From 8ee4baf9ac55e2cc54c1699ecc51e7c83f6ac6b2 Mon Sep 17 00:00:00 2001
From: polskus <31725163+polskus@users.noreply.github.com>
Date: Sun, 25 Oct 2026 00:45:45 +0200
Subject: [PATCH] Correctly format negative single digit cent amounts.

Negative cent amounts from -1 to -9 were incorrectly formatted to be 0.1 and 0.9. The issue was the negative sign '-' which caused the padding to be off by one.
A test including a negative number was also added.
This completes the fix in #591.
---
 src/tests/number.test.ts | 8 +++++---
 src/utils/numbers.ts     | 7 +++++--
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/tests/number.test.ts b/src/tests/number.test.ts
index 15c14456a..7ff81fd3c 100644
--- a/src/tests/number.test.ts
+++ b/src/tests/number.test.ts
@@ -31,9 +31,11 @@ describe('getCurrencyHelpers', () => {
           expect(toUIString(value)).toBe('$1,234');
         });
 
-        it('Should correctly format single digit cent amounts', () => {
-          const value = 7n;
-          expect(toUIString(value)).toBe('$0.07');
+        it.each([
+          [7n, '$0.07'],
+          [-7n, '$0.07'],
+        ])('Should correctly format single digit cent amounts', (value, expected) => {
+          expect(toUIString(value)).toBe(expected);
         });
 
         it.each([
diff --git a/src/utils/numbers.ts b/src/utils/numbers.ts
index b39912e58..13688d747 100644
--- a/src/utils/numbers.ts
+++ b/src/utils/numbers.ts
@@ -150,8 +150,11 @@ export const getCurrencyHelpers = ({
 
     if (typeof value === 'bigint') {
       const sign = value < 0n && signed ? '-' : '';
-      const integer = `${value / decimalMultiplierN}`;
-      const fraction = `${value}`.slice(-decimalDigits).padStart(decimalDigits, '0');
+      const absValue = BigMath.abs(value);
+      const integer = `${absValue / decimalMultiplierN}`;
+      const fraction = `${absValue % decimalMultiplierN}`
+        .slice(-decimalDigits)
+        .padStart(decimalDigits, '0');
       return (
         sign +
         normalizeToMaxLength(