Generate balance assignments for padding entries

While ledger has no concept of "padding", it has balance assignments
and we can convert the automatically generated padding entries (P)
to balance assignments.

Fixes #33

beancount2ledger/common.py

@@ -243,3 +243,19 @@ def map_currency(match):
     string = re.sub(rf'(?<=\d\s)(")?({amount.CURRENCY_RE})\1?', map_currency, string)
 
     return string
+
+
+def gen_bal_assignment(entry, amt, indent):
+    """
+    Generate a balance assignment
+    """
+
+    string = f"{entry.date:%Y-%m-%d}"
+    src_acct = entry.postings[0].account
+    string += f" Setting account {src_acct} to {amt}\n"
+    amt = f"= {amt}"
+    len_amt = max(0, 25 - len(indent))
+    string += f"{indent}{src_acct:50}{amt:>{len_amt}}\n"
+    dest_acct = entry.postings[1].account
+    string += f"{indent}{dest_acct}"
+    return string

beancount2ledger/hledger.py

@@ -9,6 +9,7 @@
 __license__ = "GPL-2.0-or-later"
 
 import datetime
+import re
 
 from beancount.core.amount import Amount
 from beancount.core import position
@@ -17,7 +18,7 @@
 
 from .common import ROUNDING_ACCOUNT
 from .common import ledger_flag, ledger_str, quote_currency, user_meta
-from .common import get_lineno, filter_rounding_postings
+from .common import gen_bal_assignment, get_lineno, filter_rounding_postings
 from .ledger import LedgerPrinter
 
 
@@ -34,6 +35,18 @@ def format_meta(self, key, val):
         return f"{key}: {val}"
 
     def Transaction(self, entry):
+        indent = " " * self.config["indent"]
+
+        if entry.flag == "P":
+            match = re.match(
+                r"\(Padding inserted for Balance of (.+) for difference",
+                entry.narration,
+            )
+            if match:
+                string = gen_bal_assignment(entry, match.group(1), indent)
+                self.io.write(string)
+                return
+
         # Insert a posting to absorb the residual if necessary. This is
         # sometimes needed because Ledger bases its balancing precision on the
         # *last* number of digits used on that currency. This is believed to be
@@ -70,8 +83,6 @@ def Transaction(self, entry):
             self.io.write(" " + payee)
         self.io.write("\n")
 
-        indent = " " * self.config["indent"]
-
         if entry.tags:
             self.io.write(indent + "; {}:\n".format(":, ".join(sorted(entry.tags))))
         if entry.links:

beancount2ledger/ledger.py

@@ -11,6 +11,7 @@
 
 import datetime
 import io
+import re
 
 from beancount.core.amount import Amount
 from beancount.core.inventory import Inventory
@@ -24,6 +25,7 @@
 from .common import ledger_flag, ledger_str, quote_currency, postings_by_type, user_meta
 from .common import (
     set_default,
+    gen_bal_assignment,
     get_lineno,
     is_automatic_posting,
     filter_rounding_postings,
@@ -80,6 +82,18 @@ def format_meta(self, key, val):
     def Transaction(self, entry):
         """Transactions"""
 
+        indent = " " * self.config["indent"]
+
+        if entry.flag == "P":
+            match = re.match(
+                r"\(Padding inserted for Balance of (.+) for difference",
+                entry.narration,
+            )
+            if match:
+                string = gen_bal_assignment(entry, match.group(1), indent)
+                self.io.write(string)
+                return
+
         # Insert a posting to absorb the residual if necessary. This is
         # sometimes needed because Ledger bases its balancing precision on the
         # *last* number of digits used on that currency. This is believed to be
@@ -116,8 +130,6 @@ def Transaction(self, entry):
             self.io.write(" " + payee)
         self.io.write("\n")
 
-        indent = " " * self.config["indent"]
-
         if entry.tags:
             self.io.write(indent + "; :{}:\n".format(":".join(sorted(entry.tags))))
         if entry.links:
@@ -255,11 +267,8 @@ def Pad(self, entry):
 
         # Note: We don't need to output these because when we're loading the
         # Beancount file explicit padding entries will be generated
-        # automatically, thus balancing the accounts. Ledger does not support
-        # automatically padding, so we can just output this as a comment.
-        self.io.write(
-            ";; Pad: {e.date:%Y-%m-%d} {e.account} {e.source_account}\n".format(e=entry)
-        )
+        # automatically.  We special-case these automatically padding
+        # entries to generate a ledger balance assignment.
 
     def Commodity(self, entry):
         "Commodity declarations" ""

tests/hledger_test.py

@@ -654,6 +654,38 @@ def test_preserve_posting_order(self, entries, _, ___):
             result,
         )
 
+    @loader.load_doc()
+    def test_pad(self, entries, _, ___):
+        """
+        2022-01-01 open Assets:US:Chase:Checking
+        2022-01-01 open Equity:Opening-Balances
+
+        2022-01-01 * "Set opening balance"
+          Assets:US:Chase:Checking    400.00 USD
+          Equity:Opening-Balances    -400.00 USD
+
+        2022-03-01 pad Assets:US:Chase:Checking Equity:Opening-Balances
+        2022-04-07 balance Assets:US:Chase:Checking 1000.00 USD
+        """
+        result = beancount2ledger.convert(entries)
+        self.assertLines(
+            r"""
+            account Assets:US:Chase:Checking
+
+            account Equity:Opening-Balances
+
+            2022-01-01 * Set opening balance
+              Assets:US:Chase:Checking                                       400.00 USD
+              Equity:Opening-Balances                                       -400.00 USD
+
+
+            2022-03-01 Setting account Assets:US:Chase:Checking to 1000.00 USD
+              Assets:US:Chase:Checking                                    = 1000.00 USD
+              Equity:Opening-Balances
+        """,
+            result,
+        )
+
     def test_example(self):
         """
         Test converted example with hledger

tests/ledger_test.py

@@ -340,19 +340,6 @@ def test_metadata_posting(self, entries, _, ___):
             result,
         )
 
-    @loader.load_doc()
-    def test_metadata_none(self, entries, _, ___):
-        """
-        2000-01-01 open Assets:Test1
-        2000-01-01 open Assets:Test2
-
-        2019-01-21 pad Assets:Test1 Assets:Test2
-        2019-01-22 balance Assets:Test1   10.00 GBP
-        """
-        # padding (P) entries don't set entry.meta or posting.meta, so
-        # convert to make sure we don't crash.
-        _ = beancount2ledger.convert(entries)
-
     @loader.load_doc()
     def test_cost_info(self, entries, _, ___):
         """
@@ -985,6 +972,38 @@ def test_preserve_posting_order(self, entries, _, ___):
             result,
         )
 
+    @loader.load_doc()
+    def test_pad(self, entries, _, ___):
+        """
+        2022-01-01 open Assets:US:Chase:Checking
+        2022-01-01 open Equity:Opening-Balances
+
+        2022-01-01 * "Set opening balance"
+          Assets:US:Chase:Checking    400.00 USD
+          Equity:Opening-Balances    -400.00 USD
+
+        2022-03-01 pad Assets:US:Chase:Checking Equity:Opening-Balances
+        2022-04-07 balance Assets:US:Chase:Checking 1000.00 USD
+        """
+        result = beancount2ledger.convert(entries)
+        self.assertLines(
+            r"""
+            account Assets:US:Chase:Checking
+
+            account Equity:Opening-Balances
+
+            2022-01-01 * Set opening balance
+              Assets:US:Chase:Checking                                       400.00 USD
+              Equity:Opening-Balances                                       -400.00 USD
+
+
+            2022-03-01 Setting account Assets:US:Chase:Checking to 1000.00 USD
+              Assets:US:Chase:Checking                                    = 1000.00 USD
+              Equity:Opening-Balances
+        """,
+            result,
+        )
+
     def test_example(self):
         with tempfile.NamedTemporaryFile(
             "w", suffix=".beancount", encoding="utf-8"