nanodrop/tests/unit/session-renewal.test.ts

import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import Fastify, { type FastifyInstance } from 'fastify';
import fastifyCookie from '@fastify/cookie';
import fastifyJwt from '@fastify/jwt';
import { slideSessionIfNeeded } from '../../src/middleware/session-renewal.ts';
import {
  SESSION_COOKIE_NAME,
  SESSION_RENEW_THRESHOLD_SECONDS,
  SESSION_TTL_SECONDS,
} from '../../src/constants.ts';

interface TestPayload {
  sub: number;
  username: string;
  iat?: number;
}

async function buildTestServer(): Promise<FastifyInstance> {
  const app = Fastify();
  await app.register(fastifyCookie);
  await app.register(fastifyJwt, {
    secret: 'test-secret',
    cookie: { cookieName: SESSION_COOKIE_NAME, signed: false },
  });
  await app.ready();
  return app;
}

const NOW_ISO = '2026-01-01T12:00:00Z';
const NOW_SEC = Math.floor(new Date(NOW_ISO).getTime() / 1000);

describe('slideSessionIfNeeded', () => {
  let app: FastifyInstance;

  beforeEach(async () => {
    vi.useFakeTimers({ toFake: ['Date'] });
    vi.setSystemTime(new Date(NOW_ISO));
    app = await buildTestServer();
  });

  afterEach(async () => {
    vi.useRealTimers();
    await app.close();
  });

  function fakeReply(): { setCookieCalls: Array<{ name: string; value: string; opts: Record<string, unknown> }> } & Record<string, unknown> {
    const setCookieCalls: Array<{ name: string; value: string; opts: Record<string, unknown> }> = [];
    return {
      setCookieCalls,
      setCookie(name: string, value: string, opts: Record<string, unknown>) {
        setCookieCalls.push({ name, value, opts });
        return this;
      },
    };
  }

  function fakeRequest(url: string): { url: string } {
    return { url };
  }

  it('re-issues cookie when now - iat >= SESSION_RENEW_THRESHOLD_SECONDS', () => {
    const reply = fakeReply();
    const payload: TestPayload = {
      sub: 1,
      username: 'alice',
      iat: NOW_SEC - SESSION_RENEW_THRESHOLD_SECONDS,
    };
    slideSessionIfNeeded(fakeRequest('/upload') as never, reply as never, payload, app, false);
    expect(reply.setCookieCalls.length).toBe(1);
    expect(reply.setCookieCalls[0].name).toBe(SESSION_COOKIE_NAME);
    expect(reply.setCookieCalls[0].opts.maxAge).toBe(SESSION_TTL_SECONDS);
  });

  it('skips re-issue when now - iat < SESSION_RENEW_THRESHOLD_SECONDS', () => {
    const reply = fakeReply();
    const payload: TestPayload = {
      sub: 1,
      username: 'alice',
      iat: NOW_SEC - (SESSION_RENEW_THRESHOLD_SECONDS - 1),
    };
    slideSessionIfNeeded(fakeRequest('/upload') as never, reply as never, payload, app, false);
    expect(reply.setCookieCalls.length).toBe(0);
  });

  it('skips re-issue on /logout path', () => {
    const reply = fakeReply();
    const payload: TestPayload = { sub: 1, username: 'alice', iat: 0 }; // ancient
    slideSessionIfNeeded(fakeRequest('/logout') as never, reply as never, payload, app, false);
    expect(reply.setCookieCalls.length).toBe(0);
  });

  it('skips re-issue on /api/v1/auth/logout path', () => {
    const reply = fakeReply();
    const payload: TestPayload = { sub: 1, username: 'alice', iat: 0 };
    slideSessionIfNeeded(fakeRequest('/api/v1/auth/logout') as never, reply as never, payload, app, false);
    expect(reply.setCookieCalls.length).toBe(0);
  });

  it('skips re-issue when /logout has a query string', () => {
    const reply = fakeReply();
    const payload: TestPayload = { sub: 1, username: 'alice', iat: 0 };
    slideSessionIfNeeded(fakeRequest('/logout?redirect=foo') as never, reply as never, payload, app, false);
    expect(reply.setCookieCalls.length).toBe(0);
  });

  it('treats missing iat as 0 (forces refresh)', () => {
    const reply = fakeReply();
    const payload: TestPayload = { sub: 1, username: 'alice' };
    slideSessionIfNeeded(fakeRequest('/upload') as never, reply as never, payload, app, false);
    expect(reply.setCookieCalls.length).toBe(1);
  });

  it('produces a cookie carrying Max-Age=SESSION_TTL_SECONDS', () => {
    const reply = fakeReply();
    const payload: TestPayload = { sub: 1, username: 'alice', iat: 0 };
    slideSessionIfNeeded(fakeRequest('/upload') as never, reply as never, payload, app, true);
    expect(reply.setCookieCalls[0].opts.maxAge).toBe(SESSION_TTL_SECONDS);
    expect(reply.setCookieCalls[0].opts.secure).toBe(true);
    expect(reply.setCookieCalls[0].opts.httpOnly).toBe(true);
    expect(reply.setCookieCalls[0].opts.sameSite).toBe('strict');
  });
});