Opened 9 months ago
Closed 9 months ago
#35226 closed Bug (fixed)
Dynamically created connection are disallowed in SimpleTestCase and subclasses.
Reported by: | Florian Apolloner | Owned by: | Mariusz Felisiak |
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Component: | Testing framework | Version: | dev |
Severity: | Release blocker | Keywords: | |
Cc: | Florian Apolloner, David Wobrock | Triage Stage: | Accepted |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description (last modified by )
While working on connection pooling for postgres I ran into the following regression (since 8fb0be3500cc7519a56985b1b6f415d75ac6fedb):
from django.db import connection from django.test import TestCase class Test(TestCase): def test_something(self): new_connection = connection.copy("asd") with new_connection.cursor() as cursor: print(cursor.execute("SELECT 1").fetchall())
On 5.0 this works fine, on main this fails with:
django.test.testcases.DatabaseOperationForbidden: Database threaded connections to 'asd' are not allowed in this test. Add 'asd' to test_regression.Test.databases to ensure proper test isolation and silence this failure.
I cannot really add this to databases
since this is a dynamically created database. I am opening this as release blocker so it doesn't get lost (I might be holding it wrong though)
Change History (7)
comment:1 by , 9 months ago
Description: | modified (diff) |
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comment:2 by , 9 months ago
Well I will see if I can get around it without an alias change in the pool tests, but testing the pooling stuff is tricky without creating completely new connections :D
EDIT:// I was able to work around it for my tests, we will see if the full testsuite on jenkins agrees with my changes.
comment:3 by , 9 months ago
We could ignore dynamically created connections, e.g.:
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django/test/testcases.py
diff --git a/django/test/testcases.py b/django/test/testcases.py index 51b07ae50d..768ebd7d52 100644
a b class SimpleTestCase(unittest.TestCase): 280 280 self.connection is None 281 281 and self.alias not in cls.databases 282 282 and self.alias != NO_DB_ALIAS 283 and self.alias in connections 283 284 ): 284 285 # Connection has not yet been established, but the alias is not allowed. 285 286 message = cls._disallowed_database_msg % {
What do you think?
follow-up: 5 comment:4 by , 9 months ago
That seems like a workable solution to me if it doesn't conflict with what you have been trying to achieve in the first place 👍
comment:5 by , 9 months ago
Cc: | added |
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Owner: | changed from | to
Status: | new → assigned |
Summary: | Copying a connection with a new alias fails → Dynamically created connection are disallowed in SimpleTestCase and subclasses. |
Triage Stage: | Unreviewed → Accepted |
Version: | 5.0 → dev |
Replying to Florian Apolloner:
That seems like a workable solution to me if it doesn't conflict with what you have been trying to achieve in the first place 👍
Thanks, let's try.
TBH, I don't see how we could handle this and keep 8fb0be3500cc7519a56985b1b6f415d75ac6fedb. The main question is, do we want to support something like this? Creating a copy of the connection copy is tricky, and if you change the alias in the meantime it becomes even more complicated.