def test_buy_1_get_y_pct_off_z():
from cart import Cart, load_product_csv
from cart.discounts import buy_1_get_y_pct_off_z
products_csv = 'sample_products.csv'
products = load_product_csv(products_csv)
cart = Cart()
# add the product,price contents to fill up the cart with
# enough product to verify all spec'd discounts.
cart.add_products(products)
# should be 6 items in the cart (+1 discounts)
assert len(cart._contents) == 5
# * get 20% off a Snickers bar if you buy a Mars bar at the same time
discounts = buy_1_get_y_pct_off_z(cart.contents, 'mars bar',
discounted='snickers bar', pct_off=0.2)
# 20% of .70 (snickers bar) is discount of -0.14
assert round(discounts[0]['price'], 2) == -0.14
cart.apply_discounts(discounts)
# should be 6 items in the cart (+1 discounts)
assert len(cart._contents) == 6
receipt = cart.checkout()
# round due to floating point resolution issues (eg, might be 18.880000002)
assert receipt[-1]['id'] == 'grand_total'
assert round(receipt[-1]['price'], 2) == 7.1
# discounts...
assert receipt[-2]['id'] == 'discounts'
assert round(receipt[-2]['price'], 2) == -0.14
# total
assert receipt[-3]['id'] == 'total'
assert round(receipt[-3]['price'], 2) == 7.24
print str(cart)
def test_spec():
from cart import Cart, load_product_csv
from cart.discounts import buy_x_get_y, buy_1_get_y_pct_off_z
products_csv = 'sample_products.csv'
products = load_product_csv(products_csv)
cart = Cart()
# add the same contents several times to fill up the cart with
# enough product to verify all spec'd discounts.
cart.add_products(products)
cart.add_products(products)
cart.add_products(products)
# should be 15 items in the cart at this point
assert len(cart._contents) == 15
# discounts that should work according to spec
# * "buy one get one free" on ice cream
discounts = buy_x_get_y(cart.contents, 'snickers bar', buy=1, get=1)
# buy 1 snickers bar 0.70 and get one free at -0.70
assert round(discounts[0]['price'], 2) == -0.70
cart.apply_discounts(discounts)
# should be 16 items in the cart (+1 discount)
assert len(cart._contents) == 16
# shouldn't be possible to apply the same discount twice
assert 'snickers bar' in cart._discounts
try:
cart.apply_discounts(discounts)
except RuntimeError:
pass
else:
assert False, "shouldn't be able to apply same discount twice"
# should still be 16 items in the cart (+1 discount)
assert len(cart._contents) == 16
# * buy two punnets of strawberries, and get the third free
discounts = buy_x_get_y(cart.contents, 'strawberries', buy=2, get=1)
# buy 2 straberries at 2.00 each and get 2.00 off
assert round(discounts[0]['price'], 2) == -2.00
cart.apply_discounts(discounts)
assert 'strawberries' in cart._discounts
# should be 17 items in the cart (+2 discounts)
assert len(cart._contents) == 17
# * get 20% off a Snickers bar if you buy a Mars bar at the same time
discounts = buy_1_get_y_pct_off_z(
cart.contents, 'mars bar', discounted='snickers bar', pct_off=0.2)
try:
# should fail since we've already applied discount to 'snickers bar' in
# cart
cart.apply_discounts(discounts)
except RuntimeError:
pass
else:
assert False, ("shouldn't be able to apply multiple discounts "
"to same product type!")
# should still be 17 items in the cart (+2 discounts)
assert len(cart._contents) == 17
# we shouldn't have a receipt yet
assert cart._receipt == []
# we shouldn't have 'checkedout' yet
assert cart._checkout is False
receipt = cart.checkout()
# now we should have a receipt
assert cart._receipt is not None
# now we should have 'checkedout'
assert cart._checkout is True
# cart will hold onto the receipt and return a copy
assert cart.receipt == receipt
# round due to floating point resolution issues (eg, might be 18.880000002)
assert receipt[-1]['id'] == 'grand_total'
assert round(receipt[-1]['price'], 2) == 19.02
# discounts...
assert receipt[-2]['id'] == 'discounts'
assert round(receipt[-2]['price'], 2) == -2.7
# total
assert receipt[-3]['id'] == 'total'
assert round(receipt[-3]['price'], 2) == 21.72
try:
cart.checkout()
except RuntimeError:
pass
else:
assert False, "shouldn't be able to checkout more than once!"
print str(cart)
