Fixes for deprecations in Django 3.2:

- Replace use of deprecated `request.is_ajax()` with equivalent.
- Replace use of `imp.reload` with `importlib.reload`

src/oscar/apps/basket/views.py

@@ -186,7 +186,7 @@ class BasketView(ModelFormSetView):
             response = super().formset_valid(formset)
 
         # If AJAX submission, don't redirect but reload the basket content HTML
-        if self.request.is_ajax():
+        if self.request.headers.get('x-requested-with') == 'XMLHttpRequest':
             # Reload basket and apply offers again
             self.request.basket = get_model('basket', 'Basket').objects.get(
                 id=self.request.basket.id)
@@ -247,7 +247,7 @@ class BasketView(ModelFormSetView):
             "Your basket has got some issues. "
             "Please correct any validation errors below."))
 
-        if self.request.is_ajax():
+        if self.request.headers.get('x-requested-with') == 'XMLHttpRequest':
             ctx = self.get_context_data(formset=formset,
                                         basket=self.request.basket)
             return self.json_response(ctx, flash_messages)

tests/functional/checkout/test_guest_checkout.py

@@ -1,7 +1,6 @@
 import sys
 from http import client as http_client
-from imp import reload
-from importlib import import_module
+from importlib import import_module, reload
 from unittest import mock
 from urllib.parse import quote
 

tests/settings.py

@@ -169,7 +169,7 @@ OSCAR_INITIAL_LINE_STATUS = 'a'
 OSCAR_LINE_STATUS_PIPELINE = {'a': ('b', ), 'b': ()}
 
 SECRET_KEY = 'notverysecret'
-# Deprecated in Django 4.0, then we need to update the hashes to SHA-256 in tests/integration/order/test_models.py
+# Removed in Django 4.0, then we need to update the hashes to SHA-256 in tests/integration/order/test_models.py
 DEFAULT_HASHING_ALGORITHM = 'sha1'
 TEST_RUNNER = 'django.test.runner.DiscoverRunner'
 FIXTURE_DIRS = [location('unit/fixtures')]