Top-level client options bug fix and test

.dotnet/CHANGELOG.md

@@ -11,6 +11,8 @@
 
 ### Bugs Fixed
 
+- Fixed a newly introduced bug ([#185](https://github.com/openai/openai-dotnet/pull/185)) where providing `OpenAIClientOptions` to a top-level `OpenAIClient` did not carry over to scenario clients (e.g. `ChatClient`) created via that top-level client
+
 ### Other Changes
 
 - Removed the version path parameter "v1" from the default endpoint URL. (commit_hash)

.dotnet/src/Custom/OpenAIClient.cs

@@ -98,6 +98,7 @@ public OpenAIClient(ApiKeyCredential credential, OpenAIClientOptions options)
 
         _pipeline = OpenAIClient.CreatePipeline(credential, options);
         _endpoint = OpenAIClient.GetEndpoint(options);
+        _options = options;
     }
 
     // CUSTOM: Added protected internal constructor that takes a ClientPipeline.

.dotnet/tests/Chat/ChatSmokeTests.cs

@@ -585,4 +585,29 @@ public void SerializeMessagesWithNullProperties()
         FunctionChatMessage deserializedMessage = ModelReaderWriter.Read<FunctionChatMessage>(serializedMessage);
 #pragma warning restore
     }
+
+    [Test]
+    public void TopLevelClientOptionsPersistence()
+    {
+        MockPipelineTransport mockTransport = new(BinaryData.FromString("{}"), BinaryData.FromString("{}"));
+        OpenAIClientOptions options = new()
+        {
+            Transport = mockTransport,
+            Endpoint = new Uri("https://api.openai.com/expected/test/endpoint"),
+        };
+        Uri observedEndpoint = null;
+        options.AddPolicy(new TestPipelinePolicy(message =>
+        {
+            observedEndpoint = message?.Request?.Uri;
+            Console.WriteLine($"foo: {message.Request.Uri.AbsoluteUri}");
+        }),
+        PipelinePosition.PerCall);
+
+        OpenAIClient topLevelClient = new(new("mock-credential"), options);
+        ChatClient firstClient = topLevelClient.GetChatClient("mock-model");
+        ClientResult first = firstClient.CompleteChat("Hello, world");
+
+        Assert.That(observedEndpoint, Is.Not.Null);
+        Assert.That(observedEndpoint.AbsoluteUri, Does.Contain("expected/test/endpoint"));
+    }
 }