feat: 4h-Aggregation, EMA, ATR, Donchian-High (TDD)

src/server/indicators/donchian.test.ts

@@ -0,0 +1,15 @@
+import { expect, test } from 'bun:test';
+import type { Candle } from '../types';
+import { donchianHigh } from './donchian';
+
+function c(h: number): Candle {
+  return { ts: 0, open: h, high: h, low: h - 1, close: h, volume: 1 };
+}
+
+test('donchianHigh: höchstes Hoch der letzten N Candles VOR i (i exklusiv)', () => {
+  const candles = [c(10), c(12), c(11), c(9), c(15)];
+  const out = donchianHigh(candles, 3);
+  expect(out.slice(0, 3).every(Number.isNaN)).toBe(true);
+  expect(out[3]).toBe(12); // max(10,12,11)
+  expect(out[4]).toBe(12); // max(12,11,9) — Candle 4 selbst zählt nicht
+});