fix: address embedder review feedback

src/companion/rag/embedder.py

@@ -5,10 +5,18 @@ import httpx
 
 
 class OllamaEmbedder:
-    def __init__(self, base_url: str, model: str, batch_size: int):
+    def __init__(
+        self,
+        base_url: str,
+        model: str,
+        batch_size: int,
+        timeout: float = 300.0,
+    ):
         self.base_url = base_url.rstrip("/")
         self.model = model
         self.batch_size = batch_size
+        self.timeout = timeout
+        self._client = httpx.Client(timeout=timeout)
 
     def embed(
         self, texts: List[str], retries: int = 3, backoff: float = 1.0
@@ -22,23 +30,41 @@ class OllamaEmbedder:
 
             for attempt in range(retries):
                 try:
-                    with httpx.Client(timeout=300.0) as client:
-                        response = client.post(
+                    response = self._client.post(
                         url,
                         json={"model": self.model, "input": batch},
                     )
                     response.raise_for_status()
                     data = response.json()
                     embeddings = data["embeddings"]
+
+                    # Validate response count matches batch count
+                    if len(embeddings) != len(batch):
+                        raise ValueError(
+                            f"Ollama returned {len(embeddings)} embeddings for {len(batch)} texts"
+                        )
+
                     all_embeddings.extend(embeddings)
                     break
-                except Exception as exc:
+                except (httpx.HTTPError, httpx.RequestError) as exc:
                     last_exception = exc
                     if attempt < retries - 1:
                         time.sleep(backoff * (2**attempt))
             else:
                 raise RuntimeError(
-                    f"Failed to embed batch after {retries} retries"
+                    f"Failed to embed batch after {retries} retries. "
+                    f"Last error: {last_exception}"
                 ) from last_exception
 
         return all_embeddings
+
+    def close(self) -> None:
+        """Close the HTTP client."""
+        self._client.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+        return False

tests/test_embedder.py

@@ -19,3 +19,50 @@ def test_embed_batch():
     assert result[0][0] == 0.1
     assert result[1][0] == 0.2
     assert route.called
+
+
+@respx.mock
+def test_embed_multi_batch():
+    """Test that texts are split into multiple batches and results are concatenated."""
+    route = respx.post("http://localhost:11434/api/embed").mock(
+        side_effect=[
+            Response(200, json={"embeddings": [[0.1] * 1024]}),
+            Response(200, json={"embeddings": [[0.2] * 1024]}),
+        ]
+    )
+    embedder = OllamaEmbedder(
+        base_url="http://localhost:11434", model="mxbai-embed-large", batch_size=1
+    )
+    result = embedder.embed(["hello", "world"])
+    assert len(result) == 2
+    assert result[0][0] == 0.1
+    assert result[1][0] == 0.2
+    assert route.call_count == 2
+
+
+@respx.mock
+def test_embed_retry_exhaustion():
+    """Test that RuntimeError is raised after all retries fail."""
+    route = respx.post("http://localhost:11434/api/embed").mock(
+        return_value=Response(500, text="Internal Server Error")
+    )
+    embedder = OllamaEmbedder(
+        base_url="http://localhost:11434", model="mxbai-embed-large", batch_size=2
+    )
+    with pytest.raises(RuntimeError, match="Failed to embed batch after 3 retries"):
+        embedder.embed(["hello world"], retries=3, backoff=0.01)
+    assert route.call_count == 3
+
+
+@respx.mock
+def test_embed_count_mismatch():
+    """Test that ValueError is raised when Ollama returns fewer embeddings than texts."""
+    route = respx.post("http://localhost:11434/api/embed").mock(
+        return_value=Response(200, json={"embeddings": [[0.1] * 1024]})
+    )
+    embedder = OllamaEmbedder(
+        base_url="http://localhost:11434", model="mxbai-embed-large", batch_size=2
+    )
+    with pytest.raises(ValueError, match="returned 1 embeddings for 2 texts"):
+        embedder.embed(["hello world", "goodbye world"])
+    assert route.called