Fix streaming support in client

Fixes andrewyng#103

Add support for streaming responses in the Anthropic provider.

* Handle the `stream` parameter in the `chat_completions_create` method in `aisuite/providers/anthropic_provider.py`.
* Use `handle_streaming_response` method to process streaming responses.
* Add a test case for the `stream` parameter in `tests/client/test_client.py`.

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/andrewyng/aisuite/issues/103?shareId=XXXX-XXXX-XXXX-XXXX).

aisuite/providers/anthropic_provider.py

@@ -27,14 +27,31 @@ def chat_completions_create(self, model, messages, **kwargs):
         if "max_tokens" not in kwargs:
             kwargs["max_tokens"] = DEFAULT_MAX_TOKENS
 
-        return self.normalize_response(
-            self.client.messages.create(
-                model=model, system=system_message, messages=messages, **kwargs
+        stream = kwargs.pop("stream", False)
+        if stream:
+            return self.handle_streaming_response(
+                self.client.messages.create(
+                    model=model, system=system_message, messages=messages, **kwargs
+                )
+            )
+        else:
+            return self.normalize_response(
+                self.client.messages.create(
+                    model=model, system=system_message, messages=messages, **kwargs
+                )
             )
-        )
 
     def normalize_response(self, response):
         """Normalize the response from the Anthropic API to match OpenAI's response format."""
         normalized_response = ChatCompletionResponse()
         normalized_response.choices[0].message.content = response.content[0].text
         return normalized_response
+
+    def handle_streaming_response(self, response):
+        """Handle streaming responses from the Anthropic API."""
+        normalized_response = ChatCompletionResponse()
+        content = ""
+        for chunk in response:
+            content += chunk.text
+        normalized_response.choices[0].message.content = content
+        return normalized_response

tests/client/test_client.py

@@ -139,6 +139,16 @@ def test_client_chat_completions(
         next_compl_instance = client.chat.completions
         assert compl_instance is next_compl_instance
 
+        # Test streaming response for Anthropic model
+        stream_anthropic_model = "anthropic" + ":" + "anthropic-model"
+        stream_anthropic_response = client.chat.completions.create(
+            stream_anthropic_model, messages=messages, stream=True
+        )
+        self.assertEqual(stream_anthropic_response, "Anthropic Response")
+        mock_anthropic.assert_called_with(
+            "anthropic-model", messages, stream=True
+        )
+
     def test_invalid_provider_in_client_config(self):
         # Testing an invalid provider name in the configuration
         invalid_provider_configs = {