accrual: Check the consistency of accruals' cost.

conservancy_beancount/reports/accrual.py

@@ -67,6 +67,7 @@ import re
 import sys
 
 from typing import (
+    Any,
     Callable,
     Dict,
     Iterable,
@@ -328,18 +329,27 @@ class SearchTerm(NamedTuple):
             )
         return cls(key, pattern)
 
+def _consistency_check_one_thing(
+        key: MetaValue,
+        related: core.RelatedPostings,
+        get_name: str,
+        get_func: Callable[[data.Posting], Any],
+) -> Iterable[Error]:
+    values = {get_func(post) for post in related}
+    if len(values) != 1:
+        for post in related:
+            errmsg = f'inconsistent {get_name} for invoice {key}: {get_func(post)}'
+            yield Error(post.meta, errmsg, post.meta.txn)
 
 def consistency_check(groups: PostGroups) -> Iterable[Error]:
+    errfmt = 'inconsistent {} for invoice {}: {{}}'
     for key, related in groups.items():
+        yield from _consistency_check_one_thing(
+            key, related, 'cost', lambda post: post.cost,
+        )
         for checked_meta in ['contract', 'entity', 'purchase-order']:
-            meta_values = related.meta_values(checked_meta)
+            yield from _consistency_check_one_thing(
-            if len(meta_values) != 1:
+                key, related, checked_meta, lambda post: post.meta.get(checked_meta),
-                errmsg = f'inconsistent {checked_meta} for invoice {key}'
-                for post in related:
-                    yield Error(
-                        post.meta,
-                        f'{errmsg}: {post.meta.get(checked_meta)}',
-                        post.meta.txn,
             )
 
 def filter_search(postings: Iterable[data.Posting],

setup.py

@@ -5,7 +5,7 @@ from setuptools import setup
 setup(
     name='conservancy_beancount',
     description="Plugin, library, and reports for reading Conservancy's books",
-    version='1.0.8',
+    version='1.0.9',
     author='Software Freedom Conservancy',
     author_email='info@sfconservancy.org',
     license='GNU AGPLv3+',

tests/test_reports_accrual.py

@@ -250,6 +250,20 @@ def test_consistency_check_when_inconsistent(meta_key, account):
         assert actual.entry is txn
         assert actual.source.get('lineno') == exp_lineno
 
+def test_consistency_check_cost():
+    account = ACCOUNTS[0]
+    invoice = 'test-cost-invoice'
+    txn = testutil.Transaction(postings=[
+        (account, 100, 'EUR', ('1.1251', 'USD'), {'invoice': invoice, 'lineno': 1}),
+        (account, -100, 'EUR', ('1.125', 'USD'), {'invoice': invoice, 'lineno': 2}),
+    ])
+    related = core.RelatedPostings(data.Posting.from_txn(txn))
+    errors = list(accrual.consistency_check({invoice: related}))
+    for post, err in itertools.zip_longest(txn.postings, errors):
+        assert err.message == f'inconsistent cost for invoice {invoice}: {post.cost}'
+        assert err.entry is txn
+        assert err.source.get('lineno') == post.meta['lineno']
+
 def check_output(output, expect_patterns):
     output.seek(0)
     testutil.check_lines_match(iter(output), expect_patterns)