Creating increase / decrease quantity views functions :

** this code depends on suppliers.html code which hasn't been merged yes once the code is merged i will change it **
two functions has been created : which increase and decrease the quantity of a product by it's supplier
 *** modifie the code so it increase / decrease the quantity by "n" not one

buy_together/urls.py

@@ -23,4 +23,5 @@
     path('products/', include('product.urls')),
     path('suppliers/', include('supplier.urls')),
     path('supplier_product/', include('supplier_product.urls', namespace='supplier_product')),
+
 ]

supplier_product/test_views.py

@@ -1,39 +1,26 @@
-from django.test import TestCase, Client
+from django.test import Client
 from django.urls import reverse
-from .models import SupplierProduct, Product, Supplier
-from django.contrib.auth.models import User
+from .models import SupplierProduct
 import pytest
 
 
 @pytest.mark.django_db()
-class IncreaseQuantityTest(TestCase):
-    def setUp(self):
-        # Create a test client
-        self.client = Client()
-        # Create a test user
-        self.user = User.objects.create_user(username='testuser', password='testpassword')
-        self.supplier = Supplier.objects.create(supplier_account=self.user)
-        self.product = Product.objects.create(product_name='product1')
-        self.supplier_product = SupplierProduct.objects.create(
-            supplier_product_id=1,
-            qr_code=self.product,
-            user_name=self.supplier,
-            price=100,
-            quantity=10
-        )
+def test_increase_quantity(saved_supplier_product0):
+    supplier_product = saved_supplier_product0
+    client = Client()
+    n=3
+    response = client.get(reverse('supplier_product:increase_quantity', kwargs={'id': supplier_product.supplier_product_id, 'n': n}))
+    updated_product = SupplierProduct.objects.get(supplier_product_id=supplier_product.supplier_product_id)
+    assert updated_product.quantity == supplier_product.quantity + n
+    assert response.status_code == 302
 
-    def increase_quantity_by_one(self):
-        response = self.client.get(
-            reverse(
-                'supplier_product:increase_quantity_by_one', kwargs={'id': self.supplier_product.supplier_product_id}))
-        updated_product = SupplierProduct.objects.get(supplier_product_id=self.supplier_product.supplier_product_id)
-        self.assertEqual(updated_product.quantity, self.supplier_product.quantity + 1)
-        self.assertEqual(response.status_code, 302)
+@pytest.mark.django_db()
+def test_decrease_quantity(saved_supplier_product0):
+    supplier_product = saved_supplier_product0
+    client = Client()
+    n = 3
+    response = client.get(reverse('supplier_product:decrease_quantity', kwargs={'id': supplier_product.supplier_product_id, 'n': n}))
+    updated_product = SupplierProduct.objects.get(supplier_product_id=supplier_product.supplier_product_id)
+    assert updated_product.quantity == supplier_product.quantity - n
+    assert response.status_code == 302
 
-    def decrease_quantity_by_one(self):
-        response = self.client.get(
-            reverse(
-                'supplier_product:decrease_quantity_by_one', kwargs={'id': self.supplier_product.supplier_product_id}))
-        updated_product = SupplierProduct.objects.get(supplier_product_id=self.supplier_product.supplier_product_id)
-        self.assertEqual(updated_product.quantity, self.supplier_product.quantity - 1)
-        self.assertEqual(response.status_code, 302)

supplier_product/urls.py

@@ -4,6 +4,6 @@
 
 app_name = 'supplier_product'
 urlpatterns = [
-    path('increase_quantity_by_one/<int:id>/', views.increase_quantity, name='increase_quantity'),
-    path('decrease_quantity_by_one/<int:id>/', views.decrease_quantity, name='decrease_quantity'),
+    path('increase_quantity/<int:id>/<int:n>/', views.increase_quantity, name='increase_quantity'),
+    path('decrease_quantity/<int:id>/<int:n>/', views.decrease_quantity, name='decrease_quantity'),
 ]

supplier_product/views.py

@@ -5,31 +5,37 @@
 from django.db.models import F
 
 
-def increase_quantity_by_one(request, id):
-    SupplierProduct.objects.filter(supplier_product_id=id).update(quantity=F('quantity')+1)
-    product = SupplierProduct.objects.get(supplier_product_id=id)
+def increase_quantity(request, id, n):
+    SupplierProduct.objects.filter(supplier_product_id=id).update(quantity=F('quantity')+n)
+    try:
+        product = SupplierProduct.objects.get(supplier_product_id=id)
+    except SupplierProduct.DoesNotExist:
+    # Handle the exception here, such as returning a 404 error or redirecting to another page
+        raise HttpResponse("Product does not exist")
     context = {'product': product}
     try:
         return redirect(request.META.get('HTTP_REFERER', '/'), context)
     except TemplateDoesNotExist as e:
-        print(f'Template not found: {e}')
         return HttpResponse("Template not found")
 
 
-def decrease_quantity_by_one(request, id):
-    product = SupplierProduct.objects.get(supplier_product_id=id)
-    if product.quantity > 0:
-        SupplierProduct.objects.filter(supplier_product_id=id).update(quantity=F('quantity')-1)
+def decrease_quantity(request, id, n):
+    try:
+        product = SupplierProduct.objects.get(supplier_product_id=id)
+    except SupplierProduct.DoesNotExist:
+        raise HttpResponse("Product does not exist")
+    context = {'product': product}
+    if product.quantity > n:
+        SupplierProduct.objects.filter(supplier_product_id=id).update(quantity=F('quantity')-n)
     else:
         try:
             context = {'product': product}
             return redirect(request.META.get('HTTP_REFERER', '/'), context)
         except TemplateDoesNotExist as e:
-            print(f'Template not found: {e}')
             return HttpResponse("Template not found")
     try:
         context = {'product': product}
         return redirect(request.META.get('HTTP_REFERER', '/'), context)
     except TemplateDoesNotExist as e:
-        print(f'Template not found: {e}')
         return HttpResponse("Template not found")
+