review: wrap cursorDiskKV reads in _safe_fetchall (#31, round 4)

CodeRabbit flagged that the five ``global_db.execute(...).fetchall()``
calls in assemble_workspace_tabs could raise sqlite3.Error (e.g. a
missing or corrupt cursorDiskKV table) and abort the whole tabs
endpoint. Matches the resilience pattern already applied to
_infer_workspace_name_from_context in round 3.

Add a local ``_safe_fetchall(query, params=()) -> list`` helper inside
assemble_workspace_tabs that catches sqlite3.Error and returns []. All
five call sites — bubbleId LIKE, codeBlockDiff LIKE, two
messageRequestContext LIKEs, and the composerData fetch — route
through it. The route now returns ``{"tabs": []}, 200`` instead of
500-ing when the schema is corrupt.

Regression: tests/test_workspace_tabs_sql_errors.py seeds a real
globalStorage/state.vscdb without cursorDiskKV → asserts the response
is ({"tabs": []}, 200) and no sqlite3.Error propagates.

196 tests pass (was 195; +1 new).

Author: timon0305

services/workspace_tabs.py

@@ -3,6 +3,7 @@
 import json
 import os
 import re
+import sqlite3
 from datetime import datetime
 
 from utils.path_helpers import (
@@ -83,8 +84,14 @@ def assemble_workspace_tabs(
 
         workspace_display_name = _get_workspace_display_name(workspace_path, workspace_id)
 
+        def _safe_fetchall(query: str, params: tuple = ()) -> list:
+            try:
+                return global_db.execute(query, params).fetchall()
+            except sqlite3.Error:
+                return []
+
         # Load bubbles
-        for row in global_db.execute("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'bubbleId:%'"):
+        for row in _safe_fetchall("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'bubbleId:%'"):
             parts = row["key"].split(":")
             if len(parts) >= 3:
                 bid = parts[2]
@@ -96,7 +103,7 @@ def assemble_workspace_tabs(
                     pass
 
         # Load codeBlockDiffs
-        for row in global_db.execute("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'codeBlockDiff:%'"):
+        for row in _safe_fetchall("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'codeBlockDiff:%'"):
             chat_id = _extract_chat_id_from_code_block_diff_key(row["key"])
             if not chat_id:
                 continue
@@ -110,7 +117,7 @@ def assemble_workspace_tabs(
                 pass
 
         # Load messageRequestContext
-        for row in global_db.execute("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'messageRequestContext:%'"):
+        for row in _safe_fetchall("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'messageRequestContext:%'"):
             parts = row["key"].split(":")
             if len(parts) >= 3:
                 chat_id = parts[1]
@@ -126,7 +133,7 @@ def assemble_workspace_tabs(
 
         # Build projectLayoutsMap
         project_layouts_map: dict[str, list] = {}
-        for row in global_db.execute("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'messageRequestContext:%'"):
+        for row in _safe_fetchall("SELECT key, value FROM cursorDiskKV WHERE key LIKE 'messageRequestContext:%'"):
             parts = row["key"].split(":")
             if len(parts) >= 2:
                 cid = parts[1]
@@ -147,11 +154,11 @@ def assemble_workspace_tabs(
                     pass
 
         # Get composer data entries with conversations
-        composer_rows = global_db.execute(
+        composer_rows = _safe_fetchall(
             "SELECT key, value FROM cursorDiskKV WHERE key LIKE 'composerData:%'"
             " AND value LIKE '%fullConversationHeadersOnly%'"
             " AND value NOT LIKE '%fullConversationHeadersOnly\":[]%'"
-        ).fetchall()
+        )
 
         invalid_workspace_aliases = _infer_invalid_workspace_aliases(
             composer_rows=composer_rows,

tests/test_workspace_tabs_sql_errors.py

@@ -0,0 +1,58 @@
+from __future__ import annotations
+
+import json
+import os
+import sqlite3
+import sys
+import tempfile
+import unittest
+
+from flask import Flask
+
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if REPO_ROOT not in sys.path:
+    sys.path.insert(0, REPO_ROOT)
+
+from services.workspace_tabs import assemble_workspace_tabs
+
+
+def _seed_workspace_with_corrupt_global_db(parent: str) -> str:
+    ws_root = os.path.join(parent, "workspaceStorage")
+    global_root = os.path.join(parent, "globalStorage")
+    os.makedirs(ws_root, exist_ok=True)
+    os.makedirs(global_root, exist_ok=True)
+    ws_dir = os.path.join(ws_root, "ws-a")
+    os.makedirs(ws_dir, exist_ok=True)
+    with open(os.path.join(ws_dir, "workspace.json"), "w") as f:
+        json.dump({"folder": "/tmp/proj"}, f)
+    sqlite3.connect(os.path.join(ws_dir, "state.vscdb")).close()
+
+    # Global DB exists but cursorDiskKV is missing → every LIKE query
+    # in assemble_workspace_tabs raises sqlite3.OperationalError.
+    conn = sqlite3.connect(os.path.join(global_root, "state.vscdb"))
+    conn.execute("CREATE TABLE other (x INTEGER)")
+    conn.commit()
+    conn.close()
+    return ws_root
+
+
+class TestCursorDiskKvCorruptDoesNot500(unittest.TestCase):
+    def test_missing_cursordiskkv_returns_empty_tabs_not_error(self) -> None:
+        app = Flask(__name__)
+        app.config["TESTING"] = True
+        app.config["EXCLUSION_RULES"] = []
+
+        with tempfile.TemporaryDirectory() as tmp:
+            ws_root = _seed_workspace_with_corrupt_global_db(tmp)
+            with app.test_request_context("/api/workspaces/global/tabs"):
+                try:
+                    payload, status = assemble_workspace_tabs("global", ws_root, rules=[])
+                except sqlite3.Error:
+                    self.fail("sqlite3.Error should be caught, not propagated")
+
+        self.assertEqual(status, 200)
+        self.assertEqual(payload, {"tabs": []})
+
+
+if __name__ == "__main__":
+    unittest.main()