def test_trc_calculates_correctly():
# arrange
demand = get_demand()
raw_costs = get_raw_costs()
order_quantity = 100
# act
trc = Costs.total_relevant_cost(raw_costs=raw_costs,
demand=demand,
order_quantity=order_quantity)
# assert
ordering_cost = Costs.ordering_cost(ordering_cost=raw_costs.ordering_cost,
demand_quantity=demand.quantity,
order_quantity=order_quantity)
holding_cost = Costs.holding_cost(holding_cost=raw_costs.holding_cost,
order_quantity=order_quantity)
assert trc == ordering_cost + holding_cost
def test_tc_calculates_correctly():
# arrange
demand = get_demand()
raw_costs = get_raw_costs()
order_quantity = 100
# act
tc = Costs.total_cost(raw_costs=raw_costs,
demand=demand,
order_quantity=order_quantity)
# assert
purchase_cost = Costs.purchase_cost(unit_cost=raw_costs.unit_cost,
demand_quantity=demand.quantity)
shortage_cost = Costs.shortage_cost(shortage_cost=raw_costs.shortage_cost,
shortage_quantity=0)
trc = Costs.total_relevant_cost(raw_costs=raw_costs,
demand=demand,
order_quantity=order_quantity)
assert tc == purchase_cost + trc + shortage_cost
def test_purchase_cost_with_missing_unit_cost_raises():
with pytest.raises(ValueError):
Costs.purchase_cost(unit_cost=None, demand_quantity=1)
def test_ordering_cost_with_zero_order_quantity_raises():
with pytest.raises(ValueError):
Costs.ordering_cost(ordering_cost=1.0,
demand_quantity=1,
order_quantity=0)
def test_ordering_cost_with_negative_demand_quantity_raises():
with pytest.raises(ValueError):
Costs.ordering_cost(ordering_cost=1.0,
demand_quantity=-1,
order_quantity=1)
def test_ordering_cost_with_missing_demand_quantity_raises():
with pytest.raises(ValueError):
Costs.ordering_cost(ordering_cost=1.0,
demand_quantity=None,
order_quantity=1)
def test_purchase_cost_calculates_result():
pc = Costs.purchase_cost(unit_cost=1.25, demand_quantity=25)
assert pc == 1.25 * 25
def test_purchase_cost_with_negative_demand_quantity_raises():
with pytest.raises(ValueError):
Costs.purchase_cost(unit_cost=1.0, demand_quantity=-1)
def test_holding_cost_calculates_correctly():
hc = Costs.holding_cost(holding_cost=0.25, order_quantity=100)
assert hc == 0.25 * (100 / 2)
def test_tc_with_missing_expected_shortage_raises():
with pytest.raises(ValueError):
Costs.total_cost(raw_costs=get_raw_costs(),
demand=get_demand(),
order_quantity=100,
expected_shortage=None)
def test_tc_with_missing_order_quantity_raises():
with pytest.raises(ValueError):
Costs.total_cost(raw_costs=get_raw_costs(),
demand=get_demand(),
order_quantity=None)
def test_trc_with_missing_demand_raises():
with pytest.raises(ValueError):
Costs.total_relevant_cost(raw_costs=get_raw_costs(),
demand=None,
order_quantity=100)
def test_shortage_cost_calculates_correctly():
sc = Costs.shortage_cost(shortage_cost=2.00, shortage_quantity=125)
assert sc == 2.00 * 125
def test_shortage_cost_with_negative_shortage_quantity_raises():
with pytest.raises(ValueError):
Costs.shortage_cost(shortage_cost=1.0, shortage_quantity=-1)
def test_shortage_cost_with_missing_shortage_quantity_raises():
with pytest.raises(ValueError):
Costs.shortage_cost(shortage_cost=1.0, shortage_quantity=None)
def test_ordering_cost_calculates_correctly():
oc = Costs.ordering_cost(ordering_cost=100.0,
demand_quantity=250,
order_quantity=25)
assert oc == 100.0 * (250 / 25)
def test_holding_cost_with_missing_holding_cost_raises():
with pytest.raises(ValueError):
Costs.holding_cost(holding_cost=None, order_quantity=1)
def test_holding_cost_with_negative_order_quantity_raises():
with pytest.raises(ValueError):
Costs.holding_cost(holding_cost=1.0, order_quantity=-1)
