fix: correct problems with ollama and aider (#596)

It has a pair of problems:
- always need to check that the model contains some value
- only send chunks that contain data, and do not send double newlines
as they get considered as a different chunk

Closes: #586

Author: yrobla

src/codegate/providers/ollama/completion_handler.py

@@ -1,3 +1,4 @@
+import json
 from typing import AsyncIterator, Optional, Union
 
 import structlog
@@ -11,18 +12,21 @@
 
 
 async def ollama_stream_generator(
-    stream: AsyncIterator[ChatResponse],
+    stream: AsyncIterator[ChatResponse]
 ) -> AsyncIterator[str]:
     """OpenAI-style SSE format"""
     try:
         async for chunk in stream:
-            print(chunk)
             try:
-                yield f"{chunk.model_dump_json()}\n\n"
+                content = chunk.model_dump_json()
+                if content:
+                    yield f"{chunk.model_dump_json()}\n"
             except Exception as e:
-                yield f"{str(e)}\n\n"
+                if str(e):
+                    yield f"{str(e)}\n"
     except Exception as e:
-        yield f"{str(e)}\n\n"
+        if str(e):
+            yield f"{str(e)}\n"
 
 
 class OllamaShim(BaseCompletionHandler):
@@ -39,17 +43,17 @@ async def execute_completion(
     ) -> Union[ChatResponse, GenerateResponse]:
         """Stream response directly from Ollama API."""
         if is_fim_request:
-            prompt = request["messages"][0]["content"]
+            prompt = request["messages"][0].get("content", "")
             response = await self.client.generate(
-                model=request["model"], prompt=prompt, stream=stream, options=request["options"]
+                model=request["model"], prompt=prompt, stream=stream, options=request["options"]  # type: ignore
             )
         else:
             response = await self.client.chat(
                 model=request["model"],
                 messages=request["messages"],
-                stream=stream,
-                options=request["options"],
-            )
+                stream=stream,  # type: ignore
+                options=request["options"],  # type: ignore
+            )  # type: ignore
         return response
 
     def _create_streaming_response(self, stream: AsyncIterator[ChatResponse]) -> StreamingResponse:

src/codegate/providers/ollama/provider.py

@@ -58,6 +58,9 @@ async def show_model(request: Request):
             https://github.com/ollama/ollama/blob/main/docs/api.md#show-model-information
             """
             body = await request.body()
+            body_json = json.loads(body)
+            if "name" not in body_json:
+                raise HTTPException(status_code=400, detail="model is required in the request body")
             async with httpx.AsyncClient() as client:
                 response = await client.post(
                     f"{self.base_url}/api/show",