From 3b0e824c5b8427eb3725c953f9a41d385424d3be Mon Sep 17 00:00:00 2001
From: Sjoerd de Vries <openai@sjoerddev.com>
Date: Sat, 5 Sep 2026 15:15:09 +0200
Subject: [PATCH] feat: add daily cron scheduler for price checks

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
---
 src/scheduler.js       | 10 ++++++++++
 test/scheduler.test.js | 21 +++++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 src/scheduler.js
 create mode 100644 test/scheduler.test.js

diff --git a/src/scheduler.js b/src/scheduler.js
new file mode 100644
index 0000000..234090f
--- /dev/null
+++ b/src/scheduler.js
@@ -0,0 +1,10 @@
+const cronDefault = require('node-cron');
+
+const SCHEDULE = '0 8 * * *';
+const TIMEZONE = 'Europe/Amsterdam';
+
+function start(runCheck, { cron = cronDefault } = {}) {
+  return cron.schedule(SCHEDULE, runCheck, { timezone: TIMEZONE });
+}
+
+module.exports = { start, SCHEDULE, TIMEZONE };
diff --git a/test/scheduler.test.js b/test/scheduler.test.js
new file mode 100644
index 0000000..5d97105
--- /dev/null
+++ b/test/scheduler.test.js
@@ -0,0 +1,21 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const { start, SCHEDULE, TIMEZONE } = require('../src/scheduler');
+
+test('start schedules the daily check with the expected cron expression and timezone', () => {
+  const calls = [];
+  const fakeCron = {
+    schedule: (expression, fn, options) => {
+      calls.push({ expression, fn, options });
+      return { stop: () => {} };
+    },
+  };
+  const runCheck = async () => {};
+  start(runCheck, { cron: fakeCron });
+  assert.equal(calls.length, 1);
+  assert.equal(calls[0].expression, SCHEDULE);
+  assert.equal(SCHEDULE, '0 8 * * *');
+  assert.equal(calls[0].options.timezone, TIMEZONE);
+  assert.equal(TIMEZONE, 'Europe/Amsterdam');
+  assert.equal(calls[0].fn, runCheck);
+});