Fix issue #4 : correct purchasePlaces() and add unit tests

server.py

@@ -48,14 +48,20 @@ def book(competition,club):
 
 @app.route('/purchasePlaces',methods=['POST'])
 def purchasePlaces():
+    MAX_BOOKING = 12
     competition = [c for c in competitions if c['name'] == request.form['competition']][0]
     club = [c for c in clubs if c['name'] == request.form['club']][0]
     placesRequired = int(request.form['places'])
     club_points = int(club['points'])
 
     if placesRequired > club_points:
         flash("Cannot book more places than club points.")
-        return render_template('welcome.html', club=club, competitions=competitions)    
+        return render_template('welcome.html', club=club, competitions=competitions) 
+
+
+    if placesRequired > MAX_BOOKING:
+        flash(f"Cannot book more than {MAX_BOOKING} places for this competition.")
+        return render_template('welcome.html', club=club, competitions=competitions)   
 
     competition['numberOfPlaces'] = int(competition['numberOfPlaces']) - placesRequired
     flash('Great - booking complete!')

tests/unit/test_book_more_than_12_places.py

@@ -0,0 +1,47 @@
+import server
+
+"""
+Unit test file to check that clubs cannot book more than 12 places.
+
+Test 1: Club A has 13 points and competition 1 has 25 places.
+    - Book 12 places
+    - status code 200
+    - message: "Great - booking complete!"
+    - competition places decreased
+
+Test 2: Club A has 13 points and competition 1 has 25 places.
+    - Book 13 places
+    - status code 200
+    - message contains "Cannot book more than"
+    - competition places unchanged
+"""
+
+
+def test_book_12_places_allowed(client):
+    server.clubs = [{"name": "Club A", "points": "13"}]
+    server.competitions = [{"name": "Comp 1", "numberOfPlaces": "25"}]
+
+    response = client.post('/purchasePlaces', data={
+        'competition': 'Comp 1',
+        'club': 'Club A',
+        'places': '12'
+    })
+
+    assert response.status_code == 200
+    assert b"Great - booking complete!" in response.data
+    assert int(server.competitions[0]['numberOfPlaces']) == 13
+
+
+def test_cannot_book_more_than_12_places(client):
+    server.clubs = [{"name": "Club A", "points": "13"}]
+    server.competitions = [{"name": "Comp 1", "numberOfPlaces": "25"}]
+
+    response = client.post('/purchasePlaces', data={
+        'competition': 'Comp 1',
+        'club': 'Club A',
+        'places': '13'
+    })
+
+    assert response.status_code == 200
+    assert b"Cannot book more than" in response.data
+    assert int(server.competitions[0]['numberOfPlaces']) == 25