def test_optimal_total_cost_calculates_correctly():
raw_costs = get_raw_costs()
demand = get_demand()
trc = EOQ.optimal_relevant_cost(raw_costs, demand)
expected = trc + raw_costs.unit_cost * demand.quantity
actual = EOQ.optimal_total_cost(raw_costs=raw_costs, demand=demand)
assert expected == actual
def test_optimal_total_cost_with_missing_demand_raises():
with pytest.raises(ValueError):
EOQ.optimal_total_cost(raw_costs=get_raw_costs(), demand=None)