Git Patch - Rename Plus Edits at similarity index 68%

From ea95802ea6e8a65709717da7c36890ee2f600461 Mon Sep 17 00:00:00 2001
From: Ada Fernsby <ada.fernsby@example.invalid>
Date: Fri, 6 Mar 2026 10:12:40 +0000
Subject: [PATCH] refactor(ledger): rename apply.go to posting.go

Matches the package vocabulary used everywhere else.
---
 internal/ledger/{apply.go => posting.go} | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
 rename internal/ledger/{apply.go => posting.go} (68%)

diff --git a/internal/ledger/apply.go b/internal/ledger/posting.go
similarity index 68%
rename from internal/ledger/apply.go
rename to internal/ledger/posting.go
index 95f499d..ce501c6 100644
--- a/internal/ledger/apply.go
+++ b/internal/ledger/posting.go
@@ -1,14 +1,21 @@
 package ledger
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+)
 
 // ErrShortBalance is returned when a posting would drive the balance negative.
 var ErrShortBalance = errors.New("ledger: insufficient balance")
 
 // Apply posts one delta against the running balance and returns the new total.
+// A zero delta is a no-op and never reports an error.
 func Apply(balance, delta int64) (int64, error) {
+	if delta == 0 {
+		return balance, nil
+	}
 	if balance+delta < 0 {
-		return balance, ErrShortBalance
+		return balance, fmt.Errorf("%w: balance %d, requested %d", ErrShortBalance, balance, delta)
 	}
 	return balance + delta, nil
 }
-- 
2.43.0