@guardian/paparazzi

Paparazzi

📸 Automated manual visual regression testing

Sometimes you are working in a project with a couple of GET routes and you are changing an element that's quite global and you want to make sure you aren't accidentally breaking some obscure part of the site sitting elsewhere. If this is you please keep reading!

Paparazzi spins up a ton of chrome instances using puppeteer and takes screenshots of all paths you specify at all sizes you specify.

Install and setup

npm i -g @guardian/paparazzi

This will install the paparazzi cli tool. You can also use npx instead.

Then in the folder you want to run tests for (this could be your project folder, for instance), create a .paparazzirc config file, it's JSON and here's an example:

{
  // List of routes you wanna screenshot
  "routes": [
    "uk",
    "showcase",
    "uk/subscribe",
    "uk/subscribe/paper",
    "uk/subscribe/digital",
    "uk/subscribe/weekly",
    "uk/contribute",
    "uk/contribute/recurring",
    "paypal/return"
  ],

  // Domain you want to test the routes against
  "prefix": "https://support.thegulocal.com/",

  // [optional] Name of the folder where screenshots will go to
  "out": "screenies",

  // [optional] Extra options for puppeteer's page.screenshot
  "screenshot": {
    "omitBackground": true,
    "fullPage": true
  },

  // [optional] Screen size pairs
  "sizes": {
    "desktop": {
      "width": 1440,
      "height": 900
    },
    "phone": {
      "width": 375,
      "height": 1100
    },
    "tablet": {
      "height": 1024,
      "width": 768
    }
  }
}

Now run paparazzi or npx @guardian/paparazzi and watch the screenshots appear in front of your eyes.

Can I set this up as a CI step?

That would be awesome! If you do please let us know and we'll add it to the docs. A great use case would be to automatically add screenshots on your PRs as a comment.

Help! my computer caught fire

Paparazzi spins a whole chrome instance per route, this is not efficient and can break havoc when using many routes. There are solutions that can be implemented such as this. PRs welcome!