added first test case and some comments

test_create_movie.py

@@ -5,14 +5,24 @@ from main import MoviesApp
 
 
 class TestCreateMovie(TestCase):
+
+    def test_create_movie_inserts_movies_weak(self):
+        url = MovieDatabase.construct_in_memory_url()
+        movie_database = MovieDatabase(url)
+        movie_database.ensure_tables_exist()
+        session = movie_database.create_session()
+        MoviesApp._create_movie(session, 'Example', 4000000, 290000000)
+        actual = session.query(Movie).filter(Movie.title == 'Example').one()
+        # implicit oracle
+
     def test_create_movie_inserts_movies(self):
         url = MovieDatabase.construct_in_memory_url()
         movie_database = MovieDatabase(url)
         movie_database.ensure_tables_exist()
         session = movie_database.create_session()
         MoviesApp._create_movie(session, 'Example', 4000000, 290000000)
-        actual = session.query(Movie).filter(Movie.title == 'Example').first()
-        self.assertIsNotNone(actual)
+        actual = session.query(Movie).filter(Movie.title == 'Example').one()
+        self.assertIsNotNone(actual) # not as weak oracle (but still weak)
 
     def test_create_movie_inserts_one_movie(self):
         url = MovieDatabase.construct_in_memory_url()
@@ -21,7 +31,7 @@ class TestCreateMovie(TestCase):
         session = movie_database.create_session()
         MoviesApp._create_movie(session, 'Example', 4000000, 290000000)
         actual = session.query(Movie).filter(Movie.title == 'Example').count()
-        self.assertEqual(actual, 1)
+        self.assertEqual(actual, 1) # weak oracle
 
     def test_create_movie_inserts_correct_dollar_figures(self):
         url = MovieDatabase.construct_in_memory_url()
@@ -29,6 +39,6 @@ class TestCreateMovie(TestCase):
         movie_database.ensure_tables_exist()
         session = movie_database.create_session()
         MoviesApp._create_movie(session, 'Example', 4000000, 290000000)
-        actual = session.query(Movie).filter(Movie.title == 'Example').first()
+        actual = session.query(Movie).filter(Movie.title == 'Example').one()
         self.assertEqual(actual.budget, 4000000)
-        self.assertEqual(actual.gross_revenue, 290000000)
+        self.assertEqual(actual.gross_revenue, 290000000) # better