撰寫測試

測試執行器框架支援

@wdio/visual-service 與測試執行器框架無關，這表示您可以使用它和 WebdriverIO 支援的所有框架，例如

• Mocha
• Jasmine
• CucumberJS

在您的測試中，您可以儲存螢幕截圖，或將正在測試的應用程式的目前視覺狀態與基準進行比對。為此，此服務提供了自訂匹配器，以及檢查方法

Mocha

describe('Mocha Example', () => {
    beforeEach(async () => {
        await browser.url('https://webdriverio.dev.org.tw')
    })

    it('using visual matchers to assert against baseline', async () => {
        // Check screen to exactly match with baseline
        await expect(browser).toMatchScreenSnapshot('partialPage')
        // check an element to have a mismatch percentage of 5% with the baseline
        await expect(browser).toMatchScreenSnapshot('partialPage', 5)
        // check an element with options for `saveScreen` command
        await expect(browser).toMatchScreenSnapshot('partialPage', {
            /* some options */
        })

        // Check an element to exactly match with baseline
        await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement')
        // check an element to have a mismatch percentage of 5% with the baseline
        await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement', 5)
        // check an element with options for `saveElement` command
        await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement', {
            /* some options */
        })

        // Check a full page screenshot match with baseline
        await expect(browser).toMatchFullPageSnapshot('fullPage')
        // Check a full page screenshot to have a mismatch percentage of 5% with the baseline
        await expect(browser).toMatchFullPageSnapshot('fullPage', 5)
        // Check a full page screenshot with options for `checkFullPageScreen` command
        await expect(browser).toMatchFullPageSnapshot('fullPage', {
            /* some options */
        })

        // Check a full page screenshot with all tab executions
        await expect(browser).toMatchTabbablePageSnapshot('check-tabbable')
        // Check a full page screenshot to have a mismatch percentage of 5% with the baseline
        await expect(browser).toMatchTabbablePageSnapshot('check-tabbable', 5)
        // Check a full page screenshot with options for `checkTabbablePage` command
        await expect(browser).toMatchTabbablePageSnapshot('check-tabbable', {
            /* some options */
        })
    })

    it('should save some screenshots', async () => {
        // Save a screen
        await browser.saveScreen('examplePage', {
            /* some options */
        })

        // Save an element
        await browser.saveElement(
            await $('#element-id'),
            'firstButtonElement',
            {
                /* some options */
            }
        )

        // Save a full page screenshot
        await browser.saveFullPageScreen('fullPage', {
            /* some options */
        })

        // Save a full page screenshot with all tab executions
        await browser.saveTabbablePage('save-tabbable', {
            /* some options, use the same options as for saveFullPageScreen */
        })
    })

    it('should compare successful with a baseline', async () => {
        // Check a screen
        await expect(
            await browser.checkScreen('examplePage', {
                /* some options */
            })
        ).toEqual(0)

        // Check an element
        await expect(
            await browser.checkElement(
                await $('#element-id'),
                'firstButtonElement',
                {
                    /* some options */
                }
            )
        ).toEqual(0)

        // Check a full page screenshot
        await expect(
            await browser.checkFullPageScreen('fullPage', {
                /* some options */
            })
        ).toEqual(0)

        // Check a full page screenshot with all tab executions
        await expect(
            await browser.checkTabbablePage('check-tabbable', {
                /* some options, use the same options as for checkFullPageScreen */
            })
        ).toEqual(0)
    })
})

Jasmine

describe('Jasmine Example', () => {
    beforeEach(async () => {
        await browser.url('https://webdriverio.dev.org.tw')
    })

    it('using visual matchers to assert against baseline', async () => {
        // Check screen to exactly match with baseline
        await expect(browser).toMatchScreenSnapshot('partialPage')
        // check an element to have a mismatch percentage of 5% with the baseline
        await expect(browser).toMatchScreenSnapshot('partialPage', 5)
        // check an element with options for `saveScreen` command
        await expect(browser).toMatchScreenSnapshot('partialPage', {
            /* some options */
        })

        // Check an element to exactly match with baseline
        await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement')
        // check an element to have a mismatch percentage of 5% with the baseline
        await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement', 5)
        // check an element with options for `saveElement` command
        await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement', {
            /* some options */
        })

        // Check a full page screenshot match with baseline
        await expect(browser).toMatchFullPageSnapshot('fullPage')
        // Check a full page screenshot to have a mismatch percentage of 5% with the baseline
        await expect(browser).toMatchFullPageSnapshot('fullPage', 5)
        // Check a full page screenshot with options for `checkFullPageScreen` command
        await expect(browser).toMatchFullPageSnapshot('fullPage', {
            /* some options */
        })

        // Check a full page screenshot with all tab executions
        await expect(browser).toMatchTabbablePageSnapshot('check-tabbable')
        // Check a full page screenshot to have a mismatch percentage of 5% with the baseline
        await expect(browser).toMatchTabbablePageSnapshot('check-tabbable', 5)
        // Check a full page screenshot with options for `checkTabbablePage` command
        await expect(browser).toMatchTabbablePageSnapshot('check-tabbable', {
            /* some options */
        })
    })

    it('should save some screenshots', async () => {
        // Save a screen
        await browser.saveScreen('examplePage', {
            /* some options */
        })

        // Save an element
        await browser.saveElement(
            await $('#element-id'),
            'firstButtonElement',
            {
                /* some options */
            }
        )

        // Save a full page screenshot
        await browser.saveFullPageScreen('fullPage', {
            /* some options */
        })

        // Save a full page screenshot with all tab executions
        await browser.saveTabbablePage('save-tabbable', {
            /* some options, use the same options as for saveFullPageScreen */
        })
    })

    it('should compare successful with a baseline', async () => {
        // Check a screen
        await expect(
            await browser.checkScreen('examplePage', {
                /* some options */
            })
        ).toEqual(0)

        // Check an element
        await expect(
            await browser.checkElement(
                await $('#element-id'),
                'firstButtonElement',
                {
                    /* some options */
                }
            )
        ).toEqual(0)

        // Check a full page screenshot
        await expect(
            await browser.checkFullPageScreen('fullPage', {
                /* some options */
            })
        ).toEqual(0)

        // Check a full page screenshot with all tab executions
        await expect(
            await browser.checkTabbablePage('check-tabbable', {
                /* some options, use the same options as for checkFullPageScreen */
            })
        ).toEqual(0)
    })
})

CucumberJS

import { When, Then } from '@wdio/cucumber-framework'

When('I save some screenshots', async function () {
    // Save a screen
    await browser.saveScreen('examplePage', {
        /* some options */
    })

    // Save an element
    await browser.saveElement(await $('#element-id'), 'firstButtonElement', {
        /* some options */
    })

    // Save a full page screenshot
    await browser.saveFullPageScreen('fullPage', {
        /* some options */
    })

    // Save a full page screenshot with all tab executions
    await browser.saveTabbablePage('save-tabbable', {
        /* some options, use the same options as for saveFullPageScreen */
    })
})

Then('I should be able to match some screenshots with a baseline', async function () {
    // Check screen to exactly match with baseline
    await expect(browser).toMatchScreenSnapshot('partialPage')
    // check an element to have a mismatch percentage of 5% with the baseline
    await expect(browser).toMatchScreenSnapshot('partialPage', 5)
    // check an element with options for `saveScreen` command
    await expect(browser).toMatchScreenSnapshot('partialPage', {
        /* some options */
    })

    // Check an element to exactly match with baseline
    await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement')
    // check an element to have a mismatch percentage of 5% with the baseline
    await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement', 5)
    // check an element with options for `saveElement` command
    await expect($('#element-id')).toMatchElementSnapshot('firstButtonElement', {
        /* some options */
    })

    // Check a full page screenshot match with baseline
    await expect(browser).toMatchFullPageSnapshot('fullPage')
    // Check a full page screenshot to have a mismatch percentage of 5% with the baseline
    await expect(browser).toMatchFullPageSnapshot('fullPage', 5)
    // Check a full page screenshot with options for `checkFullPageScreen` command
    await expect(browser).toMatchFullPageSnapshot('fullPage', {
        /* some options */
    })

    // Check a full page screenshot with all tab executions
    await expect(browser).toMatchTabbablePageSnapshot('check-tabbable')
    // Check a full page screenshot to have a mismatch percentage of 5% with the baseline
    await expect(browser).toMatchTabbablePageSnapshot('check-tabbable', 5)
    // Check a full page screenshot with options for `checkTabbablePage` command
    await expect(browser).toMatchTabbablePageSnapshot('check-tabbable', {
        /* some options */
    })
})

Then('I should be able to compare some screenshots with a baseline', async function () {
    // Check a screen
    await expect(
        await browser.checkScreen('examplePage', {
            /* some options */
        })
    ).toEqual(0)

    // Check an element
    await expect(
        await browser.checkElement(
            await $('#element-id'),
            'firstButtonElement',
            {
                /* some options */
            }
        )
    ).toEqual(0)

    // Check a full page screenshot
    await expect(
        await browser.checkFullPageScreen('fullPage', {
            /* some options */
        })
    ).toEqual(0)

    // Check a full page screenshot with all tab executions
    await expect(
        await browser.checkTabbablePage('check-tabbable', {
            /* some options, use the same options as for checkFullPageScreen */
        })
    ).toEqual(0)
})

重要

此服務提供 save 和 check 方法。如果您是第一次執行測試，則 不應 合併 save 和 compare 方法，check 方法會自動為您建立基準影像

#####################################################################################
 INFO:
 Autosaved the image to
 /Users/wswebcreation/sample/baselineFolder/desktop_chrome/examplePage-chrome-latest-1366x768.png
#####################################################################################

當您停用自動儲存基準影像時，Promise 將會以以下警告遭到拒絕。

#####################################################################################
 Baseline image not found, save the actual image manually to the baseline.
 The image can be found here:
 /Users/wswebcreation/sample/.tmp/actual/desktop_chrome/examplePage-chrome-latest-1366x768.png
#####################################################################################

這表示目前的螢幕截圖會儲存在實際資料夾中，並且您需要手動將其複製到您的基準。如果您使用 autoSaveBaseline: true 實例化 @wdio/visual-service，則影像會自動儲存到基準資料夾中。