test: NOWAIT functionality

frappe/tests/test_db.py

@@ -15,7 +15,7 @@ from frappe.database.utils import FallBackDateTimeStr
 from frappe.query_builder import Field
 from frappe.query_builder.functions import Concat_ws
 from frappe.tests.test_query_builder import db_type_is, run_only_if
-from frappe.tests.utils import FrappeTestCase
+from frappe.tests.utils import FrappeTestCase, timeout
 from frappe.utils import add_days, now, random_string, set_request
 from frappe.utils.testutils import clear_custom_fields
 
@@ -58,13 +58,25 @@ class TestDB(FrappeTestCase):
 
 	def test_skip_locking(self):
 		with self.primary_connection():
-			name = frappe.db.get_value("User", "Administrator", "name", for_update=True, skip_locked=True)
+			name = frappe.db.get_value("User", "Administrator", for_update=True, skip_locked=True)
 			self.assertEqual(name, "Administrator")
 
 		with self.secondary_connection():
-			name = frappe.db.get_value("User", "Administrator", "name", for_update=True, skip_locked=True)
+			name = frappe.db.get_value("User", "Administrator", for_update=True, skip_locked=True)
 			self.assertFalse(name)
 
+	@timeout(5, "Lock timeout should have been 0")
+	def test_no_wait(self):
+		with self.primary_connection():
+			name = frappe.db.get_value("User", "Administrator", for_update=True)
+			self.assertEqual(name, "Administrator")
+
+		with self.secondary_connection():
+			self.assertRaises(
+				frappe.QueryTimeoutError,
+				lambda: frappe.db.get_value("User", "Administrator", for_update=True, wait=False),
+			)
+
 	@patch.dict(frappe.conf, {"http_timeout": 20, "enable_db_statement_timeout": 1})
 	def test_db_timeout_computation(self):
 		set_request(method="GET", path="/")

frappe/tests/test_document.py

@@ -9,7 +9,7 @@ from frappe.app import make_form_dict
 from frappe.core.doctype.doctype.test_doctype import new_doctype
 from frappe.desk.doctype.note.note import Note
 from frappe.model.naming import make_autoname, parse_naming_series, revert_series_if_last
-from frappe.tests.utils import FrappeTestCase
+from frappe.tests.utils import FrappeTestCase, timeout
 from frappe.utils import cint, now_datetime, set_request
 from frappe.website.serve import get_response
 
@@ -492,6 +492,20 @@ class TestDocument(FrappeTestCase):
 		changed_val = frappe.db.get_single_value(c.doctype, key)
 		self.assertEqual(val, changed_val)
 
+	@timeout(5, "Deletion stuck on lock timeout")
+	def test_delete_race_condition(self):
+		note = frappe.new_doc("Note")
+		note.title = note.content = frappe.generate_hash()
+		note.insert()
+		frappe.db.commit()  # ensure that second connection can see the document
+
+		with self.primary_connection():
+			n1 = frappe.get_doc(note.doctype, note.name)
+			n1.save()
+
+		with self.secondary_connection():
+			self.assertRaises(frappe.QueryTimeoutError, frappe.delete_doc, note.doctype, note.name)
+
 
 class TestDocumentWebView(FrappeTestCase):
 	def get(self, path, user="Guest"):

frappe/tests/utils.py

@@ -119,6 +119,11 @@ class FrappeTestCase(unittest.TestCase):
 			yield
 		finally:
 			frappe.local.db = current_conn
+			self.addCleanup(self._rollback_connections)
+
+	def _rollback_connections(self):
+		self._primary_connection.rollback()
+		self._secondary_connection.rollback()
 
 	def assertQueryEqual(self, first: str, second: str):
 		self.assertEqual(self.normalize_sql(first), self.normalize_sql(second))