Small library that allows us to compare screenshots generated by puppeteer in our tests.
To use Puppeteer Screenshot Tester in your project, run:
yarn add --dev puppeteer-screenshot-tester
or
npm install --save-dev puppeteer-screenshot-tester
Require the puppeteer-screenshot-tester library:
const ScreenshotTester = require('puppeteer-screenshot-tester')const tester = await ScreenshotTester()const tester = await ScreenshotTester(
[threshold = 0][, includeAA = false[, ignoreColors = false[, matchingBox = { ignoreRectangles = [], includeRectangle = [] } [, errorSettings = Object [, outputSettings = Object]]]]]
)threshold<[number]> A threshold value <0,1> default set to 0, max ratio of difference between imagesincludeAA<[boolean]> Should include anti aliasing?ignoreColors<[boolean]> Should ignore colors?matchingBox<[Object]> Restrict what should be comparedmatchingBox.ignoreRectangles<[Array<Array[x, y, width, height]>]> Should ignore rectangles? example:[[325,170,100,40], [10,10,200,200]], X and Y should be the coordinates of the top-left cornermatchingBox.includeRectangle<[Array<Array[x, y, width, height]>]> Compare only part of screen? example:[[325,170,100,40], [10,10,200,200]], X and Y should be the coordinates of the top-left cornererrorSettings<[Object]> change how to display errors (errorType:flat|movement|flatDifferenceIntensity|movementDifferenceIntensity|diffOnly):{ errorColor: { red: 255, green: 0, blue: 255 }, errorType: 'flat', transparency: 0.7 }outputSettings<[Object]> change the output image settings:{ forceExt: 'jpeg' | 'png' | 'webp' | null, compressionLevel: 8 // 0-9 for .png, 0-100 otherwise overrides: {} // valid sharp options (see bellow) }- returns: <[function]> resolves to function
You can override options passed to sharp image processor. Just paste the overrides object that corresponds with sharp options:
const result = await tester(page)page<[BrowserPage]> BrowserPage returned by puppeteer when callingpuppeteer.launch().newPage()
const result = await tester(page[, name = 'test'[, screenshotOptions = {}]])name<[string]> name of created screenshot 'test' by defaultscreenshotOptions<[Object]> options passed to Puppeteer's screenshot method See the Puppeteer documentation for more info, plus the following keys:saveNewImageOnError: <[boolean]> saves the undiffed new image on error as${saveFolder}/${name}-new${ext}overwriteImageOnChange: <[boolean]> overwrites the reference image (${saveFolder}/${name}${ext}) on error / change
- <[boolean]> true if images are the same or there is no image to compare (first run)
const puppeteer = require('puppeteer')
const ScreenshotTester = require('puppeteer-screenshot-tester')
describe('google test', () => {
let originalTimeout
// extend default interval to 10s because some image processing might take some time
// we can do it beforeEach or once per test suite it's up to you
// if you're running that on fast computer/server probably won't need to do that
beforeEach(function() {
originalTimeout = jasmine.DEFAULT_TIMEOUT_INTERVAL
jasmine.DEFAULT_TIMEOUT_INTERVAL = 10000
})
// set default interval timeout for jasmine
afterEach(function() {
jasmine.DEFAULT_TIMEOUT_INTERVAL = originalTimeout
})
it(`check if google exists`, async () => {
// create ScreenshotTester with optional config
const tester = await ScreenshotTester(0.8, false, false, [], {
transparency: 0.5
}, { compressionLevel: 8 })
// setting up puppeteer
const browser = await puppeteer.launch()
const page = await browser.newPage()
await page.setViewport({width: 1920, height: 1080})
await page.goto('https://www.google.com', { waitUntil: 'networkidle0' })
await page.type('input[title="Search"]', 'Hello', { delay: 100 })
// call our tester with browser page returned by puppeteer browser
// second parameter is optional it's just a test name if provide that's filename
const result = await tester(page, 'test2', {
fullPage: true,
})
await browser.close()
// make assertion result is always boolean
expect(result).toBe(true)
})
})const tester = await ScreenshotTester(
0.1, // threshold
false, // anti-aliasing
false, // ignore colors
{
ignoreRectangles: [[650, 300, 700, 200]],
includeRectangles: [[300, 200, 1100, 1100]]
}, // rectangles
{
transparency: 0.5
}
)
Thanks goes to these wonderful people 😎 :
 Kemal Erdem 💻 📖 👀 |
 Max Harris 🐛 💻 |
 Andi Smith 📖 |
 JacobJust 💻 📖 |
This project follows the all-contributors specification. Contributions of any kind welcome!
![allcontributors[bot] avatar](https://avatars.githubusercontent.com/in/23186?v=4 "allcontributors[bot]")
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