feat(backend): SQLite-Schicht mit WAL, Dokumenten und Historie

server/db.test.js

@@ -0,0 +1,29 @@
+const { test } = require('node:test');
+const assert = require('node:assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+
+// DATA_DIR auf Temp umbiegen, BEVOR db.js geladen wird
+process.env.DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), 'dp-db-'));
+const { getDoc, putDoc } = require('./db');
+
+test('putDoc/getDoc Roundtrip', () => {
+  putDoc('employees', ['Max', 'Anna'], '2026-07-07T10:00:00.000Z');
+  const doc = getDoc('employees');
+  assert.deepStrictEqual(doc.value, ['Max', 'Anna']);
+  assert.strictEqual(doc.updatedAt, '2026-07-07T10:00:00.000Z');
+});
+
+test('getDoc für unbekannten Key liefert null', () => {
+  assert.strictEqual(getDoc('gibtsnicht'), null);
+});
+
+test('putDoc snapshottet den alten Wert in history', () => {
+  const { db } = require('./db');
+  putDoc('duties', { v: 1 }, '2026-07-07T10:00:00.000Z');
+  putDoc('duties', { v: 2 }, '2026-07-07T11:00:00.000Z');
+  const rows = db.prepare("SELECT value FROM history WHERE key = 'duties' ORDER BY id").all();
+  assert.strictEqual(rows.length, 1);
+  assert.deepStrictEqual(JSON.parse(rows[0].value), { v: 1 });
+});