API: Trust discounts assigned by pretixPOS, do not assign differently (#5531)

src/tests/api/test_order_create.py

@@ -3134,3 +3134,128 @@ def test_order_create_create_medium(token_client, organizer, event, item, quota,
         m = organizer.reusable_media.get(identifier=i)
         assert m.linked_orderposition == o.positions.first()
         assert m.type == "barcode"
+
+
+@pytest.mark.django_db
+def test_order_create_auto_pricing_discount(token_client, organizer, event, item, quota, question, taxrule):
+    with scopes_disabled():
+        event.discounts.create(
+            condition_min_count=2,
+            benefit_discount_matching_percent=50,
+            benefit_only_apply_to_cheapest_n_matches=1,
+        )
+
+    res = copy.deepcopy(ORDER_CREATE_PAYLOAD)
+    res['positions'][0]['item'] = item.pk
+    res['positions'][0]['answers'][0]['question'] = question.pk
+    del res['positions'][0]['positionid']
+    del res['positions'][0]['price']
+    res['positions'].append(dict(res['positions'][0]))
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orders/'.format(
+            organizer.slug, event.slug
+        ), format='json', data=res
+    )
+    assert resp.status_code == 201
+    with scopes_disabled():
+        o = Order.objects.get(code=resp.data['code'])
+        p1 = o.positions.first()
+        p2 = o.positions.last()
+    assert p1.price == Decimal('23')
+    assert p2.price == Decimal('11.50')
+    assert o.total == Decimal('34.75')
+
+
+@pytest.mark.django_db
+def test_order_create_auto_pricing_do_not_discount_if_price_explcitly_set(token_client, organizer, event, item, quota, question, taxrule):
+    with scopes_disabled():
+        event.discounts.create(
+            condition_min_count=2,
+            benefit_discount_matching_percent=50,
+            benefit_only_apply_to_cheapest_n_matches=1,
+        )
+
+    res = copy.deepcopy(ORDER_CREATE_PAYLOAD)
+    res['positions'][0]['item'] = item.pk
+    res['positions'][0]['answers'][0]['question'] = question.pk
+    del res['positions'][0]['positionid']
+    res['positions'].append(dict(res['positions'][0]))
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orders/'.format(
+            organizer.slug, event.slug
+        ), format='json', data=res
+    )
+    assert resp.status_code == 201
+    with scopes_disabled():
+        o = Order.objects.get(code=resp.data['code'])
+        p1 = o.positions.first()
+        p2 = o.positions.last()
+    assert p1.price == Decimal('23.00')
+    assert p2.price == Decimal('23.00')
+    assert o.total == Decimal('46.25')
+
+
+@pytest.mark.django_db
+def test_order_create_auto_pricing_believe_wrong_discounts_by_client(token_client, organizer, event, item, quota, question, taxrule):
+    with scopes_disabled():
+        discount = event.discounts.create(
+            condition_min_count=2,
+            benefit_discount_matching_percent=50,
+            benefit_only_apply_to_cheapest_n_matches=1,
+        )
+
+    res = copy.deepcopy(ORDER_CREATE_PAYLOAD)
+    res['positions'][0]['item'] = item.pk
+    res['positions'][0]['answers'][0]['question'] = question.pk
+    del res['positions'][0]['positionid']
+    res['positions'].append(dict(res['positions'][0]))
+    res['positions'][0]['price'] = Decimal("10.00")
+    res['positions'][1]['price'] = Decimal("7.00")
+    res['positions'][1]['discount'] = discount.pk
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orders/'.format(
+            organizer.slug, event.slug
+        ), format='json', data=res
+    )
+    assert resp.status_code == 201
+    with scopes_disabled():
+        o = Order.objects.get(code=resp.data['code'])
+        p1 = o.positions.first()
+        p2 = o.positions.last()
+    assert p1.price == Decimal('10.00')
+    assert p1.discount is None
+    assert p2.price == Decimal('7.00')
+    assert p2.discount == discount
+    assert o.total == Decimal('17.25')
+
+
+@pytest.mark.django_db
+def test_order_create_auto_pricing_explicit_discount_not_allowed(token_client, organizer, event, item, quota, question, taxrule):
+    with scopes_disabled():
+        discount = event.discounts.create(
+            condition_min_count=2,
+            benefit_discount_matching_percent=50,
+            benefit_only_apply_to_cheapest_n_matches=1,
+        )
+
+    res = copy.deepcopy(ORDER_CREATE_PAYLOAD)
+    res['positions'][0]['item'] = item.pk
+    res['positions'][0]['answers'][0]['question'] = question.pk
+    del res['positions'][0]['positionid']
+    del res['positions'][0]['price']
+    res['positions'].append(dict(res['positions'][0]))
+    res['positions'][1]['discount'] = discount.pk
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orders/'.format(
+            organizer.slug, event.slug
+        ), format='json', data=res
+    )
+    assert resp.status_code == 400
+    assert resp.data == {
+        "positions": [
+            {},
+            {
+                "discount": ["You can only specify a discount if you do the price computation, but price is not set."]
+            }
+        ]
+    }