init new frontend

frontend/src/lib/utils/format.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest';
+import { formatBytes } from './format';
+
+describe('formatBytes', () => {
+	it('formats zero', () => {
+		expect(formatBytes(0)).toBe('0 B');
+	});
+
+	it('formats bytes without decimals', () => {
+		expect(formatBytes(512)).toBe('512 B');
+	});
+
+	it('formats kilobytes and megabytes', () => {
+		expect(formatBytes(1024)).toBe('1.0 KB');
+		expect(formatBytes(1536)).toBe('1.5 KB');
+		expect(formatBytes(5 * 1024 * 1024)).toBe('5.0 MB');
+	});
+
+	it('handles invalid input', () => {
+		expect(formatBytes(-1)).toBe('—');
+		expect(formatBytes(NaN)).toBe('—');
+	});
+});