Fix: Skip NULL bubble rows in workspace tabs loader (closes #50)

services/workspace_tabs.py

@@ -97,6 +97,8 @@ def _safe_fetchall(query: str, params: tuple = ()) -> list:
             parts = row["key"].split(":")
             if len(parts) >= 3:
                 bid = parts[2]
+                if row["value"] is None:
+                    continue
                 try:
                     bubble_obj = Bubble.from_dict(json.loads(row["value"]), bubble_id=bid)
                     bubble_map[bid] = bubble_obj.raw

tests/test_workspace_tabs_null_bubble.py

@@ -0,0 +1,81 @@
+"""Regression test for issue #50: NULL bubble value crashes GET /tabs.
+
+A cursorDiskKV row with a NULL value column previously caused
+json.loads(None) -> TypeError, which propagated as a 500 response.
+The fix adds an explicit None-guard before json.loads in the bubble
+loading loop of services/workspace_tabs.py.
+"""
+
+import json
+import os
+import sqlite3
+import tempfile
+import unittest
+
+
+class TestNullBubbleValueDoesNotCrashTabs(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+        base = self.tmp.name
+
+        # Minimal workspaceStorage layout expected by assemble_workspace_tabs.
+        ws_dir = os.path.join(base, "workspaceStorage")
+        os.makedirs(ws_dir)
+
+        # Global storage with a cursorDiskKV table containing a NULL-value bubble row.
+        global_dir = os.path.join(base, "globalStorage")
+        os.makedirs(global_dir)
+        db_path = os.path.join(global_dir, "state.vscdb")
+        conn = sqlite3.connect(db_path)
+        conn.execute("CREATE TABLE cursorDiskKV ([key] TEXT PRIMARY KEY, value TEXT)")
+        conn.execute(
+            "INSERT INTO cursorDiskKV ([key], value) VALUES (?, ?)",
+            ("bubbleId:composer-abc:bubble-null", None),  # NULL value — the crash case
+        )
+        # Also insert a healthy bubble so we verify good rows still load.
+        conn.execute(
+            "INSERT INTO cursorDiskKV ([key], value) VALUES (?, ?)",
+            (
+                "bubbleId:composer-abc:bubble-ok",
+                json.dumps({"type": 1, "text": "hello", "createdAt": 0}),
+            ),
+        )
+        conn.commit()
+        conn.close()
+
+        self.workspace_path = ws_dir
+
+    def tearDown(self):
+        self.tmp.cleanup()
+
+    def test_null_bubble_row_is_skipped_without_exception(self):
+        """assemble_workspace_tabs must not raise when a bubble row has NULL value."""
+        from services.workspace_tabs import assemble_workspace_tabs
+
+        try:
+            payload, status = assemble_workspace_tabs(
+                workspace_id="global",
+                workspace_path=self.workspace_path,
+                rules=[],
+            )
+        except TypeError as exc:
+            self.fail(f"NULL bubble row raised TypeError: {exc}")
+
+        self.assertEqual(status, 200)
+
+    def test_healthy_bubbles_still_load_when_null_row_present(self):
+        """Healthy bubble rows in the same table are not dropped by the None-guard."""
+        from services.workspace_tabs import assemble_workspace_tabs
+
+        payload, status = assemble_workspace_tabs(
+            workspace_id="global",
+            workspace_path=self.workspace_path,
+            rules=[],
+        )
+        self.assertEqual(status, 200)
+        self.assertIsInstance(payload, dict)
+        self.assertIn("tabs", payload)
+
+
+if __name__ == "__main__":
+    unittest.main()