.NET: Durable extension: initial src and unit tests (#1900)

dotnet/tests/Microsoft.Agents.AI.DurableTask.UnitTests/DurableAgentThreadTests.cs

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text.Json;
+
+namespace Microsoft.Agents.AI.DurableTask.UnitTests;
+
+public sealed class DurableAgentThreadTests
+{
+    [Fact]
+    public void BuiltInSerialization()
+    {
+        AgentSessionId sessionId = AgentSessionId.WithRandomKey("test-agent");
+        AgentThread thread = new DurableAgentThread(sessionId);
+
+        JsonElement serializedThread = thread.Serialize();
+
+        // Expected format: "{\"sessionId\":\"@dafx-test-agent@<random-key>\"}"
+        string expectedSerializedThread = $"{{\"sessionId\":\"@dafx-{sessionId.Name}@{sessionId.Key}\"}}";
+        Assert.Equal(expectedSerializedThread, serializedThread.ToString());
+
+        DurableAgentThread deserializedThread = DurableAgentThread.Deserialize(serializedThread);
+        Assert.Equal(sessionId, deserializedThread.SessionId);
+    }
+
+    [Fact]
+    public void STJSerialization()
+    {
+        AgentSessionId sessionId = AgentSessionId.WithRandomKey("test-agent");
+        AgentThread thread = new DurableAgentThread(sessionId);
+
+        // Need to specify the type explicitly because STJ, unlike other serializers,
+        // does serialization based on the static type of the object, not the runtime type.
+        string serializedThread = JsonSerializer.Serialize(thread, typeof(DurableAgentThread));
+
+        // Expected format: "{\"sessionId\":\"@dafx-test-agent@<random-key>\"}"
+        string expectedSerializedThread = $"{{\"sessionId\":\"@dafx-{sessionId.Name}@{sessionId.Key}\"}}";
+        Assert.Equal(expectedSerializedThread, serializedThread);
+
+        DurableAgentThread? deserializedThread = JsonSerializer.Deserialize<DurableAgentThread>(serializedThread);
+        Assert.NotNull(deserializedThread);
+        Assert.Equal(sessionId, deserializedThread.SessionId);
+    }
+}