reconcile.helper: Check file specified with --beancount-file exists

conservancy_beancount/reconcile/helper.py

@@ -20,6 +20,7 @@ from dateutil.relativedelta import relativedelta
 import datetime
 import decimal
 import io
+import sys
 import tempfile
 import textwrap
 import typing
@@ -113,7 +114,7 @@ def reconciliation_report_path(account, end_date):
     return f'Financial/Controls/Reports-for-Treasurer/{end_date}_{account_name}_bank-reconciliation.csv'
 
 
-# Parse all the arguments
+def parse_args():
     parser = argparse.ArgumentParser(description='Reconciliation helper')
     parser.add_argument('--beancount-file', required=True)
     parser.add_argument('--account', help='Full account name, e.g. "Liabilities:CreditCard:AMEX"', required=True)
@@ -129,13 +130,25 @@ args = parser.parse_args()
     if args.month or args.period:
         if not (args.month and args.period):
             parser.error('--month and --period must be used together')
+    else:
+        if not (args.cur_end_date and args.prev_end_date):
+            parser.error(' --prev-end-date and --cur-end-date must be used together')
+    return args
+
+
+def beancount_file_exists(path):
+    return os.path.isfile(path)
+
+
+args = parse_args()
+if not beancount_file_exists(args.beancount_file):
+    sys.exit(f'Beancount file does not exist: {args.beancount_file}')
+if args.month or args.period:
     parsed_date = datetime.datetime.strptime(args.month, '%Y-%m').date()
     preDate = end_of_month(parsed_date - relativedelta(months=args.period)).isoformat()
     lastDateInPeriod = end_of_month(parsed_date).isoformat()
     month = args.month
 else:
-    if not (args.cur_end_date and args.prev_end_date):
-        parser.error(' --prev-end-date and --cur-end-date must be used together')
     preDate = args.prev_end_date
     lastDateInPeriod = args.cur_end_date.isoformat()
     month = args.cur_end_date.strftime('%Y-%m')