import { nextTestSetup } from 'e2e-utils' import { retry } from 'next-test-utils' describe('back/forward cache', () => { const { next } = nextTestSetup({ files: __dirname, }) it('React state is preserved when navigating with back/forward buttons', async () => { const browser = await next.browser('/page/1') // Accumulate some state on page 1. await retry(async () => { // we do this inside of retry in case button event handler // isn't ready yet await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 1') }) await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 2') // Navigate to page 2. Accumulate some state here, too. const linkToPage2 = await browser.elementByCss('a[href="/page/2"]') await linkToPage2.click() const incrementButton2 = await browser.elementById('increment-button-2') const counterDisplay2 = await browser.elementById('counter-display-2') await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() expect(await counterDisplay2.text()).toBe('Count: 9') // Navigate back to page 1. Its state should be preserved. await browser.back() const counterDisplay1AfterNav = await browser.elementById('counter-display-1') expect(await counterDisplay1AfterNav.text()).toBe('Count: 2') // Navigate forward to page 2. Its state should be preserved. await browser.forward() const counterDisplay2AfterNav = await browser.elementById('counter-display-2') expect(await counterDisplay2AfterNav.text()).toBe('Count: 9') }) it('React state is preserved when navigating back/forward with links', async () => { const browser = await next.browser('/page/1') // Accumulate some state on page 1. // Accumulate some state on page 1. await retry(async () => { // we do this inside of retry in case button event handler // isn't ready yet await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 1') }) await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 2') // Navigate to page 2. Accumulate some state here, too. const linkToPage2 = await browser.elementByCss('a[href="/page/2"]') await linkToPage2.click() const incrementButton2 = await browser.elementById('increment-button-2') const counterDisplay2 = await browser.elementById('counter-display-2') await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() expect(await counterDisplay2.text()).toBe('Count: 9') // Navigate back to page 1. Its state should be preserved. const linkToPage1 = await browser.elementByCss('a[href="/page/1"]') await linkToPage1.click() const counterDisplay1AfterNav = await browser.elementById('counter-display-1') expect(await counterDisplay1AfterNav.text()).toBe('Count: 2') // Navigate back to page 2. Its state should be preserved. await linkToPage2.click() const counterDisplay2AfterNav = await browser.elementById('counter-display-2') expect(await counterDisplay2AfterNav.text()).toBe('Count: 9') }) it('React state is preserved when navigating back to a page with different search params than before ', async () => { const browser = await next.browser('/page/1') // Accumulate some state on page 1. await retry(async () => { // we do this inside of retry in case button event handler // isn't ready yet await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 1') }) await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 2') // Navigate to page 2. const linkToPage2 = await browser.elementByCss('a[href="/page/2"]') await linkToPage2.click() // Navigate back to page 1, but with a different search param. const linkToPage1WithSearchParam = await browser.elementByCss( 'a[href="/page/1?param=true"]' ) await linkToPage1WithSearchParam.click() await retry(async () => { const counterDisplay1AfterNav = await browser.elementById('counter-display-1') const hasSearchParam = await browser.elementById('has-search-param-1') expect(await counterDisplay1AfterNav.text()).toBe('Count: 2') expect(await hasSearchParam.text()).toBe('Has search param: yes') }) }) it('bfcache only preserves up to N entries', async () => { // The current limit is hardcoded to 3. const browser = await next.browser('/page/1') await retry(async () => { expect(await browser.elementByCss('h2').text()).toEqual('Page 1') }) // Accumulate some state on page 1. await retry(async () => { // we do this inside of retry in case button event handler // isn't ready yet await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 1') }) await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 2') // Navigate to page 2. Accumulate some state here, too. const linkToPage2 = await browser.elementByCss('a[href="/page/2"]') await linkToPage2.click() await retry(async () => { expect(await browser.elementByCss('h2').text()).toEqual('Page 2') }) const incrementButton2 = await browser.elementById('increment-button-2') const counterDisplay2 = await browser.elementById('counter-display-2') await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() expect(await counterDisplay2.text()).toBe('Count: 9') // Navigate to 2 additional pages. const linkToPage3 = await browser.elementByCss('a[href="/page/3"]') await linkToPage3.click() await retry(async () => { expect(await browser.elementByCss('h2').text()).toEqual('Page 3') }) const linkToPage4 = await browser.elementByCss('a[href="/page/4"]') await linkToPage4.click() await retry(async () => { expect(await browser.elementByCss('h2').text()).toEqual('Page 4') }) // The bfcache size is now 4. Because the limit is 3, page 1 should have // been evicted, but not page 2. // Navigate to page 2 to confirm its state is preserved. await linkToPage2.click() await retry(async () => { expect(await browser.elementByCss('h2').text()).toEqual('Page 2') }) const counterDisplay2AfterNav = await browser.elementById('counter-display-2') expect(await counterDisplay2AfterNav.text()).toBe('Count: 9') // Navigate back to page 1 to confirm its state is not preserved. const linkToPage1 = await browser.elementByCss('a[href="/page/1"]') await linkToPage1.click() await retry(async () => { expect(await browser.elementByCss('h2').text()).toEqual('Page 1') }) const counterDisplay1AfterNav = await browser.elementById('counter-display-1') expect(await counterDisplay1AfterNav.text()).toBe('Count: 0') }) it('navigate back and forth repeatedly between the same pages without evicting', async () => { // The current limit is hardcoded to 3. const browser = await next.browser('/page/1') // Accumulate some state on page 1. await retry(async () => { // we do this inside of retry in case button event handler // isn't ready yet await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 1') }) await browser.elementById('increment-button-1').click() const counterDisplay1 = await browser.elementById('counter-display-1') expect(await counterDisplay1.text()).toBe('Count: 2') // Navigate to page 2. Accumulate some state here, too. const linkToPage2 = await browser.elementByCss('a[href="/page/2"]') await linkToPage2.click() const incrementButton2 = await browser.elementById('increment-button-2') const counterDisplay2 = await browser.elementById('counter-display-2') await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() await incrementButton2.click() expect(await counterDisplay2.text()).toBe('Count: 9') // Navigate between pages 1 and 2 repeatedly const linkToPage1 = await browser.elementByCss('a[href="/page/1"]') await linkToPage1.click() await linkToPage2.click() await linkToPage1.click() await linkToPage2.click() await linkToPage1.click() await linkToPage2.click() // Confirm the state is preserved on both pages. const counterDisplay2AfterNav = await browser.elementById('counter-display-2') expect(await counterDisplay2AfterNav.text()).toBe('Count: 9') await linkToPage1.click() const counterDisplay1AfterNav = await browser.elementById('counter-display-1') expect(await counterDisplay1AfterNav.text()).toBe('Count: 2') }) })