Initialize cold WAL bookkeeping for subprocess snapshots

scripts/backup.ts

@@ -1,5 +1,7 @@
 import { Database } from "bun:sqlite";
 import { databasePath } from "../src/db/config";
 import { backupConfig, createBackup } from "../src/ops/backups";
-const db = new Database(databasePath, { readonly: true, strict: true });
+// SQLite needs writable WAL bookkeeping when the first snapshot opens a cold database.
+// Only snapshot SQL runs here; never create a missing source file.
+const db = new Database(databasePath, { readwrite: true, create: false, strict: true });
 try { console.log(createBackup(db, backupConfig(databasePath))); } finally { db.close(); }

scripts/scheduled-backup.ts

@@ -7,7 +7,9 @@ const config = JSON.parse(process.argv[3]) as BackupConfig;
 const latest = latestBackupTime(config);
 if (latest && Date.now() - latest < config.intervalMs) console.log(JSON.stringify({ timestamp: latest, created: false }));
 else {
-  const db = new Database(path, { readonly: true, strict: true });
+  // SQLite needs writable WAL bookkeeping when the first snapshot opens a cold database.
+  // Only snapshot SQL runs here; never create a missing source file.
+  const db = new Database(path, { readwrite: true, create: false, strict: true });
   try {
     db.exec('PRAGMA busy_timeout=5000');
     createBackup(db, config);

src/ops/backups.test.ts

@@ -1,6 +1,6 @@
 import { expect, test } from "bun:test";
 import { Database } from "bun:sqlite";
-import { mkdtempSync, mkdirSync, readdirSync, rmSync, statSync, writeFileSync } from "node:fs";
+import { existsSync, mkdtempSync, mkdirSync, readdirSync, rmSync, statSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
 import { tmpdir } from "node:os";
 import { fixture } from "../habits/test-fixture";
@@ -116,3 +116,34 @@ test('scheduled backup ticks coalesce, expose failure and recovery, and stop adm
   const disabled = startBackups('/tmp/test-only.sqlite', { ...config, enabled: false }, run);
   await disabled.ready; expect(calls).toBe(2); disabled.stop();
 });
+
+
+test('the first scheduled snapshot initializes cold WAL bookkeeping without changing source rows', async () => {
+  const directory = mkdtempSync(join(tmpdir(), 'minabot-cold-wal-'));
+  const path = join(directory, 'live.sqlite'), f = fixture(path);
+  f.sqlite.exec('PRAGMA journal_mode=DELETE'); f.close();
+  const db = new Database(path, { readwrite: true, create: false, strict: true });
+  let runner: ReturnType<typeof startBackups> | undefined;
+  try {
+    db.exec('PRAGMA journal_mode=WAL');
+    expect(existsSync(`${path}-shm`)).toBe(false);
+    runner = startBackups(db, backupConfig(path, {}));
+    await runner.ready;
+    expect(runner.state.failed).toBe(false);
+    expect(runner.state.lastSuccess).toBeGreaterThan(0);
+    expect(db.query('SELECT count(*) AS n FROM users').get()).toEqual({ n: 2 });
+    expect(db.query('SELECT count(*) AS n FROM sessions').get()).toEqual({ n: 2 });
+    expect(db.query('SELECT total_changes() AS n').get()).toEqual({ n: 0 });
+  } finally { runner?.stop(); db.close(); rmSync(directory, { recursive: true, force: true }); }
+});
+
+test('the scheduled snapshot never creates a missing source database', async () => {
+  const directory = mkdtempSync(join(tmpdir(), 'minabot-missing-source-'));
+  const path = join(directory, 'missing.sqlite');
+  const runner = startBackups(path, backupConfig(path, {}));
+  try {
+    await runner.ready;
+    expect(runner.state.failed).toBe(true);
+    expect(existsSync(path)).toBe(false);
+  } finally { runner.stop(); rmSync(directory, { recursive: true, force: true }); }
+});