Add Python 3.15 support

.github/workflows/pre-commit.yml

@@ -23,6 +23,7 @@ jobs:
           - "3.12"
           - "3.13"
           - "3.14"
+          - "3.15"
 
     steps:
     - uses: actions/checkout@v7

.github/workflows/smoke-test.yml

@@ -83,16 +83,15 @@ jobs:
         os:
           - ubuntu-24.04
         # The floor in pyproject.toml (requires-python >=3.9) up to the newest
-        # final release. 3.15 is absent deliberately: as of 2026-09-18 it is at
-        # rc2 (GA 2026-10-01), and setup-python needs allow-prereleases plus an
-        # explicit "3.15.0-rc.2" to install it. Add a bare "3.15" once it ships.
+        # final release.
         python-version:
           - "3.9"
           - "3.10"
           - "3.11"
           - "3.12"
           - "3.13"
           - "3.14"
+          - "3.15"
         driver:
           - mysql
           - https
@@ -154,7 +153,11 @@ jobs:
 
       - name: Run tests
         if: ${{ matrix.driver != 'https' }}
-        run: pytest -v --pyargs singlestoredb.tests.test_basics
+        # test_asgi_env_file needs no database; it is here, and not in the
+        # https step, to run once on each Python version. It covers the zip
+        # loader in asgi.main(), which differs between 3.9 and 3.10+ and broke
+        # on 3.15.
+        run: pytest -v --pyargs singlestoredb.tests.test_basics singlestoredb.tests.test_asgi_env_file
         env:
           PYTHONPATH: ${{ github.workspace }}
           # CLUSTER_PASSWORD goes into the userinfo half of a URL here, so it

singlestoredb/functions/ext/asgi.py

@@ -2442,9 +2442,31 @@ def main(argv: Optional[List[str]] = None) -> None:
             # Load zip file as a module
             modname = os.path.splitext(os.path.basename(envs[0]))[0]
             zi = zipimport.zipimporter(envs[0])
-            mod = zi.load_module(modname)
-            if mod is None:
-                raise RuntimeError(f'environment file could not be imported: {envs[0]}')
+            # zipimporter.load_module() was removed in Python 3.15, and
+            # find_spec()/exec_module() only exist from Python 3.10. The else
+            # branch is only for Python 3.9 compatibility and can be dropped
+            # as soon as Python 3.9 support is dropped.
+            if sys.version_info >= (3, 10):
+                spec = zi.find_spec(modname)
+                if spec is None or spec.loader is None:
+                    raise RuntimeError(
+                        f'environment file could not be imported: {envs[0]}',
+                    )
+                mod = importlib.util.module_from_spec(spec)
+                sys.modules[modname] = mod
+                try:
+                    spec.loader.exec_module(mod)
+                except BaseException:
+                    # Match load_module(): don't leave a half-initialized
+                    # module behind for a later import to pick up
+                    sys.modules.pop(modname, None)
+                    raise
+            else:
+                mod = zi.load_module(modname)
+                if mod is None:
+                    raise RuntimeError(
+                        f'environment file could not be imported: {envs[0]}',
+                    )
             functions = [mod]
 
             if defaults:

singlestoredb/tests/test_asgi_env_file.py

@@ -0,0 +1,91 @@
+"""Tests for loading a zipped environment file through ``asgi.main()``."""
+import os
+import sys
+import tempfile
+import textwrap
+import unittest
+import uuid
+import zipfile
+from types import ModuleType
+from typing import Optional
+from unittest.mock import MagicMock
+from unittest.mock import patch
+
+from ..functions.ext import asgi
+
+
+GOOD_MODULE = textwrap.dedent('''
+    from singlestoredb.functions import udf
+
+    @udf
+    def env_file_double(x: int) -> int:
+        return x * 2
+''')
+
+FAILING_MODULE = textwrap.dedent('''
+    raise RuntimeError('environment init failed')
+''')
+
+
+class TestEnvironmentFile(unittest.TestCase):
+    """``main()`` imports the module inside a zip passed as the function source.
+
+    Python 3.15 removed ``zipimporter.load_module()``, which this path used
+    to rely on. uvicorn is mocked out, so no server is started.
+    """
+
+    def setUp(self) -> None:
+        self.tmpdir = tempfile.TemporaryDirectory()
+        self.addCleanup(self.tmpdir.cleanup)
+        # A unique name per test, so no module cached in sys.modules from
+        # an earlier test can satisfy the import
+        self.modname = f'envfile_{uuid.uuid4().hex}'
+        self.addCleanup(sys.modules.pop, self.modname, None)
+        self.cached_module: Optional[ModuleType] = None
+
+    def _make_env(self, source: str) -> str:
+        path = os.path.join(self.tmpdir.name, f'{self.modname}.zip')
+        with zipfile.ZipFile(path, 'w') as zf:
+            zf.writestr(f'{self.modname}/__init__.py', source)
+        return path
+
+    def _run_main(self, env_path: str) -> MagicMock:
+        """Run ``main()`` on the environment file and return the mocked uvicorn.
+
+        What ``sys.modules`` holds for the environment module is saved to
+        ``self.cached_module`` before ``patch.dict`` exits, since restoring
+        ``sys.modules`` would otherwise drop the entry. It is saved even when
+        ``main()`` raises.
+
+        """
+        uvicorn = MagicMock()
+        with patch.dict(sys.modules, {'uvicorn': uvicorn}):
+            try:
+                # An empty --db skips registering the functions with a database
+                asgi.main(['--db', '', env_path])
+            finally:
+                self.cached_module = sys.modules.get(self.modname)
+        return uvicorn
+
+    def test_module_is_loaded_and_functions_found(self) -> None:
+        uvicorn = self._run_main(self._make_env(GOOD_MODULE))
+
+        uvicorn.run.assert_called_once()
+        app = uvicorn.run.call_args.args[0]
+        names = [info['signature']['name'] for _, info in app.endpoints.values()]
+        self.assertEqual(names, ['env_file_double'])
+
+        mod = self.cached_module
+        assert mod is not None
+        self.assertEqual(mod.env_file_double(21), 42)
+        self.assertTrue(str(mod.__file__).startswith(self.tmpdir.name))
+
+    def test_failed_import_is_not_cached(self) -> None:
+        with self.assertRaisesRegex(RuntimeError, 'environment init failed'):
+            self._run_main(self._make_env(FAILING_MODULE))
+
+        self.assertIsNone(self.cached_module)
+
+
+if __name__ == '__main__':
+    unittest.main()