Fix psycopg3 tests

Several tests (such as SQLPanelTestCase.test_cursor_wrapper_singleton)
are written to ensure that only a single cursor wrapper is instantiated
during the test.  However, this fails when using Django's psycopg3
backend, since the .last_executed_query() call in
NormalCursorWrapper._record() ends up creating an additional cursor (via
[1]).  To avoid this wrapping this additional cursor, set the
DatabaseWrapper's ._djdt_logger attribute to None before calling
.last_executed_query() and restore it when finished.  This will cause
the monkey-patched DatabaseWrapper .cursor() and .chunked_cursor()
methods to return the original cursor without wrapping during that call.

[1] https://github.com/django/django/blob/4.2.1/django/db/backends/postgresql/psycopg_any.py#L21

Author: living180

debug_toolbar/panels/sql/tracking.py

@@ -144,6 +144,21 @@ def _decode(self, param):
         except UnicodeDecodeError:
             return "(encoded string)"
 
+    def _last_executed_query(self, sql, params):
+        """Get the last executed query from the connection."""
+        # Django's psycopg3 backend creates a new cursor in its implementation of the
+        # .last_executed_query() method.  To avoid wrapping that cursor, temporarily set
+        # the DatabaseWrapper's ._djdt_logger attribute to None.  This will cause the
+        # monkey-patched .cursor() and .chunked_cursor() methods to skip the wrapping
+        # process during the .last_executed_query() call.
+        self.db._djdt_logger = None
+        try:
+            return self.db.ops.last_executed_query(
+                self.cursor, sql, self._quote_params(params)
+            )
+        finally:
+            self.db._djdt_logger = self.logger
+
     def _record(self, method, sql, params):
         alias = self.db.alias
         vendor = self.db.vendor
@@ -176,17 +191,17 @@ def _record(self, method, sql, params):
             params = {
                 "vendor": vendor,
                 "alias": alias,
-                "sql": self.db.ops.last_executed_query(
-                    self.cursor, sql, self._quote_params(params)
-                ),
+                "sql": self._last_executed_query(sql, params),
                 "duration": duration,
                 "raw_sql": sql,
                 "params": _params,
                 "raw_params": params,
                 "stacktrace": get_stack_trace(skip=2),
                 "start_time": start_time,
                 "stop_time": stop_time,
-                "is_slow": duration > dt_settings.get_config()["SQL_WARNING_THRESHOLD"],
+                "is_slow": (
+                    duration > dt_settings.get_config()["SQL_WARNING_THRESHOLD"]
+                ),
                 "is_select": sql.lower().strip().startswith("select"),
                 "template_info": template_info,
             }