import { createNext, FileRef } from 'e2e-utils' import { NextInstance } from 'e2e-utils' import { join } from 'path' import { fetchViaHTTP, waitFor } from 'next-test-utils' describe('app-dir-prevent-304-caching', () => { let next: NextInstance beforeAll(async () => { next = await createNext({ files: { 'next.config.js': new FileRef(join(__dirname, 'next.config.js')), app: new FileRef(join(__dirname, 'app')), }, }) }) afterAll(() => next.destroy()) // https://github.com/vercel/next.js/issues/56580 it('should not cache 304 status', async () => { // Fresh call const rFresh = await fetchViaHTTP(next.url, '/') expect(rFresh.status).toBe(200) await waitFor(500) // Cache HIT but still 200 const rHit = await fetchViaHTTP( next.url, '/', {}, { headers: { 'If-None-Match': rFresh.headers.get('etag'), }, } ) expect(rHit.status).toBe(200) await waitFor(500) // Here happens the race condition const r304 = await fetchViaHTTP( next.url, '/', {}, { headers: { 'If-None-Match': rHit.headers.get('etag'), }, } ) expect(r304.status).toBe(304) // ... Postponed but should not save 304 ... await waitFor(1000) // Now without cache headers should 200 const rStillFresh = await fetchViaHTTP(next.url, '/') expect(rStillFresh.status).toBe(200) }) })