* Update middleware.py

Show warning only if merged baskets had  items, including the total number of items that have been merged.

* fix removed Tab

* pylint

* fix line wrap

* line wrap

* fix comment too long

* comment too long

* Fix message

* use f-string

* # pylint: disable=protected-access

* still don't know what py_lint wants me to correct...

* pylint: disable=unused-argument

* make black

* f-String replaced

* added test

* TestCase with get_messages

* set request.basket

* use middleware.get_basket()

* add product to cookie basket

* make black

* empty Basket

* post to "/"

* authenticate via EmailBackend

* make black

* basket from RequestFactory

* request.basket after middleware call

* factories.create_basket()

* fix imports

* message from context

* fix import

* WebTest

* make black

* WebTestCase

* fix white space

* WebTest again

* no assertIsRedirect member

* moved test to functional

* fix import

* set cookie

* BasketView.as_view()

* get("/")

* fix AssertionError

* use WebTestCase.get()

* make black

* RequestFactory again

* call middleware

* messages from response.context

* fix tipo

* get response from Client

* get response from Client

* use User model

* fix User creation

* fix get messages from context

* refactored

* make black!

* add product with post()

* fix tipo

* save basket

* check cookie key from response

* make black

* get further

* get cookie_basket

* do not follow

* fix whitespace

* make black

* no assertIsRedirect in TestCase

* WebTestCase again

* make black

* fix product

* check message 2

* check frirst message

* new strategy

* cookie_basket.num_items

* make black

* check message 2

* check message 3

* check message 3

* make black

* response.test_app

* self.app.get

* no follow in WebTestApp

* get_essages

* initialize client

* sseparate Test class

* check cookie

* make black

* no unquote

* check context

* follow

* post add to basket

* no RequestFactory

* save cookie in session

* fix product

* set client cookie

* check 2nd message

* set cookie in session

* follow again

* check message 2

* RequestFactory in between

* user

* request up

* check basket content

* login later

* WebTestCase again

* submit again

* get message from response cookies

* don't follow

* removed unused cookie

* test basket

* get basket

* TestCase again

* make black

* "oscar_open_basket"

* don't follow

* check messages from response.context

* message format

* define user in setUp

* pluralized merged basket message

* update message

* lint

---------

Co-authored-by: Samar Hassan <samarhassanphone@gmail.com>