chain function must not corrupt the argument

[epogrebnyak]

abacus/x/test_compose.py

Lines 141 to 147 in 1bd402b

	def test_chain_must_not_corrupt_the_argument(chart_list, ledger0):
	_, _ = chain(
	chart_list, ledger0, [close_first, close_second, close_last]
	)
	assert ledger0.data["salaries"].debit_and_credit() == (2001, 0)
	assert ledger0.data["sales"].debit_and_credit() == (0, 3499)
	assert ledger0.data["refunds"].debit_and_credit() == (499, 0)

Here is how chain() works:

abacus/x/compose.py

Lines 389 to 397 in 1bd402b

	def chain(chart, ledger, functions):
	# this line is expected to make deep copy of ledger instance
	# apparently this does not work
	_ledger = ledger.condense() # .deep_copy()
	closing_entries = []
	for f in functions:
	_ledger, entries = f(chart, _ledger)
	closing_entries += entries
	return _ledger, closing_entries

I tried both ledger.condense() and ledger.deepcopy() none of them create a copy of ledger as expected.

The expected bevaviout is that after running the chain function the ledger argument is not changed!

[epogrebnyak]

The example can eb run at https://github.com/epogrebnyak/abacus/blob/main/x/using.py