From 219cd4bc37a41e69d47543607664b829fd03c7a9 Mon Sep 17 00:00:00 2001 From: Brett Smith Date: Sun, 12 Apr 2020 09:47:41 -0400 Subject: [PATCH] reports.core: Start RelatedPostings class. --- conservancy_beancount/reports/__init__.py | 0 conservancy_beancount/reports/core.py | 79 ++++++++++++++++++++ tests/test_reports_related_postings.py | 87 +++++++++++++++++++++++ 3 files changed, 166 insertions(+) create mode 100644 conservancy_beancount/reports/__init__.py create mode 100644 conservancy_beancount/reports/core.py create mode 100644 tests/test_reports_related_postings.py diff --git a/conservancy_beancount/reports/__init__.py b/conservancy_beancount/reports/__init__.py new file mode 100644 index 0000000..e69de29 diff --git a/conservancy_beancount/reports/core.py b/conservancy_beancount/reports/core.py new file mode 100644 index 0000000..7c6debc --- /dev/null +++ b/conservancy_beancount/reports/core.py @@ -0,0 +1,79 @@ +"""core.py - Common data classes for reporting functionality""" +# Copyright © 2020 Brett Smith +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU Affero General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU Affero General Public License for more details. +# +# You should have received a copy of the GNU Affero General Public License +# along with this program. If not, see . + +import collections + +from decimal import Decimal + +from .. import data + +from typing import ( + overload, + Dict, + List, + Sequence, + Union, +) + +class RelatedPostings(Sequence[data.Posting]): + """Collect and query related postings + + This class provides common functionality for collecting related postings + and running queries on them: iterating over them, tallying their balance, + etc. + + This class doesn't know anything about how the postings are related. That's + entirely up to the caller. + + A common pattern is to use this class with collections.defaultdict + to organize postings based on some key:: + + report = collections.defaultdict(RelatedPostings) + for txn in transactions: + for post in Posting.from_txn(txn): + if should_report(post): + key = post_key(post) + report[key].add(post) + """ + + def __init__(self) -> None: + self._postings: List[data.Posting] = [] + + @overload + def __getitem__(self, index: int) -> data.Posting: ... + + @overload + def __getitem__(self, s: slice) -> Sequence[data.Posting]: ... + + def __getitem__(self, + index: Union[int, slice], + ) -> Union[data.Posting, Sequence[data.Posting]]: + if isinstance(index, slice): + raise NotImplementedError("RelatedPostings[slice]") + else: + return self._postings[index] + + def __len__(self) -> int: + return len(self._postings) + + def add(self, post: data.Posting) -> None: + self._postings.append(post) + + def balance(self) -> Sequence[data.Amount]: + currency_balance: Dict[str, Decimal] = collections.defaultdict(Decimal) + for post in self: + currency_balance[post.units.currency] += post.units.number + return [data.Amount(number, key) for key, number in currency_balance.items()] diff --git a/tests/test_reports_related_postings.py b/tests/test_reports_related_postings.py new file mode 100644 index 0000000..9a70d8e --- /dev/null +++ b/tests/test_reports_related_postings.py @@ -0,0 +1,87 @@ +"""test_reports_related_postings - Unit tests for RelatedPostings""" +# Copyright © 2020 Brett Smith +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU Affero General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU Affero General Public License for more details. +# +# You should have received a copy of the GNU Affero General Public License +# along with this program. If not, see . + +import datetime +import itertools + +import pytest + +from . import testutil + +from conservancy_beancount import data +from conservancy_beancount.reports import core + +_day_counter = itertools.count(1) +def next_date(): + return testutil.FY_MID_DATE + datetime.timedelta(next(_day_counter)) + +def txn_pair(acct, src_acct, dst_acct, amount, date=None, txn_meta={}, post_meta={}): + if date is None: + date = next_date() + src_txn = testutil.Transaction(date=date, **txn_meta, postings=[ + (acct, amount, post_meta.copy()), + (src_acct, -amount), + ]) + dst_date = date + datetime.timedelta(days=1) + dst_txn = testutil.Transaction(date=dst_date, **txn_meta, postings=[ + (acct, -amount, post_meta.copy()), + (dst_acct, amount), + ]) + return (src_txn, dst_txn) + +def donation(amount, currency='USD', date=None, other_acct='Assets:Cash', **meta): + if date is None: + date = next_date() + return testutil.Transaction(date=date, postings=[ + ('Income:Donations', -amount, currency, meta), + (other_acct, amount, currency), + ]) + +def test_balance(): + related = core.RelatedPostings() + related.add(data.Posting.from_beancount(donation(10), 0)) + assert related.balance() == [testutil.Amount(-10)] + related.add(data.Posting.from_beancount(donation(15), 0)) + assert related.balance() == [testutil.Amount(-25)] + related.add(data.Posting.from_beancount(donation(20), 0)) + assert related.balance() == [testutil.Amount(-45)] + +def test_balance_zero(): + related = core.RelatedPostings() + related.add(data.Posting.from_beancount(donation(10), 0)) + related.add(data.Posting.from_beancount(donation(-10), 0)) + assert related.balance() == [testutil.Amount(0)] + +def test_balance_multiple_currencies(): + related = core.RelatedPostings() + related.add(data.Posting.from_beancount(donation(10, 'GBP'), 0)) + related.add(data.Posting.from_beancount(donation(15, 'GBP'), 0)) + related.add(data.Posting.from_beancount(donation(20, 'EUR'), 0)) + related.add(data.Posting.from_beancount(donation(25, 'EUR'), 0)) + assert set(related.balance()) == { + testutil.Amount(-25, 'GBP'), + testutil.Amount(-45, 'EUR'), + } + +def test_balance_multiple_currencies_one_zero(): + related = core.RelatedPostings() + related.add(data.Posting.from_beancount(donation(10, 'EUR'), 0)) + related.add(data.Posting.from_beancount(donation(15, 'USD'), 0)) + related.add(data.Posting.from_beancount(donation(-10, 'EUR'), 0)) + assert set(related.balance()) == { + testutil.Amount(-15, 'USD'), + testutil.Amount(0, 'EUR'), + }