def test_contract_costs():
c = Contract('ticker', 'test', '')
c.long_offers = [
Offer(c, 'Yes', .1, 5),
Offer(c, 'Yes', .16, 10),
Offer(c, 'Yes', .2, 100),
]
c.short_offers = [
Offer(c, 'Yes', .4, 6),
Offer(c, 'Yes', .5, 4),
Offer(c, 'Yes', .6, 10),
]
assert c.cost_to_buy_n_long(1000) is None
assert c.cost_to_buy_n_short(1000) is None
assert c.cost_to_buy_n_long(5) == .5
assert c.cost_to_buy_n_long(10) == 1.3
assert c.cost_to_buy_n_long(20) == 3.1
assert c.cost_to_buy_n_short(6) == 2.4
assert c.cost_to_buy_n_short(10) == 4.4
assert c.cost_to_buy_n_short(12) == 5.6
assert c.cost_to_buy_n_short(20) == 10.4
