fix: Disallow identical effective and actual dates

beancount_reds_plugins/effective_date/effective_date.py

@@ -7,6 +7,7 @@
 import string
 import sys
 import time
+from typing import NamedTuple
 from beancount.core import data
 from beancount_reds_plugins.common import common
 
@@ -18,6 +19,10 @@
 
 LINK_FORMAT = 'edate-{date}-{random}'
 
+class EffectiveDateError(NamedTuple):
+    source: data.Meta
+    message: str
+    entry: data.Directive
 
 def has_valid_effective_date(posting):
     return posting.meta is not None and \
@@ -31,6 +36,13 @@ def has_posting_with_valid_effective_date(entry):
             return True
     return False
 
+def has_posting_with_meaningless_effective_date(entry):
+    for posting in entry.postings:
+        if has_valid_effective_date(posting) \
+            and posting.meta['effective_date'] == entry.date:
+            return True
+    return False
+
 
 def create_new_effective_date_entry(entry, date, hold_posting, original_posting):
     def cleaned(p):
@@ -80,7 +92,17 @@ def effective_date(entries, options_map, config):
     new_accounts = set()
     for entry in entries:
         if isinstance(entry, data.Transaction) and has_posting_with_valid_effective_date(entry):
-            interesting_entries.append(entry)
+            if not has_posting_with_meaningless_effective_date(entry):
+                interesting_entries.append(entry)
+            else:
+                errors.append(
+                    EffectiveDateError(
+                        entry.meta,
+                        "Effective and actual dates are identical",
+                        entry
+                    )
+                )
+                filtered_entries.append(entry)
         else:
             filtered_entries.append(entry)
 

beancount_reds_plugins/effective_date/test_effective_date.py

@@ -142,3 +142,18 @@ def test_expense_later_multiple(self, entries, _, options_map):
 
         new_entries, _ = effective_date(entries, options_map, None)
         self.assertEqual(7, len(new_entries))
+
+    @loader.load_doc()
+    def test_meaningless_effective_dates(self, entries, _, options_map):
+        """
+        2014-01-01 open Liabilities:Mastercard
+        2014-01-01 open Expenses:Taxes:Federal
+
+        2014-02-01 * "Estimated taxes for 2013"
+          Liabilities:Mastercard    -2000 USD
+          Expenses:Taxes:Federal  2000 USD
+            effective_date: 2014-02-01
+         """
+        new_entries, errors = effective_date(entries, options_map, None)
+        self.assertEqual(1, len(errors))
+        self.assertEqual(new_entries, entries)