Update and add database tests

tests/test_database.py

@@ -1,6 +1,7 @@
 from datetime import datetime
 from pytest import fixture
 
+from sqlalchemy.exc import IntegrityError
 import sqlalchemy.orm
 
 import data.database as db
@@ -13,19 +14,41 @@ def db_session() -> db.dal.Session:
 
 
 def test_base() -> None:
+    """Test to ensure db.Base() is a sqlalchemy DeclarativeBase object."""
     assert isinstance(db.Base(), sqlalchemy.orm.DeclarativeBase)
 
 
 def test_powerball_draw_by_date_blank(db_session) -> None:
-    session = db_session
-
-    blank_results = session.query(db.PowerballDraw).filter_by(draw_date='').all()
-    assert blank_results == []
+    """
+        Test that a null record is returned when no date is provided and that no dateless
+        records can exist in the table.
+    """
+    with db_session as session:
+        blank_results = session.query(db.PowerballDraw).filter_by(draw_date='').all()
+        assert blank_results == []
 
 
 def test_powerball_draw_by_date(db_session) -> None:
-    session = db_session
-    date = datetime(2010, 2, 3).strftime('%Y-%m-%d')
+    """Test to be sure we can find the first draw in the table by date."""
+    with db_session as session:
+        date = datetime(2010, 2, 3).date()
+        draw = db.PowerballDraw(draw_date=date, white_ball1=17, white_ball2=22, white_ball3=36, white_ball4=37,
+             white_ball5=52, powerball=24, power_play=2)
 
-    record = session.query(db.PowerballDraw).filter_by(draw_date=date).first()
-    assert record.draw_date.strftime('%Y-%m-%d') == date
+        record = session.query(db.PowerballDraw).filter_by(draw_date=date).first()
+        assert record == draw
+
+
+def test_powerball_draw_integrity(db_session) -> None:
+    """Test that a proper error is received when a duplicate value insertion is attempted."""
+    with db_session as session:
+        date = datetime.strptime('02/03/2010','%m/%d/%Y').date()
+
+        try:
+            draw = db.PowerballDraw(draw_date=date, white_ball1=17, white_ball2=22, white_ball3=36, white_ball4=37,
+                    white_ball5=52, powerball=24, power_play=2)
+            session.add(draw)
+            session.commit()
+            assert False
+        except IntegrityError:
+            assert True