Finanzen: Vorschau, Steuer und Abos

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/unit/financeFormat.test.mjs

@@ -18,6 +18,7 @@ const {
   nextIntervalDate,
   ymdBerlin,
   INTERVAL_LABEL,
+  percentDe,
 } = await loadModule('src/lib/financeFormat.js')
 
 const MINUS = '−'
@@ -298,3 +299,20 @@ test('ymdBerlin: Berliner Kalendertag eines Zeitpunkts', () => {
   assert.equal(ymdBerlin(null), null)
   assert.equal(ymdBerlin(NaN), null)
 })
+
+test('percentDe: Dezimalkomma, überflüssige Nullen entfallen', () => {
+  assert.equal(percentDe(30), '30')
+  assert.equal(percentDe(27.5), '27,5')
+  assert.equal(percentDe(30.25), '30,25')
+  assert.equal(percentDe(0), '0')
+  assert.equal(percentDe(100), '100')
+  assert.equal(percentDe(0.32, 1), '0,3')
+  assert.equal(percentDe(70.4, 1), '70,4')
+  assert.equal(percentDe(30.256), '30,26')
+  assert.equal(percentDe(-12.5), `${MINUS}12,5`)
+  assert.equal(percentDe(-0.001), '0')
+})
+
+test('percentDe: Platzhalter für fehlende Werte', () => {
+  for (const v of [null, undefined, NaN, Infinity, 'x']) assert.equal(percentDe(v), '–')
+})