fix: consolidate _default_db_path to utils.py — closes #40

scripts/commands/graph_schema.py

@@ -16,6 +16,7 @@
 from typing import Any, Dict, Optional
 
 from commands import register_command
+from utils import default_db_path
 
 
 def add_args(parser):
@@ -26,11 +27,6 @@ def add_args(parser):
                         help="Custom path for SQLite database file")
 
 
-def _default_db_path(workspace: str) -> str:
-    """Return the default SQLite db path for a workspace."""
-    return os.path.join(workspace, ".codelens", "codelens.db")
-
-
 def get_graph_schema(workspace: str, db_path: Optional[str] = None) -> Dict[str, Any]:
     """Return the shape of the graph (node/edge counts + type distribution).
 
@@ -48,7 +44,7 @@ def get_graph_schema(workspace: str, db_path: Optional[str] = None) -> Dict[str,
         ``indexes``, ``status``, and ``workspace``.
     """
     workspace = os.path.abspath(workspace)
-    db_path = db_path or _default_db_path(workspace)
+    db_path = db_path or default_db_path(workspace)
 
     schema: Dict[str, Any] = {
         "status": "ok",

scripts/graph_model.py

@@ -50,7 +50,7 @@
 from collections import deque
 from typing import Any, Dict, Iterable, List, Optional, Set, Tuple
 
-from utils import logger
+from utils import default_db_path, logger
 
 
 # ─── Schema Constants ─────────────────────────────────────────
@@ -158,9 +158,11 @@ def init_graph_schema(conn: sqlite3.Connection) -> None:
 
 # ─── Population ───────────────────────────────────────────────
 
-def _default_db_path(workspace: str) -> str:
-    """Return the default SQLite db path for a workspace."""
-    return os.path.join(workspace, ".codelens", "codelens.db")
+# Single source of truth for the default db path lives in utils.default_db_path
+# (see issue #40). The private alias below is kept for backward compatibility
+# with tests and callers that import ``graph_model._default_db_path`` directly;
+# it delegates to the canonical helper so logic never drifts.
+_default_db_path = default_db_path
 
 
 def _parse_file_line_from_node_id(node_id: str) -> Tuple[str, int]:
@@ -244,7 +246,7 @@ def populate_graph_tables(workspace: str, db_path: Optional[str] = None) -> Dict
         Dict with keys 'nodes' and 'edges' giving the number of rows inserted.
     """
     workspace = os.path.abspath(workspace)
-    db_path = db_path or _default_db_path(workspace)
+    db_path = db_path or default_db_path(workspace)
 
     # Lazy import to avoid circular dependency at module load time.
     from registry import load_backend_registry
@@ -430,7 +432,7 @@ def incremental_graph_update(
           unresolved after the post-pass.
     """
     workspace = os.path.abspath(workspace)
-    db_path = db_path or _default_db_path(workspace)
+    db_path = db_path or default_db_path(workspace)
 
     # Normalize changed_files to workspace-relative paths. We accept any
     # iterable (list, set, tuple) and de-duplicate via a set.

scripts/persistent_registry.py

@@ -27,12 +27,15 @@
 from datetime import datetime, timezone
 from typing import Any, Dict, List, Optional, Set, Tuple
 
-from utils import logger
+from utils import default_db_path, logger
 
 
 # ─── Schema Version ────────────────────────────────────────────
 
 SCHEMA_VERSION = 1
+# Module-level constant kept for backwards-compat with external callers/plugins
+# that may import ``DB_FILENAME``. Internal path construction now goes through
+# ``utils.default_db_path`` (single source of truth — see issue #40).
 DB_FILENAME = "codelens.db"
 
 # ─── SQL Statements ────────────────────────────────────────────
@@ -129,9 +132,7 @@ def __init__(self, workspace: str, db_path: Optional[str] = None):
                      Defaults to .codelens/codelens.db
         """
         self.workspace = workspace
-        self._db_path = db_path or os.path.join(
-            workspace, ".codelens", DB_FILENAME
-        )
+        self._db_path = db_path or default_db_path(workspace)
         self._local = threading.local()  # Thread-local storage for connections
         self._initialized = False
         self._init_lock = threading.Lock()
@@ -855,7 +856,7 @@ def vacuum(self) -> None:
 
 def db_exists(workspace: str, db_path: Optional[str] = None) -> bool:
     """Check if a CodeLens SQLite database exists for the workspace."""
-    path = db_path or os.path.join(workspace, ".codelens", DB_FILENAME)
+    path = db_path or default_db_path(workspace)
     return os.path.exists(path)
 
 

scripts/utils.py

@@ -40,6 +40,29 @@ def get_logger(name: str = "codelens") -> logging.Logger:
     '.chunk.js', '.d.ts',  # declaration files
 })
 
+# ─── Storage Path Resolution ──────────────────────────────────
+
+
+def default_db_path(workspace: str) -> str:
+    """Return the default SQLite database path for a workspace.
+
+    Single source of truth for the default CodeLens database location.
+    Previously triplicated across ``scripts/commands/graph_schema.py``,
+    ``scripts/graph_model.py``, and ``scripts/persistent_registry.py``
+    (see issue #40). Any future change to the default path — e.g.,
+    honoring a ``CODELENS_DB_PATH`` environment variable or moving the
+    database out of ``.codelens/`` — only needs to be made here.
+
+    Args:
+        workspace: Absolute or relative path to the workspace root.
+
+    Returns:
+        Path to the default SQLite database file:
+        ``<workspace>/.codelens/codelens.db``.
+    """
+    return os.path.join(workspace, ".codelens", "codelens.db")
+
+
 # ─── Output File Generation ─────────────────────────────────
 
 def write_output_files(workspace: str, scan_result, max_files: int = 3000) -> dict:

tests/test_graph_model.py

@@ -514,3 +514,79 @@ def test_use_graph_false_forces_flat(self, scanned_clean_app):
         )
 
         assert self._chain_set(forced_flat["chains"]["up"]) == self._chain_set(flat["chains"]["up"])
+
+
+# ─── 7. Default DB Path Consistency (issue #40) ─────────────
+
+
+class TestDefaultDbPathConsistency:
+    """Verify all three call sites resolve the default db path identically.
+
+    Issue #40: ``_default_db_path`` was duplicated in ``graph_schema.py``,
+    ``graph_model.py``, and ``persistent_registry.py``. After consolidation
+    to ``utils.default_db_path``, this test guards against future drift by
+    asserting that all three sites (plus the canonical helper) produce the
+    same path for the same workspace.
+    """
+
+    def test_default_db_path_consistency(self):
+        """All three call sites must resolve to the same db path."""
+        workspace = os.path.join(os.path.sep, "tmp", "codelens_path_test")
+
+        # 1. Canonical helper — the single source of truth.
+        from utils import default_db_path
+        canonical = default_db_path(workspace)
+
+        # 2. graph_model._default_db_path (kept as a backward-compat alias).
+        from graph_model import _default_db_path as graph_model_path
+        # 3. graph_schema used to define its own helper; it now imports
+        #    utils.default_db_path, so we exercise the public path through
+        #    the module's get_graph_schema function indirectly by checking
+        #    that the import resolves to the same callable.
+        from commands import graph_schema as graph_schema_mod
+
+        assert canonical == graph_model_path(workspace), (
+            "graph_model._default_db_path must match utils.default_db_path; "
+            f"got graph_model={graph_model_path(workspace)!r} "
+            f"vs utils={canonical!r}"
+        )
+
+        # graph_schema.py no longer defines its own _default_db_path; the
+        # module must import default_db_path from utils so its callers
+        # resolve through the same single source of truth.
+        assert hasattr(graph_schema_mod, "default_db_path"), (
+            "commands.graph_schema must import default_db_path from utils "
+            "(issue #40 consolidation)"
+        )
+        assert graph_schema_mod.default_db_path is default_db_path, (
+            "commands.graph_schema.default_db_path must be the same callable "
+            "as utils.default_db_path (not a re-definition)"
+        )
+        assert graph_schema_mod.default_db_path(workspace) == canonical, (
+            "commands.graph_schema must resolve to the same path as "
+            f"utils.default_db_path; got "
+            f"{graph_schema_mod.default_db_path(workspace)!r} "
+            f"vs {canonical!r}"
+        )
+
+        # 4. PersistentRegistry must construct the same default path when no
+        #    explicit db_path is supplied.
+        from persistent_registry import PersistentRegistry, db_exists
+        registry = PersistentRegistry(workspace)
+        assert registry.db_path == canonical, (
+            "PersistentRegistry default db_path must match utils.default_db_path; "
+            f"got registry={registry.db_path!r} vs utils={canonical!r}"
+        )
+        # db_exists() helper must also use the same default path.
+        # (We can't easily assert the path it computes without filesystem
+        # side effects, but we can assert the function does not raise and
+        # returns False for a non-existent workspace — proving it computes
+        # a path rather than crashing on the old hardcoded join.)
+        assert db_exists(workspace) is False, (
+            "db_exists must return False for a workspace with no database"
+        )
+
+        # Sanity: the canonical path has the expected shape.
+        assert canonical.endswith(os.path.join(".codelens", "codelens.db")), (
+            f"canonical path {canonical!r} must end with .codelens/codelens.db"
+        )