编写测试

测试运行器框架支持

@wdio/visual-service 与测试运行器框架无关，这意味着您可以将其与 WebdriverIO 支持的所有框架一起使用，例如

• Mocha
• Jasmine
• CucumberJS

在您的测试中，您可以保存屏幕截图或将被测应用程序的当前视觉状态与基线进行匹配。为此，该服务提供了自定义匹配器以及检查方法

Mocha

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

    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.node.org.cn')
    })

    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

此服务提供save和check方法。如果您第一次运行测试，则不应组合使用save和compare方法，check方法会自动为您创建基线图像。

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

当您禁用自动保存基线图像时，Promise 将被以下警告拒绝。

#####################################################################################
 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
#####################################################################################

这意味着当前屏幕截图已保存在实际文件夹中，您需要手动将其复制到您的基线。如果您使用autoSaveBaseline: true实例化@wdio/visual-service，则图像将自动保存到基线文件夹中。