diff --git a/tests/testutil.py b/tests/testutil.py
index 4d25277be26cf475e106ea6f6e7ab4c7cd614df4..2d05133f9eff9745622ebb224424b3c560829fb1 100644
--- a/tests/testutil.py
+++ b/tests/testutil.py
@@ -20,6 +20,7 @@ import re
 
 import beancount.core.amount as bc_amount
 import beancount.core.data as bc_data
+import beancount.loader as bc_loader
 
 from decimal import Decimal
 from pathlib import Path
@@ -33,6 +34,11 @@ FY_MID_DATE = datetime.date(2020, 9, 1)
 PAST_DATE = datetime.date(2000, 1, 1)
 TESTS_DIR = Path(__file__).parent
 
+def check_lines_match(lines, expect_patterns, source='output'):
+    for pattern in expect_patterns:
+        assert any(re.search(pattern, line) for line in lines), \
+            f"{pattern!r} not found in {source}"
+
 def check_post_meta(txn, *expected_meta, default=None):
     assert len(txn.postings) == len(expected_meta)
     for post, expected in zip(txn.postings, expected_meta):
@@ -180,6 +186,8 @@ class TestBooksLoader(books.Loader):
     def fy_range_string(self, from_fy=None, to_fy=None, plugins=None):
         return f'include "{self.source}"'
 
+    load_string = staticmethod(bc_loader.load_string)
+
 
 class TestConfig:
     def __init__(self, *,