feat(federation): shared epoch types + getInstanceId()

packages/server/src/utils/federationEpoch.test.ts

@@ -0,0 +1,84 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import Database from 'better-sqlite3';
+import { drizzle } from 'drizzle-orm/better-sqlite3';
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import * as schema from '../db/schema.js';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+let sqlite: Database.Database;
+let testDb: ReturnType<typeof drizzle<typeof schema>>;
+
+vi.mock('../db/index.js', () => ({
+  getDb: () => testDb,
+  getRawDb: () => sqlite,
+  schema,
+}));
+
+function applyMigrations(db: Database.Database): void {
+  const dir = path.resolve(__dirname, '../../drizzle');
+  for (const f of fs.readdirSync(dir).filter(f => f.endsWith('.sql')).sort()) {
+    const sqlText = fs.readFileSync(path.join(dir, f), 'utf8');
+    for (const stmt of sqlText.split(/-->\s*statement-breakpoint/)) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+function seedEpoch(instanceId: string): void {
+  testDb.insert(schema.instanceSettings).values({
+    id: 1,
+    instanceId,
+    updatedAt: Date.now(),
+  } as typeof schema.instanceSettings.$inferInsert).run();
+}
+
+beforeEach(async () => {
+  sqlite = new Database(':memory:');
+  testDb = drizzle(sqlite, { schema });
+  applyMigrations(sqlite);
+  const { __resetInstanceIdCacheForTest } = await import('./federationEpoch.js');
+  __resetInstanceIdCacheForTest();
+});
+
+describe('getInstanceId', () => {
+  it('returns the persisted epoch', async () => {
+    seedEpoch('123e4567-e89b-12d3-a456-426614174000');
+    const { getInstanceId } = await import('./federationEpoch.js');
+    const id = getInstanceId();
+    expect(id).toBe('123e4567-e89b-12d3-a456-426614174000');
+    expect(id).toMatch(/^[0-9a-f-]{36}$/);
+  });
+
+  it('caches the value after the first read', async () => {
+    seedEpoch('123e4567-e89b-12d3-a456-426614174000');
+    const { getInstanceId } = await import('./federationEpoch.js');
+    expect(getInstanceId()).toBe('123e4567-e89b-12d3-a456-426614174000');
+
+    // Mutate the underlying row; a cached reader must NOT observe the change.
+    testDb.update(schema.instanceSettings)
+      .set({ instanceId: 'ffffffff-ffff-ffff-ffff-ffffffffffff' })
+      .run();
+    expect(getInstanceId()).toBe('123e4567-e89b-12d3-a456-426614174000');
+  });
+
+  it('re-reads after __resetInstanceIdCacheForTest clears the cache', async () => {
+    seedEpoch('123e4567-e89b-12d3-a456-426614174000');
+    const { getInstanceId, __resetInstanceIdCacheForTest } = await import('./federationEpoch.js');
+    expect(getInstanceId()).toBe('123e4567-e89b-12d3-a456-426614174000');
+
+    testDb.update(schema.instanceSettings)
+      .set({ instanceId: 'ffffffff-ffff-ffff-ffff-ffffffffffff' })
+      .run();
+    __resetInstanceIdCacheForTest();
+    expect(getInstanceId()).toBe('ffffffff-ffff-ffff-ffff-ffffffffffff');
+  });
+
+  it('throws when the epoch is unset (invariant: ensureDefaults must run first)', async () => {
+    // No row seeded — instance_settings is empty.
+    const { getInstanceId } = await import('./federationEpoch.js');
+    expect(() => getInstanceId()).toThrow(/instance_id is not set/);
+  });
+});

packages/server/src/utils/federationEpoch.ts

@@ -0,0 +1,24 @@
+import { eq } from 'drizzle-orm';
+import { getDb, schema } from '../db/index.js';
+
+let cached: string | null = null;
+
+/** This instance's persistent epoch (incarnation UUID). Set by ensureDefaults on boot. */
+export function getInstanceId(): string {
+  if (cached) return cached;
+  const db = getDb();
+  const row = db.select({ instanceId: schema.instanceSettings.instanceId })
+    .from(schema.instanceSettings)
+    .where(eq(schema.instanceSettings.id, 1))
+    .get();
+  if (!row?.instanceId) {
+    throw new Error('instance_id is not set — ensureDefaults must run before getInstanceId');
+  }
+  cached = row.instanceId;
+  return cached;
+}
+
+/** Test-only: clear the module cache between cases. */
+export function __resetInstanceIdCacheForTest(): void {
+  cached = null;
+}