import { nextTestSetup } from 'e2e-utils' import { check, waitFor, retry } from 'next-test-utils' import { NEXT_RSC_UNION_QUERY } from 'next/dist/client/components/app-router-headers' import { computeCacheBustingSearchParam } from 'next/dist/shared/lib/router/utils/cache-busting-search-param' const browserConfigWithFixedTime = { beforePageLoad: (page) => { page.addInitScript(() => { const startTime = new Date() const fixedTime = new Date('2023-04-17T00:00:00Z') // Override the Date constructor // @ts-ignore // eslint-disable-next-line no-native-reassign Date = class extends Date { constructor() { super() // @ts-ignore return new startTime.constructor(fixedTime) } static now() { return fixedTime.getTime() } } }) }, } const itHeaded = process.env.HEADLESS ? it.skip : it describe('app dir - prefetching', () => { const { next, isNextDev, isNextDeploy } = nextTestSetup({ files: __dirname, }) // TODO: re-enable for dev after https://vercel.slack.com/archives/C035J346QQL/p1663822388387959 is resolved (Sep 22nd 2022) if (isNextDev) { it('should skip next dev for now', () => {}) return } it('NEXT_RSC_UNION_QUERY query name is _rsc', async () => { expect(NEXT_RSC_UNION_QUERY).toBe('_rsc') }) it('should show layout eagerly when prefetched with loading one level down', async () => { const browser = await next.browser('/', browserConfigWithFixedTime) // Ensure the page is prefetched await waitFor(1000) const before = Date.now() await browser .elementByCss('#to-dashboard') .click() .waitForElementByCss('#dashboard-layout') const after = Date.now() const timeToComplete = after - before expect(timeToComplete).toBeLessThan(1000) expect(await browser.elementByCss('#dashboard-layout').text()).toBe( 'Dashboard Hello World' ) await browser.waitForElementByCss('#dashboard-page') expect(await browser.waitForElementByCss('#dashboard-page').text()).toBe( 'Welcome to the dashboard' ) }) it('should not have prefetch error for static path', async () => { const browser = await next.browser('/') await browser.eval('window.nd.router.prefetch("/dashboard/123")') await waitFor(3000) await browser.eval('window.nd.router.push("/dashboard/123")') expect(next.cliOutput).not.toContain('ReferenceError') expect(next.cliOutput).not.toContain('is not defined') }) it('should not have prefetch error when reloading before prefetch request is finished', async () => { const browser = await next.browser('/') await browser.eval('window.next.router.prefetch("/dashboard/123")') await browser.refresh() const logs = await browser.log() expect(logs).not.toMatchObject( expect.arrayContaining([ expect.objectContaining({ message: expect.stringContaining('Failed to fetch RSC payload'), }), ]) ) }) itHeaded('should not suppress prefetches after navigating back', async () => { // Force headed mode, as bfcache is not available in headless mode. const browser = await next.browser('/', { headless: false }) // Trigger a hard navigation. await browser.elementById('to-static-page-hard').click() // Go back, utilizing the bfcache. await browser.elementById('go-back').click() let requests: string[] = [] browser.on('request', (req) => { requests.push(new URL(req.url()).pathname) }) await browser.eval('window.next.router.prefetch("/dashboard/123")') await browser.waitForIdleNetwork() expect(requests).toInclude('/dashboard/123') }) it('should not fetch again when a static page was prefetched', async () => { const browser = await next.browser('/404', browserConfigWithFixedTime) let requests: string[] = [] browser.on('request', (req) => { requests.push(new URL(req.url()).pathname) }) await browser.eval('location.href = "/"') await browser.eval( 'window.nd.router.prefetch("/static-page", {kind: "auto"})' ) await check(() => { return requests.some( (req) => req.includes('static-page') && !req.includes(NEXT_RSC_UNION_QUERY) ) ? 'success' : JSON.stringify(requests) }, 'success') await browser .elementByCss('#to-static-page') .click() .waitForElementByCss('#static-page') expect( requests.filter((request) => request === '/static-page').length ).toBe(1) // return to the home page await browser.elementByCss('#to-home').click() await browser.waitForElementByCss('#to-static-page') // there shouldn't be any additional prefetches expect( requests.filter((request) => request === '/static-page').length ).toBe(1) // navigate to the static page again await browser.elementByCss('#to-static-page').click() await browser.waitForElementByCss('#static-page') // there still should only be the initial request to the static page expect( requests.filter((request) => request === '/static-page').length ).toBe(1) }) it('should calculate `_rsc` query based on `Next-Url`', async () => { const browser = await next.browser('/404', browserConfigWithFixedTime) let staticPageRequests: string[] = [] browser.on('request', (req) => { const url = new URL(req.url()) if (url.toString().includes(`/static-page?${NEXT_RSC_UNION_QUERY}=`)) { staticPageRequests.push(`${url.pathname}${url.search}`) } }) await browser.eval('location.href = "/"') await browser.eval( `window.nd.router.prefetch("/static-page", {kind: "auto"})` ) await check(() => { return staticPageRequests.length === 1 ? 'success' : JSON.stringify(staticPageRequests) }, 'success') // Unable to clear router cache so mpa navigation await browser.eval('location.href = "/dashboard"') await browser.eval( `window.nd.router.prefetch("/static-page", {kind: "auto"})` ) await check(() => { return staticPageRequests.length === 2 ? 'success' : JSON.stringify(staticPageRequests) }, 'success') expect(staticPageRequests[0]).toMatch('/static-page?_rsc=') expect(staticPageRequests[1]).toMatch('/static-page?_rsc=') // `_rsc` does not match because it depends on the `Next-Url` expect(staticPageRequests[0]).not.toBe(staticPageRequests[1]) }) it('should not prefetch for a bot user agent', async () => { const browser = await next.browser('/404') let requests: string[] = [] browser.on('request', (req) => { requests.push(new URL(req.url()).pathname) }) await browser.eval( `location.href = "/?useragent=${encodeURIComponent( 'Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/W.X.Y.Z Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)' )}"` ) await browser.elementByCss('#to-static-page').moveTo() // check five times to ensure prefetch didn't occur for (let i = 0; i < 5; i++) { await waitFor(500) expect( requests.filter( (request) => request === '/static-page' || request.includes(NEXT_RSC_UNION_QUERY) ).length ).toBe(0) } }) it('should navigate when prefetch is false', async () => { const browser = await next.browser('/prefetch-false/initial') await browser .elementByCss('#to-prefetch-false-result') .click() .waitForElementByCss('#prefetch-false-page-result') expect( await browser.elementByCss('#prefetch-false-page-result').text() ).toBe('Result page') }) it('should not need to prefetch the layout if the prefetch is initiated at the same segment', async () => { const stateTree = encodeURIComponent( JSON.stringify([ '', { children: [ 'prefetch-auto', { children: [ ['slug', 'justputit', 'd'], { children: ['__PAGE__', {}] }, ], }, ], }, null, null, true, ]) ) const response = await next.fetch(`/prefetch-auto/justputit?_rsc=dcqtr`, { headers: { RSC: '1', 'Next-Router-Prefetch': '1', 'Next-Router-State-Tree': stateTree, 'Next-Url': '/prefetch-auto/justputit', }, }) const prefetchResponse = await response.text() expect(prefetchResponse).not.toContain('Page Data!') expect(prefetchResponse).not.toContain('Layout Data!') expect(prefetchResponse).not.toContain('Loading Prefetch Auto') }) it('should only prefetch the loading state and not the component tree when prefetching at the same segment', async () => { const stateTree = encodeURIComponent( JSON.stringify([ '', { children: [ 'prefetch-auto', { children: [ ['slug', 'vercel', 'd'], { children: ['__PAGE__', {}] }, ], }, ], }, null, null, true, ]) ) const headers = { RSC: '1', 'Next-Router-Prefetch': '1', 'Next-Router-State-Tree': stateTree, 'Next-Url': '/prefetch-auto/vercel', } const url = new URL('/prefetch-auto/justputit', 'http://localhost') const cacheBustingParam = computeCacheBustingSearchParam( headers['Next-Router-Prefetch'], undefined, headers['Next-Router-State-Tree'], headers['Next-Url'] ) if (cacheBustingParam) { url.searchParams.set('_rsc', cacheBustingParam) } const response = await next.fetch(url.toString(), { headers }) const prefetchResponse = await response.text() expect(prefetchResponse).not.toContain('Page Data!') expect(prefetchResponse).toContain('Loading Prefetch Auto') }) it('should not re-render error component when triggering a prefetch action', async () => { const browser = await next.browser('/with-error') const initialRandom = await browser .elementByCss('button') .click() .waitForElementByCss('#random-number') .text() await browser.eval('window.next.router.prefetch("/")') // confirm the error component was not re-rendered expect(await browser.elementById('random-number').text()).toBe( initialRandom ) }) it('should immediately render the loading state for a dynamic segment when fetched from higher up in the tree', async () => { const browser = await next.browser('/') const loadingText = await browser .elementById('to-dynamic-page') .click() .waitForElementByCss('#loading-text') .text() expect(loadingText).toBe('Loading Prefetch Auto') await browser.waitForElementByCss('#prefetch-auto-page-data') }) it('should not unintentionally modify the requested prefetch by escaping the uri encoded query params', async () => { const rscRequests = [] const browser = await next.browser('/uri-encoded-prefetch', { beforePageLoad(page) { page.on('request', async (req) => { const url = new URL(req.url()) if (url.searchParams.has('_rsc')) { rscRequests.push(url.pathname + url.search) } }) }, }) // sanity check: the link should be present expect(await browser.elementById('prefetch-via-link')).toBeDefined() await browser.waitForIdleNetwork() // The space encoding of the prefetch request should be the same as the href, and should not be replaced with a + await retry(async () => { expect( rscRequests.filter((req) => req.includes('/?param=with%20space')) ).toHaveLength(1) }) // Click the link await browser.elementById('prefetch-via-link').click() // Assert that we're on the homepage expect(await browser.hasElementByCssSelector('#to-dashboard')).toBe(true) await browser.waitForIdleNetwork() // No new requests should be made since it is correctly prefetched await retry(async () => { expect( rscRequests.filter((req) => req.includes('/?param=with%20space')) ).toHaveLength(1) }) }) describe('prefetch cache seeding', () => { it('should not re-fetch the initial static page if the same page is prefetched with prefetch={true}', async () => { const rscRequests = [] const browser = await next.browser('/static-page', { beforePageLoad(page) { page.on('request', async (req) => { const url = new URL(req.url()) if (url.pathname === '/static-page' || url.pathname === '/') { const headers = await req.allHeaders() if (headers['rsc']) { rscRequests.push(url.pathname) } } }) }, }) expect( await browser.hasElementByCssSelector('[href="/static-page"]') ).toBe(true) // sanity check: we should see a prefetch request to the root page await retry(async () => { expect(rscRequests.filter((req) => req === '/').length).toBe(1) }) // We shouldn't see any requests to the static page since the prefetch cache was seeded as part of the SSR render await retry(async () => { expect(rscRequests.filter((req) => req === '/static-page').length).toBe( 0 ) }) // navigate to index await browser.elementByCss('[href="/"]').click() // we should be on the index page await browser.waitForElementByCss('#to-dashboard') // navigate to the static page await browser.elementByCss('[href="/static-page"]').click() // we should be on the static page await browser.waitForElementByCss('#static-page') await browser.waitForIdleNetwork() // We still shouldn't see any requests since it respects the static staletime (default 5m) await retry(async () => { expect(rscRequests.filter((req) => req === '/static-page').length).toBe( 0 ) }) }) it('should not re-fetch the initial dynamic page if the same page is prefetched with prefetch={true}', async () => { const rscRequests = [] const browser = await next.browser('/dynamic-page', { beforePageLoad(page) { page.on('request', async (req) => { const url = new URL(req.url()) if (url.pathname === '/dynamic-page' || url.pathname === '/') { const headers = await req.allHeaders() if (headers['rsc']) { rscRequests.push(url.pathname) } } }) }, }) expect( await browser.hasElementByCssSelector('[href="/dynamic-page"]') ).toBe(true) // sanity check: we should see a prefetch request to the root page await retry(async () => { expect(rscRequests.filter((req) => req === '/').length).toBe(1) }) // We shouldn't see any requests to the dynamic page since the prefetch cache was seeded as part of the SSR render await retry(async () => { expect( rscRequests.filter((req) => req === '/dynamic-page').length ).toBe(0) }) // navigate to index await browser.elementByCss('[href="/"]').click() // we should be on the index page await browser.waitForElementByCss('#to-dashboard') // navigate to the dynamic page await browser.elementByCss('[href="/dynamic-page"]').click() // we should be on the dynamic page await browser.waitForElementByCss('#dynamic-page') await browser.waitForIdleNetwork() // We should see a request for the dynamic page since it respects the dynamic staletime (default 0) await retry(async () => { expect( rscRequests.filter((req) => req === '/dynamic-page').length ).toBe(1) }) }) }) // These tests are skipped when deployed as they rely on runtime logs if (!isNextDeploy) { describe('dynamic rendering', () => { describe.each(['/force-dynamic', '/revalidate-0'])('%s', (basePath) => { it('should not re-render layout when navigating between sub-pages', async () => { const logStartIndex = next.cliOutput.length const browser = await next.browser(`${basePath}/test-page`) let initialRandomNumber = await browser .elementById('random-number') .text() await browser .elementByCss(`[href="${basePath}/test-page/sub-page"]`) .click() await check(() => browser.hasElementByCssSelector('#sub-page'), true) const newRandomNumber = await browser .elementById('random-number') .text() expect(initialRandomNumber).toBe(newRandomNumber) await check(() => { const logOccurrences = next.cliOutput.slice(logStartIndex).split('re-fetching in layout') .length - 1 return logOccurrences }, 1) }) it('should update search params following a link click', async () => { const browser = await next.browser(`${basePath}/search-params`) await check( () => browser.elementById('search-params-data').text(), /{}/ ) await browser.elementByCss('[href="?foo=true"]').click() await check( () => browser.elementById('search-params-data').text(), /{"foo":"true"}/ ) await browser .elementByCss(`[href="${basePath}/search-params"]`) .click() await check( () => browser.elementById('search-params-data').text(), /{}/ ) await browser.elementByCss('[href="?foo=true"]').click() await check( () => browser.elementById('search-params-data').text(), /{"foo":"true"}/ ) }) }) }) } describe('invalid URLs', () => { it('should not throw when an invalid URL is passed to Link', async () => { const browser = await next.browser('/invalid-url/from-link') await check(() => browser.hasElementByCssSelector('h1'), true) expect(await browser.elementByCss('h1').text()).toEqual('Hello, world!') }) it('should throw when an invalid URL is passed to router.prefetch', async () => { const browser = await next.browser('/invalid-url/from-router-prefetch') await check(() => browser.hasElementByCssSelector('h1'), true) expect(await browser.elementByCss('h1').text()).toEqual( 'A prefetch threw an error' ) }) }) describe('fetch priority', () => { it('should prefetch links in viewport with low priority', async () => { const requests: { priority: string; url: string }[] = [] const browser = await next.browser('/', { beforePageLoad(page) { page.on('request', async (req) => { const url = new URL(req.url()) const headers = await req.allHeaders() if (headers['rsc']) { requests.push({ priority: headers['next-test-fetch-priority'], url: url.pathname, }) } }) }, }) await browser.waitForIdleNetwork() await retry(async () => { expect(requests.length).toBeGreaterThan(0) expect(requests.every((req) => req.priority === 'low')).toBe(true) }) }) it('should prefetch with high priority when navigating to a page without a prefetch entry', async () => { const requests: { priority: string; url: string }[] = [] const browser = await next.browser('/prefetch-false/initial', { beforePageLoad(page) { page.on('request', async (req) => { const url = new URL(req.url()) const headers = await req.allHeaders() if (headers['rsc']) { requests.push({ priority: headers['next-test-fetch-priority'], url: url.pathname, }) } }) }, }) await browser.waitForIdleNetwork() expect(requests.length).toBe(0) await browser.elementByCss('#to-prefetch-false-result').click() await retry(async () => { expect(requests.length).toBe(1) expect(requests[0].priority).toBe('high') }) }) it('should have an auto priority for all other fetch operations', async () => { const requests: { priority: string; url: string }[] = [] const browser = await next.browser('/', { beforePageLoad(page) { page.on('request', async (req) => { const url = new URL(req.url()) const headers = await req.allHeaders() if (headers['rsc']) { requests.push({ priority: headers['next-test-fetch-priority'], url: url.pathname, }) } }) }, }) await browser.elementByCss('#to-dashboard').click() await browser.waitForIdleNetwork() await retry(async () => { const dashboardRequests = requests.filter( (req) => req.url === '/dashboard' ) expect(dashboardRequests.length).toBe(2) expect(dashboardRequests[0].priority).toBe('low') // the first request is the prefetch expect(dashboardRequests[1].priority).toBe('auto') // the second request is the lazy fetch to fill in missing data }) }) it('should respect multiple prefetch types to the same URL', async () => { let interceptRequests = false const browser = await next.browser('/prefetch-race', { beforePageLoad(page) { page.route('**/force-dynamic/**', async (route) => { if (!interceptRequests) { return route.continue() } const request = route.request() const headers = await request.allHeaders() if (headers['rsc'] === '1') { // intentionally stall the request, // as after the initial page load, there shouldn't be any additional fetches // since the data should already be available. } else { await route.continue() } }) }, }) await browser.waitForIdleNetwork() interceptRequests = true await browser.elementByCss('[href="/force-dynamic/test-page"]').click() await browser.waitForElementByCss('#test-page') }) }) })