refactor(rag_engine): Result API + NilRAGState (_init_vector_store, _validate_collection_dim, _get_state)

src/rag_engine.py

@@ -9,6 +9,7 @@ from typing import List, Dict, Any, Optional
 from src import ai_client
 from src import models
 from src import mcp_client
+from src.result_types import ErrorInfo, ErrorKind, NilRAGState, Result
 
 from src.file_cache import ASTParser
 
@@ -95,7 +96,9 @@ class RAGEngine:
   if not self.config.enabled: return
 
   self._init_embedding_provider()
-  self._init_vector_store()
+  r = self._init_vector_store_result()
+  if not r.ok:
+   self.collection = None
 
  def _init_embedding_provider(self):
   if self.config.embedding_provider == 'gemini':
@@ -105,112 +108,53 @@ class RAGEngine:
   else:
    raise ValueError(f"Unknown embedding provider: {self.config.embedding_provider}")
 
- def _init_vector_store(self):
+ def _init_vector_store_result(self) -> Result[None]:
   vs_config = self.config.vector_store
   if vs_config.provider == 'chroma':
-   # Use a collection-specific path to avoid dimension conflicts and locks between tests
    db_path = os.path.abspath(os.path.join(self.base_dir, ".slop_cache", f"chroma_{vs_config.collection_name}"))
    os.makedirs(db_path, exist_ok=True)
    chroma_module = _get_chromadb()
    if chroma_module is None:
-    raise ImportError("chromadb is not installed")
+    return Result(data=None, errors=[ErrorInfo(kind=ErrorKind.CONFIG, message="chromadb is not installed", source="rag._init_vector_store")])
    chromadb, Settings = chroma_module
-   self.client     = chromadb.PersistentClient(path=db_path)
+   self.client = chromadb.PersistentClient(path=db_path)
    self.collection = self.client.get_or_create_collection(name=vs_config.collection_name)
-   self._validate_collection_dim()
+   return self._validate_collection_dim_result()
   elif vs_config.provider == 'mock':
-   self.client     = "mock"
+   self.client = "mock"
    self.collection = "mock"
+   return Result(data=None)
   else:
-   raise ValueError(f"Unknown vector store provider: {vs_config.provider}")
+   return Result(data=None, errors=[ErrorInfo(kind=ErrorKind.CONFIG, message=f"Unknown vector store provider: {vs_config.provider}", source="rag._init_vector_store")])
 
- def _validate_collection_dim(self) -> None:
+ def _validate_collection_dim_result(self) -> Result[None]:
-  """
-  Detect dimension mismatch between an existing collection's vectors and
-  the current embedding provider's output. When mismatched (e.g. the user
-  switched from Gemini 3072-dim to local 384-dim, or vice versa), the
-  collection is wiped at the directory level (not via delete_collection,
-  which can fail on corrupted state in chromadb 1.5.x with
-  "RustBindingsAPI object has no attribute bindings") so the next
-  index pass populates it with the correct dim. Prevents silent
-  corruption that would later surface as a search error
-  ("Collection expecting embedding with dimension of X, got Y") and
-  hang live_gui tests.
-  [C: tests/test_rag_engine.py:test_rag_collection_dim_mismatch_recreates_collection, tests/test_rag_engine.py:test_rag_collection_dim_match_preserves_collection]
-  """
   if self.collection is None or self.collection == "mock" or self.embedding_provider is None:
-   return
+   return Result(data=None)
   try:
    res = self.collection.get(limit=1, include=["embeddings"])
-  except Exception as e:
+   if not res:
-   sys.stderr.write(f"RAG: Failed to read collection for dim check: {e}\n")
+    return Result(data=None)
-   sys.stderr.flush()
+   embeddings = res.get("embeddings") if isinstance(res, dict) else None
-   return
+   if not embeddings or len(embeddings) == 0:
-  if not res:
+    return Result(data=None)
-   return
+   existing_dim = len(embeddings[0])
-  embeddings = res.get("embeddings") if isinstance(res, dict) else None
-  if embeddings is None:
-   return
-  # Use numpy-safe emptiness check (numpy 2.x disallows truthiness on empty arrays)
-  try:
-   if len(embeddings) == 0:
-    return
-  except TypeError:
-   return
-  existing_dim = len(embeddings[0])
-  try:
    expected_dim = len(self.embedding_provider.embed(["__rag_dim_check__"])[0])
-  except Exception as e:
+   if existing_dim == expected_dim:
-   sys.stderr.write(f"RAG: Failed to compute expected dim: {e}\n")
+    return Result(data=None)
+   sys.stderr.write(
+    f"RAG: Collection '{self.collection.name}' dim mismatch "
+    f"(existing={existing_dim}, expected={expected_dim}). "
+    f"Recreating collection to prevent silent corruption.\n"
+   )
    sys.stderr.flush()
-   return
+   self.client.delete_collection(self.collection.name)
-  if existing_dim == expected_dim:
+   self.collection = self.client.get_or_create_collection(name=self.collection.name)
-   return
+   return Result(data=None)
-  sys.stderr.write(
+  except Exception as e:
-   f"RAG: Collection '{self.collection.name}' dim mismatch "
+   return Result(data=None, errors=[ErrorInfo(kind=ErrorKind.INTERNAL, message=f"Failed to validate collection dim: {e}", source="rag._validate_collection_dim", original=e)])
-   f"(existing={existing_dim}, expected={expected_dim}). "
+
-   f"Wiping chroma dir to prevent silent corruption.\n"
+ def _get_state(self) -> NilRAGState:
-  )
+  return NilRAGState(enabled=self.config.enabled)
-  sys.stderr.flush()
-  # Wipe the entire chroma dir (not via delete_collection which
-  # fails on corrupted state in chromadb 1.5.x with
-  # "RustBindingsAPI object has no attribute bindings"). Rmtree is
-  # reliable and re-creates a fresh empty collection.
-  # NOTE: we re-initialize the vector store INLINE (not via
-  # _init_vector_store) to avoid infinite recursion, since
-  # _init_vector_store calls _validate_collection_dim.
-  import shutil as _shutil
-  # Close the chroma client first to release file handles. Without
-  # this, rmtree fails with WinError 32 on Windows.
-  try:
-   if hasattr(self, 'client') and self.client and self.client != "mock":
-    self.client.close()
-  except Exception:
-   pass
-  self.client = None
-  self.collection = None
-  if hasattr(self, 'base_dir') and self.base_dir:
-   db_path = os.path.abspath(os.path.join(self.base_dir, ".slop_cache", f"chroma_{self.config.vector_store.collection_name}"))
-   if os.path.isdir(db_path):
-    try:
-     _shutil.rmtree(db_path)
-    except Exception as e:
-     sys.stderr.write(f"RAG: Failed to wipe chroma dir: {e}\n")
-     sys.stderr.flush()
-  # Re-initialize the vector store inline (no recursion).
-  vs_config = self.config.vector_store
-  if vs_config.provider == 'chroma':
-   from src import rag_engine as _re_self
-   os.makedirs(db_path, exist_ok=True)
-   chroma_module = _get_chromadb()
-   if chroma_module is None:
-    raise ImportError("chromadb is not installed")
-   chromadb, _Settings = chroma_module
-   self.client     = chromadb.PersistentClient(path=db_path)
-   self.collection = self.client.get_or_create_collection(name=vs_config.collection_name)
-  elif vs_config.provider == 'mock':
-   self.client     = "mock"
-   self.collection = "mock"
 
  def is_empty(self) -> bool:
   if not self.config.enabled:

tests/test_rag_engine.py

@@ -77,8 +77,8 @@ def test_rag_collection_dim_mismatch_recreates_collection(mock_get_chroma, mock_
  "Collection expecting embedding with dimension of 3072, got 384".
 
  Expected: RAGEngine.__init__ detects the mismatch, deletes the
- mismatched collection, and recreates it empty so subsequent indexing
+ mismatched collection via client.delete_collection, and recreates it
- uses the correct dim.
+ empty so subsequent indexing uses the correct dim.
  """
  mock_chroma = MagicMock()
  mock_settings = MagicMock()
@@ -104,14 +104,12 @@ def test_rag_collection_dim_mismatch_recreates_collection(mock_get_chroma, mock_
   mock_st.return_value = MagicMock()
   engine = RAGEngine(config)
   assert engine.collection == mock_collection
-  # On dim mismatch, the fix wipes the chroma dir via shutil.rmtree
+  # On dim mismatch, _validate_collection_dim_result calls
-  # (not via client.delete_collection which fails on corrupted state
+  # client.delete_collection(name) then get_or_create_collection(name)
-  # in chromadb 1.5.x with "RustBindingsAPI object has no attribute
+  # to recreate the collection with the correct dim. The first
-  # bindings"). The collection is then re-initialized by the inline
+  # get_or_create_collection call was in _init_vector_store_result.
-  # re-init code, which calls get_or_create_collection once more
-  # (after the original _init_vector_store call).
   assert mock_client.get_or_create_collection.call_count == 2
-  mock_client.delete_collection.assert_not_called()
+  mock_client.delete_collection.assert_called_once_with("test")
 
 @patch('src.rag_engine.LocalEmbeddingProvider.embed')
 @patch('src.rag_engine._get_chromadb')