def test_expensebeforelastTrade():
t = Trades()
t.buy(Trade(0.0, 1, "S", 1.0))
t.buy(Trade(1.0, 1, "S", 1.0))
assert 1.0 == t.expense(0.1)
def test_buyOne_expenseIsOne():
t = Trades()
t.buy(Trade(0.0, 1, "S", 1.0))
assert 1.0 == t.expense(0.1)
def test_buyTwodifferent_expenseTwo():
t = Trades()
t.buy(Trade(0.0, 1, "S", 1.0))
t.buy(Trade(0.0, 1, "D", 1.0))
assert 2.0 == t.expense(1)
def test_buyOnesellOne_sameDate():
t = Trades()
t.buy(Trade(0.0, 1, "S", 1.0))
t.sell(Trade(0.0, -1, "S", 1.0))
assert 0.0 == t.expense(1) + t.revenue(1)
def test_buyOneSellOne_expenseIsOne():
t = Trades()
t.buy(Trade(0.0, 1, "S", 1.0))
t.sell(Trade(1.0, -1, "S", 1.0))
assert 1.0 == t.expense(2)
def test_buyOne_expenseIsZeroBeforeBuy():
t = Trades()
t.buy(Trade(0.0, 1, "S", 1.0))
assert 0.0 == t.expense(date=-1)
