remove pytest.mark.usefixtures decorator

while it's nice to use the decorator to signify fixtures with side
effects, it has unfortunate problems of completely overriding any
fixtures you've declared in the funcargs - so isn't really suitable
for our usecase where we often have other fixtures we rely on to
return values to us.

So for consistency, let's remove this and stick to using funcargs
to define our fixtures

tests/app/dao/test_users_dao.py

@@ -21,8 +21,7 @@ from app.models import User, VerifyCode
 from tests.app.db import create_user
 
 
-@pytest.mark.usefixtures('notify_db_session')
-def test_create_user():
+def test_create_user(notify_db_session):
     email = 'notify@digital.cabinet-office.gov.uk'
     data = {
         'name': 'Test User',
@@ -38,8 +37,7 @@ def test_create_user():
     assert not user.platform_admin
 
 
-@pytest.mark.usefixtures('notify_db_session')
-def test_get_all_users():
+def test_get_all_users(notify_db_session):
     create_user(email='1@test.com')
     create_user(email='2@test.com')
 
@@ -47,21 +45,18 @@ def test_get_all_users():
     assert len(get_user_by_id()) == 2
 
 
-@pytest.mark.usefixtures('notify_db_session')
-def test_get_user():
+def test_get_user(notify_db_session):
     email = '1@test.com'
     user = create_user(email=email)
     assert get_user_by_id(user_id=user.id).email_address == email
 
 
-@pytest.mark.usefixtures('notify_db_session')
-def test_get_user_not_exists(fake_uuid):
+def test_get_user_not_exists(notify_db_session, fake_uuid):
     with pytest.raises(NoResultFound):
         get_user_by_id(user_id=fake_uuid)
 
 
-@pytest.mark.usefixtures('notify_db_session')
-def test_get_user_invalid_id():
+def test_get_user_invalid_id(notify_db_session):
     with pytest.raises(DataError):
         get_user_by_id(user_id="blah")
 

tests/app/db.py

@@ -10,8 +10,8 @@ def create_user(mobile_number="+447700900986", email="notify@digital.cabinet-off
         'mobile_number': mobile_number,
         'state': 'active'
     }
-    usr = User.query.filter_by(email_address=email).first()
-    if not usr:
-        usr = User(**data)
-    save_model_user(usr)
-    return usr
+    user = User.query.filter_by(email_address=email).first()
+    if not user:
+        user = User(**data)
+    save_model_user(user)
+    return user