def test_cash_flow_filter_example_simple_predicate(self, transactions):
assume(all(not math.isnan(t.value) for t in transactions))
assume(all(transaction.value > 0 for transaction in transactions))
cf = cashflow.CashFlow(transactions=transactions)
assert len(cf.filter(lambda t: t.value > 0)) == len(transactions)
def test_net_value(self, transactions):
assume(all(not math.isnan(t.value) for t in transactions))
cf = cashflow.CashFlow(transactions=transactions)
self.assertAlmostEqual(
cf.net_value, sum(t.value for t in transactions)
)
def test_create_an_empty_cashflow(self):
cf = cashflow.CashFlow()
assert len(cf) == 0
assert list(cf.transactions) == []
assert cf.net_value == decimal.Decimal(0)
def test_seriaize_cash_flow(self, transactions):
cf = cashflow.CashFlow(transactions=transactions)
expected_data = {'cashflow': [t.serialize() for t in transactions]}
self.assertDictEqual(cf.serialize(), expected_data)
self.assertEqual(
serialize_utils.json_dumps(cf.serialize()),
serialize_utils.json_dumps(expected_data)
)
def test_append_duplicate_transaction(self, transaction):
cf = cashflow.CashFlow()
cf.append(transaction)
with pytest.raises(ValueError) as cm:
cf.append(transaction)
expected_message = (
'{} already added to the cash flow'.format(repr(transaction))
)
assert str(cm.value) == expected_message
def test_cash_flow_with_one_transaction(self, transaction):
assume(not math.isnan(transaction.value))
cf = cashflow.CashFlow()
cf.append(transaction)
assert len(cf) == 1
assert tuple(cf.transactions) == (transaction, )
self.assertAlmostEqual(
cf.net_value, sum(t.value for t in (transaction,))
)
def test_dunder_getitem(self, transactions):
cf = cashflow.CashFlow()
with pytest.raises(IndexError):
cf[0]
assert len(cf[0:100]) == 0
for transaction in transactions:
cf.append(transaction)
assert tuple(cf[0].transactions)[0] == transactions[0]
assert tuple(cf[0:5].transactions) == transactions[0:5]
assert len(tuple(cf[0:5].transactions)) == len(transactions[0:5])
assert tuple(cf[::-1].transactions) == tuple(reversed(transactions))
assert len(tuple(cf[::-1].transactions)) == len(transactions[::-1])
def test_cash_flow_filter_composition(self, transactions):
assume(all(not math.isnan(t.value) for t in transactions))
assume(all(0 < t.value <= 100 for t in transactions))
cf = cashflow.CashFlow(transactions=transactions).filter(
lambda t: t.value > 0
)
assert len(cf) == len(transactions)
# Duplicate the filter to ensure the value keeps the same
cf = cf.filter(lambda t: t.value > 0).filter(lambda t: t.value > 0)
assert len(cf) == len(transactions)
cf = cf.filter(lambda t: t.value == 100)
transactions_values_greater_than_100 = tuple(
t for t in transactions if t.value == 100
)
assert tuple(cf.transactions) == transactions_values_greater_than_100
def test_dunder_contains(self, transactions):
cf = cashflow.CashFlow(transactions=transactions)
self.assertIn(transactions[0], cf)
def test_dunder_iter(self, transactions):
cf = cashflow.CashFlow(transactions=transactions)
for transaction in cf:
assert transaction in transactions
def test_dunder_len(self, transactions):
cf = cashflow.CashFlow(transactions=transactions)
assert len(cf) == len(transactions)