debut changement vers google drive

tests/test_database_url.py

@@ -1,17 +1,17 @@
 """Which PostgreSQL driver the application actually asks for — QUA-001.
 
 `postgresql://…` is not "whichever driver is installed". SQLAlchemy reads it
-as psycopg2 and imports that module when the engine is created.
-requirements.txt pins psycopg 3 and no psycopg2, so a clean install against
-the URL Render hands out — the same form docs/database-restore.md documents
-— fails before the first request:
+as psycopg2 unless the URL names a driver. requirements.txt declares psycopg
+3, so create_app() must explicitly select it.
 
-    ModuleNotFoundError: No module named 'psycopg2'
-
-create_app() now names the driver. These tests pin that down, and the last
-one proves the failure is real rather than theoretical.
+The test suite must not assume that psycopg2 is absent: a developer's virtual
+environment can contain optional packages in addition to the declared
+dependencies. These tests instead pin the application's selected driver and
+the dependency contract that production installs use.
 """
 
+from pathlib import Path
+
 import pytest
 from sqlalchemy import create_engine
 
@@ -80,16 +80,13 @@ class TestTheFactory:
         assert app.config['SQLALCHEMY_DATABASE_URI'].startswith('sqlite:///')
 
 
-class TestTheFailureIsReal:
-    """Not a hypothetical: this is what the deployed configuration did."""
+class TestDriverContract:
+    def test_production_dependencies_select_psycopg_3(self):
+        requirements = Path(__file__).resolve().parents[1] / 'requirements.txt'
+        declared = requirements.read_text(encoding='utf-8')
 
-    def test_psycopg2_is_not_installed(self):
-        with pytest.raises(ImportError):
-            import psycopg2  # noqa: F401
-
-    def test_a_driverless_url_cannot_build_an_engine(self):
-        with pytest.raises(ModuleNotFoundError):
-            create_engine('postgresql://u:p@host/db')
+        assert 'psycopg[binary]==' in declared
+        assert 'psycopg2' not in declared
 
     def test_the_normalised_url_can(self):
         engine = create_engine(normalise_database_url('postgresql://u:p@host/db'))