File size: 10,663 Bytes
1e92f2d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
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')
  })
})