Replace use of utcnow() with now() for Python 3.13 compatibility, Fixes #1643

[jenstroeger]

Description

Fixes: #1643

Existing tests should cover this change.

Checklist

This pull request is:

• A documentation / typographical error fix
  • Good to go, no issue or tests are needed
• A short code fix
  • please include the issue number, and create an issue if none exists, which
    must include a complete example of the issue. one line code fixes without an
    issue and demonstration will not be accepted.
  • Please include: Fixes: #<issue number> in the commit message
  • please include tests. one line code fixes without tests will not be accepted.
• A new feature implementation
  • please include the issue number, and create an issue if none exists, which must
    include a complete example of how the feature would look.
  • Please include: Fixes: #<issue number> in the commit message
  • please include tests.

[CaselIT]

It seems that the tests are mocking something that needs updating

[jenstroeger]

Ah ok, I’ll take a look. I didn’t find a CONTRIBUTING file so this initial change was a bit of a shot in the dark 🤓

[CaselIT]

no problem, it's what the ci is for!

[sqla-tester]

OK, this is sqla-tester setting up my work on behalf of zzzeek to try to get revision 1ddb3ca of this pull request into gerrit so we can run tests and reviews and stuff

[sqla-tester]

New Gerrit review created for change 1ddb3ca: https://gerrit.sqlalchemy.org/c/sqlalchemy/alembic/+/5892

[zzzeek]

the test fails without this replace. i dont remember the reason for the replace, and it perhaps is local to the fact that the test is using mocks. not sure yet

[zzzeek]

sorry I'm just going to restore that replace, I know if I had more mental capacity right now I could change the mock on the other end but I just need to get this merged and I dont want to screw it up right now

[proby-actvo]

Maybe I'm being dumb, but doesn't datetime.datetime.now(tzinfo) achieve the desired result (the current datetime in the prescribed timezone)?

[zzzeek]

I can't get the mock in the tests to match it. i dont have time to understand why the mocks were set up the way they were and dont want to change them

[zzzeek]

diff --git a/alembic/script/base.py b/alembic/script/base.py
index 972a9bd..552dc05 100644
--- a/alembic/script/base.py
+++ b/alembic/script/base.py
@@ -605,7 +605,6 @@ class ScriptDirectory:
 
             create_date = (
                 datetime.datetime.now(tz=datetime.timezone.utc)
-                .replace(tzinfo=datetime.timezone.utc)
                 .astimezone(tzinfo)
             )
         else:
diff --git a/tests/test_script_production.py b/tests/test_script_production.py
index 4263c1e..1049357 100644
--- a/tests/test_script_production.py
+++ b/tests/test_script_production.py
@@ -235,7 +235,13 @@ class ScriptNamingTest(TestBase):
         with mock.patch(
             "alembic.script.base.datetime",
             mock.Mock(
-                datetime=mock.Mock(now=lambda tz=None: given),
+                datetime=mock.Mock(
+                    now=lambda tz=None: (
+                        given.replace(tzinfo=datetime.timezone.utc)
+                        if timezone_arg
+                        else given
+                    )
+                ),
                 timezone=datetime.timezone,
             ),
         ):

[zzzeek]

also note no tests covered this, all of them mocked utcnow(). adding one now

[sqla-tester]

Gerrit review https://gerrit.sqlalchemy.org/c/sqlalchemy/alembic/+/5892 has been merged. Congratulations! :)