FIX - polish banking interactions and transaction details

frontend/src/utils/bankingAmount.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest'
+
+import {
+  normalizeBankingAmountInput,
+  parseBankingAmount,
+} from '@/utils/bankingAmount'
+
+describe('banking amount input', () => {
+  it('uses a decimal comma and strips native number-input noise', () => {
+    expect(normalizeBankingAmountInput('1.')).toBe('1,')
+    expect(normalizeBankingAmountInput('12.00')).toBe('12,00')
+    expect(normalizeBankingAmountInput('EUR 12,00')).toBe('12,00')
+    expect(normalizeBankingAmountInput('12,0,0')).toBe('12,00')
+  })
+
+  it('keeps the server-authoritative whole-money contract', () => {
+    expect(parseBankingAmount('125')).toBe(125)
+    expect(parseBankingAmount('125,00')).toBe(125)
+    expect(parseBankingAmount('125,50')).toBeNull()
+    expect(parseBankingAmount('0')).toBeNull()
+    expect(parseBankingAmount('')).toBeNull()
+  })
+})

frontend/src/utils/bankingAmount.ts

@@ -0,0 +1,24 @@
+export function normalizeBankingAmountInput(value: string): string {
+  const normalizedSeparators = value.replace(/\./g, ',')
+  const digitsAndSeparators = normalizedSeparators.replace(/[^\d,]/g, '')
+  const separatorIndex = digitsAndSeparators.indexOf(',')
+
+  if (separatorIndex < 0) return digitsAndSeparators
+
+  const whole = digitsAndSeparators.slice(0, separatorIndex)
+  const decimal = digitsAndSeparators
+    .slice(separatorIndex + 1)
+    .replace(/,/g, '')
+    .slice(0, 2)
+
+  return `${whole},${decimal}`
+}
+
+export function parseBankingAmount(value: string): number | null {
+  if (!/^\d+(?:,\d{1,2})?$/.test(value)) return null
+
+  const amount = Number(value.replace(',', '.'))
+  if (!Number.isSafeInteger(amount) || amount <= 0) return null
+
+  return amount
+}