feat(core): export bundle, restore, backups

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

packages/core/test/backup.test.ts

@@ -0,0 +1,44 @@
+import { afterEach, beforeEach, expect, test } from "bun:test";
+import { mkdtemp, readdir, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { forEachDialect } from "@sttracker/db/testing";
+import { backupHandler, runBackup } from "../src/backup.ts";
+import { makeUser } from "./user-layer-fixtures.ts";
+
+forEachDialect("backup", (getDb) => {
+  let dir: string;
+  beforeEach(async () => {
+    dir = await mkdtemp(join(tmpdir(), "sttracker-bak-"));
+  });
+  afterEach(async () => {
+    await rm(dir, { recursive: true, force: true });
+  });
+
+  test("backup writes a bundle per user (and the db on sqlite)", async () => {
+    const db = getDb();
+    await makeUser(db, "ada");
+    await makeUser(db, "bob");
+    const out = await runBackup(db, dir, { keep: 14 });
+    expect(out.startsWith(join(dir, "backups"))).toBe(true);
+    const files = (await readdir(out)).sort();
+    expect(files).toEqual(db.dialect === "sqlite" ? ["ada.zip", "bob.zip", "sttracker.db"] : ["ada.zip", "bob.zip"]);
+  });
+
+  test("backup prunes to keep", async () => {
+    const db = getDb();
+    await makeUser(db, "ada");
+    const made: string[] = [];
+    for (let i = 0; i < 4; i++) made.push(await runBackup(db, dir, { keep: 2 }));
+    const left = (await readdir(join(dir, "backups"))).sort();
+    expect(left).toHaveLength(2);
+    expect(left.map((n) => join(dir, "backups", n))).toEqual(made.slice(2));
+  });
+
+  test("backupHandler runs a backup", async () => {
+    const db = getDb();
+    await makeUser(db, "ada");
+    await backupHandler({ db, dataDir: dir, keep: 3 })();
+    expect(await readdir(join(dir, "backups"))).toHaveLength(1);
+  });
+});