.Assistant, [
+            new AIContent { RawRepresentation = new { kind = "event1" } }])
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+        ChatMessage opaque2 = new(ChatRole.Assistant, [
+            new AIContent { RawRepresentation = new { kind = "event2" } }])
+        {
+            CreatedAt = DateTimeOffset.UtcNow.AddSeconds(1)
+        };
+
+        AgentResponse response = new(new List<ChatMessage> { opaque1, opaque2 })
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+
+        // Act
+        DurableAgentStateResponse durableResponse = DurableAgentStateResponse.FromResponse("corr-789", response);
+
+        // Assert: no messages stored
+        Assert.Empty(durableResponse.Messages);
+    }
+
+    [Fact]
+    public void FromResponseKeepsBaseAIContentWithAnnotations()
+    {
+        // Arrange: base AIContent with annotations should be kept
+        AIContent contentWithAnnotations = new()
+        {
+            RawRepresentation = new { kind = "event" },
+            Annotations = [new AIAnnotation() { AdditionalProperties = new() { ["cite"] = "ref-1" } }]
+        };
+        ChatMessage message = new(ChatRole.Assistant, [contentWithAnnotations])
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+
+        AgentResponse response = new([message]) { CreatedAt = DateTimeOffset.UtcNow };
+
+        // Act
+        DurableAgentStateResponse durableResponse = DurableAgentStateResponse.FromResponse("corr-ann", response);
+
+        // Assert: message is kept because the AIContent has annotations
+        Assert.Single(durableResponse.Messages);
+    }
+
+    [Fact]
+    public void FromResponseKeepsBaseAIContentWithAdditionalProperties()
+    {
+        // Arrange: base AIContent with additional properties should be kept
+        AIContent contentWithProps = new()
+        {
+            RawRepresentation = new { kind = "event" },
+            AdditionalProperties = new() { ["custom_key"] = "custom_value" }
+        };
+        ChatMessage message = new(ChatRole.Assistant, [contentWithProps])
+        {
+            CreatedAt = DateTimeOffset.UtcNow
+        };
+
+        AgentResponse response = new([message]) { CreatedAt = DateTimeOffset.UtcNow };
+
+        // Act
+        DurableAgentStateResponse durableResponse = DurableAgentStateResponse.FromResponse("corr-props", response);
+
+        // Assert: message is kept because the AIContent has additional properties
+        Assert.Single(durableResponse.Messages);
+    }
+}