feat: yield events for streaming including custom message complete event

tests/AnthropicClient.Tests/EndToEnd/AnthropicApiClientTests.cs

@@ -0,0 +1,61 @@
+namespace AnthropicClient.Tests.EndToEnd;
+
+public class ClientTests(
+  HttpClientFixture httpClientFixture,
+  ConfigurationFixture configFixture
+) : EndToEndTest(httpClientFixture, configFixture)
+{
+  [Fact]
+  public async Task CreateChatMessage_WhenCalled_ItShouldReturnChatResponse()
+  {
+    var request = new ChatMessageRequest(
+      model: AnthropicModels.Claude3Haiku,
+      messages: [new(MessageRole.User, [new TextContent("Hello!")])]
+    );
+
+    var result = await _client.CreateChatMessageAsync(request);
+
+    result.IsSuccess.Should().BeTrue();
+    result.Value.Should().BeOfType<ChatResponse>();
+  }
+
+  [Fact]
+  public async Task CreateChatMessage_WhenCalledWithStreamRequest_ItShouldReturnEvents()
+  {
+    var request = new StreamChatMessageRequest(
+      model: AnthropicModels.Claude3Haiku,
+      messages: [new(MessageRole.User, [new TextContent("Hello!")])]
+    );
+
+    var response = _client.CreateChatMessageAsync(request);
+    
+    var events = new List<AnthropicEvent>();
+
+    await foreach (var e in response)
+    {
+      events.Add(e);
+    }
+
+    events.Should().NotBeEmpty();
+  }
+
+  [Fact]
+  public async Task CreateChatMessage_WhenCalledWithStreamRequest_ItShouldYieldAMessageCompleteEvent()
+  {
+    var request = new StreamChatMessageRequest(
+      model: AnthropicModels.Claude3Haiku,
+      messages: [new(MessageRole.User, [new TextContent("Hello!")])]
+    );
+
+    var response = _client.CreateChatMessageAsync(request);
+  
+    await foreach (var e in response)
+    {
+      if (e.Data is MessageCompleteEventData messageCompleteData)
+      {
+        messageCompleteData.Message.Should().NotBeNull();
+        break;
+      }
+    }
+  }
+}