From a10dbc2a0c7866f01bf61678e0e57b81592bb7ad Mon Sep 17 00:00:00 2001
From: Wojciech Maj <kontakt@wojtekmaj.pl>
Date: Wed, 18 Feb 2026 12:27:06 +0100
Subject: [PATCH] Fix kB/KiB confusion

- kB / MB means decimal units: 1000, 1,000,000.
- KiB / MiB means binary units: 1024, 1,048,576.

We were calculating binary units while labeling them as decimal ones.
---
 app/composables/useNumberFormatter.ts         | 10 ++--
 .../composables/use-number-formatter.spec.ts  | 46 +++++++++++++++++++
 2 files changed, 52 insertions(+), 4 deletions(-)
 create mode 100644 test/unit/app/composables/use-number-formatter.spec.ts

diff --git a/app/composables/useNumberFormatter.ts b/app/composables/useNumberFormatter.ts
index 0c9b46f6d..a375bc043 100644
--- a/app/composables/useNumberFormatter.ts
+++ b/app/composables/useNumberFormatter.ts
@@ -16,19 +16,21 @@ export const useBytesFormatter = () => {
   const decimalNumberFormatter = useNumberFormatter({
     maximumFractionDigits: 1,
   })
+  const KB = 1000
+  const MB = 1000 * 1000
 
   return {
     format: (bytes: number) => {
-      if (bytes < 1024)
+      if (bytes < KB)
         return t('package.size.b', {
           size: decimalNumberFormatter.value.format(bytes),
         })
-      if (bytes < 1024 * 1024)
+      if (bytes < MB)
         return t('package.size.kb', {
-          size: decimalNumberFormatter.value.format(bytes / 1024),
+          size: decimalNumberFormatter.value.format(bytes / KB),
         })
       return t('package.size.mb', {
-        size: decimalNumberFormatter.value.format(bytes / (1024 * 1024)),
+        size: decimalNumberFormatter.value.format(bytes / MB),
       })
     },
   }
diff --git a/test/unit/app/composables/use-number-formatter.spec.ts b/test/unit/app/composables/use-number-formatter.spec.ts
new file mode 100644
index 000000000..eef5d0f02
--- /dev/null
+++ b/test/unit/app/composables/use-number-formatter.spec.ts
@@ -0,0 +1,46 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { computed, ref } from 'vue'
+import { useBytesFormatter } from '../../../../app/composables/useNumberFormatter'
+
+describe('useBytesFormatter', () => {
+  beforeEach(() => {
+    vi.stubGlobal('computed', computed)
+    vi.stubGlobal('useI18n', () => ({
+      locale: ref('en-US'),
+      t: (key: string, params?: { size?: string }) => {
+        const size = params?.size ?? ''
+
+        if (key === 'package.size.b') return `${size} B`
+        if (key === 'package.size.kb') return `${size} kB`
+        if (key === 'package.size.mb') return `${size} MB`
+
+        return key
+      },
+    }))
+  })
+
+  afterEach(() => {
+    vi.unstubAllGlobals()
+  })
+
+  it('formats values below 1 kB in bytes', () => {
+    const { format } = useBytesFormatter()
+
+    expect(format(0)).toBe('0 B')
+    expect(format(999)).toBe('999 B')
+  })
+
+  it('formats kB values using decimal base (1000)', () => {
+    const { format } = useBytesFormatter()
+
+    expect(format(1000)).toBe('1 kB')
+    expect(format(8414)).toBe('8.4 kB')
+  })
+
+  it('formats MB values using decimal base (1000 * 1000)', () => {
+    const { format } = useBytesFormatter()
+
+    expect(format(1_000_000)).toBe('1 MB')
+    expect(format(1_500_000)).toBe('1.5 MB')
+  })
+})