feat: add app handler methods save_setting(), delete_setting()

tests/test_app.py

@@ -97,6 +97,68 @@ class TestAppHandler(TestCase):
         value = self.app.get_setting(session, 'foo')
         self.assertEqual(value, 'bar')
 
+    def test_save_setting(self):
+        try:
+            import sqlalchemy as sa
+            from sqlalchemy import orm
+        except ImportError:
+            pytest.skip("test is not relevant without sqlalchemy")
+
+        Session = orm.sessionmaker()
+        engine = sa.create_engine('sqlite://')
+        session = Session(bind=engine)
+        session.execute(sa.text("""
+        create table setting (
+                name varchar(255) primary key,
+                value text
+        );
+        """))
+        session.commit()
+
+        # value null by default
+        value = self.app.get_setting(session, 'foo')
+        self.assertIsNone(value)
+
+        # unless we save a value
+        self.app.save_setting(session, 'foo', '1')
+        session.commit()
+        value = self.app.get_setting(session, 'foo')
+        self.assertEqual(value, '1')
+
+    def test_delete_setting(self):
+        try:
+            import sqlalchemy as sa
+            from sqlalchemy import orm
+        except ImportError:
+            pytest.skip("test is not relevant without sqlalchemy")
+
+        Session = orm.sessionmaker()
+        engine = sa.create_engine('sqlite://')
+        session = Session(bind=engine)
+        session.execute(sa.text("""
+        create table setting (
+                name varchar(255) primary key,
+                value text
+        );
+        """))
+        session.commit()
+
+        # value null by default
+        value = self.app.get_setting(session, 'foo')
+        self.assertIsNone(value)
+
+        # unless we save a value
+        self.app.save_setting(session, 'foo', '1')
+        session.commit()
+        value = self.app.get_setting(session, 'foo')
+        self.assertEqual(value, '1')
+
+        # but then if we delete it, should be null again
+        self.app.delete_setting(session, 'foo')
+        session.commit()
+        value = self.app.get_setting(session, 'foo')
+        self.assertIsNone(value)
+
     def test_model(self):
         try:
             from wuttjamaican.db import model